Version 5.1.0

Bumps [coverage](https://github.com/coveragepy/coveragepy) from 7.15.0 to 7.15.2.
- [Release notes](https://github.com/coveragepy/coveragepy/releases)
- [Changelog](https://github.com/coveragepy/coveragepy/blob/main/CHANGES.rst)
- [Commits](https://github.com/coveragepy/coveragepy/compare/7.15.0...7.15.2)

---
updated-dependencies:
- dependency-name: coverage
  dependency-version: 7.15.2
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: ⬆
+  - package-ecosystem: "uv"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: ⬆

.github/workflows/build-release.yml

@@ -0,0 +1,29 @@
+name: Build Package
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  build-package:
+    runs-on: ubuntu-latest
+    environment: pypi
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Set up Python
+        run: uv python install 3.14
+
+      - name: Install dependencies
+        run: uv sync --group dev
+
+      - name: Build
+        run: uv build
+
+      - name: Publish package distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1

.github/workflows/ci.yml

@@ -0,0 +1,111 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    name: Lint (Ruff)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Set up Python
+        run: uv python install 3.13
+
+      - name: Install dependencies
+        run: uv sync --group dev
+
+      - name: Run Ruff linter
+        run: uv run ruff check .
+
+      - name: Run Ruff formatter check
+        run: uv run ruff format --check .
+
+  typecheck:
+    name: Type Check (ty)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Set up Python
+        run: uv python install 3.13
+
+      - name: Install dependencies
+        run: uv sync --group dev
+
+      - name: Run ty
+        run: uv run ty check
+
+  test:
+    name: Test (Python ${{ matrix.python-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.11", "3.12", "3.13", "3.14"]
+
+    services:
+      postgres:
+        image: postgres:18
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: test_db
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Set up Python ${{ matrix.python-version }}
+        run: uv python install ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: uv sync --group dev
+
+      - name: Run tests with coverage
+        env:
+          DATABASE_URL: postgresql+asyncpg://postgres:postgres@localhost:5432/test_db
+        run: |
+          uv run pytest --cov --cov-report=xml --cov-report=term-missing  --junitxml=junit.xml -o junit_family=legacy
+
+      - name: Upload coverage to Codecov
+        if: matrix.python-version == '3.14'
+        uses: codecov/codecov-action@v7
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          report_type: coverage
+          files: ./coverage.xml
+          fail_ci_if_error: false
+
+      - name: Upload test results to Codecov
+        if: matrix.python-version == '3.14'
+        uses: codecov/codecov-action@v7
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          report_type: test_results

.github/workflows/docs.yml

@@ -0,0 +1,53 @@
+name: Documentation
+
+on:
+  release:
+    types: [published]
+
+permissions:
+  contents: write
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v7
+
+      - name: Set up Python
+        run: uv python install 3.13
+
+      - run: uv sync --group dev
+
+      - name: Configure git
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+
+      - name: Deploy documentation
+        run: |
+          VERSION=${GITHUB_REF_NAME#v}
+          MAJOR=$(echo "$VERSION" | cut -d. -f1)
+          DEPLOY_VERSION="v$(echo "$VERSION" | cut -d. -f1-2)"
+
+          # On new major: keep only the latest feature version of the previous major
+          PREV_MAJOR=$((MAJOR - 1))
+          OLD_FEATURE_VERSIONS=$(uv run mike list 2>/dev/null | grep -oE "^v${PREV_MAJOR}\.[0-9]+" || true)
+
+          if [ -n "$OLD_FEATURE_VERSIONS" ]; then
+            LATEST_PREV=$(echo "$OLD_FEATURE_VERSIONS" | sort -t. -k2 -n | tail -1)
+            echo "$OLD_FEATURE_VERSIONS" | while read -r OLD_V; do
+              if [ "$OLD_V" != "$LATEST_PREV" ]; then
+                echo "Deleting $OLD_V"
+                uv run mike delete "$OLD_V"
+              fi
+            done
+          fi
+
+          uv run mike deploy --update-aliases "$DEPLOY_VERSION" stable
+          uv run mike set-default stable
+          git push origin gh-pages

.gitignore

@@ -0,0 +1,207 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[codz]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py.cover
+.hypothesis/
+.pytest_cache/
+cover/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+.pybuilder/
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# UV
+#   Similar to Pipfile.lock, it is generally recommended to include uv.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#uv.lock
+
+# poetry
+#   Similar to Pipfile.lock, it is generally recommended to include poetry.lock in version control.
+#   This is especially recommended for binary packages to ensure reproducibility, and is more
+#   commonly ignored for libraries.
+#   https://python-poetry.org/docs/basic-usage/#commit-your-poetrylock-file-to-version-control
+#poetry.lock
+#poetry.toml
+
+# pdm
+#   Similar to Pipfile.lock, it is generally recommended to include pdm.lock in version control.
+#   pdm recommends including project-wide configuration in pdm.toml, but excluding .pdm-python.
+#   https://pdm-project.org/en/latest/usage/project/#working-with-version-control
+#pdm.lock
+#pdm.toml
+.pdm-python
+.pdm-build/
+
+# pixi
+#   Similar to Pipfile.lock, it is generally recommended to include pixi.lock in version control.
+#pixi.lock
+#   Pixi creates a virtual environment in the .pixi directory, just like venv module creates one
+#   in the .venv directory. It is recommended not to include this directory in version control.
+.pixi
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.envrc
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# pytype static type analyzer
+.pytype/
+
+# Cython debug symbols
+cython_debug/
+
+# PyCharm
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/
+
+# Abstra
+# Abstra is an AI-powered process automation framework.
+# Ignore directories containing user credentials, local state, and settings.
+# Learn more at https://abstra.io/docs
+.abstra/
+
+# Visual Studio Code
+#  Visual Studio Code specific template is maintained in a separate VisualStudioCode.gitignore
+#  that can be found at https://github.com/github/gitignore/blob/main/Global/VisualStudioCode.gitignore
+#  and can be added to the global gitignore or merged into this file. However, if you prefer,
+#  you could uncomment the following to ignore the entire vscode folder
+# .vscode/
+
+# Ruff stuff:
+.ruff_cache/
+
+# PyPI configuration file
+.pypirc
+
+# Cursor
+#  Cursor is an AI-powered code editor. `.cursorignore` specifies files/directories to
+#  exclude from AI features like autocomplete and code analysis. Recommended for sensitive data
+#  refer to https://docs.cursor.com/context/ignore-files
+.cursorignore
+.cursorindexingignore
+
+# Marimo
+marimo/_static/
+marimo/_lsp/
+__marimo__/

.pre-commit-config.yaml

@@ -0,0 +1,34 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+    - repo: https://github.com/pre-commit/pre-commit-hooks
+      rev: v6.0.0
+      hooks:
+          - id: check-added-large-files
+            args: ["--maxkb=750"]
+            exclude: ^uv.lock$
+          - id: end-of-file-fixer
+          - id: trailing-whitespace
+
+    - repo: local
+      hooks:
+          - id: local-ruff-check
+            name: ruff check
+            entry: uv run ruff check --force-exclude --fix --exit-non-zero-on-fix .
+            require_serial: true
+            language: unsupported
+            types: [python]
+
+          - id: local-ruff-format
+            name: ruff format
+            entry: uv run ruff format --force-exclude --exit-non-zero-on-format .
+            require_serial: true
+            language: unsupported
+            types: [python]
+
+          - id: local-ty
+            name: ty check
+            entry: uv run ty check
+            require_serial: true
+            language: unsupported
+            pass_filenames: false

.python-version

@@ -0,0 +1 @@
+3.14

CNAME

@@ -1 +0,0 @@
-fastapi-toolsets.d3vyce.fr

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 d3vyce
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,69 @@
+# FastAPI Toolsets
+
+A modular collection of production-ready utilities for FastAPI. Install only what you need — from async CRUD and database helpers to CLI tooling, Prometheus metrics, and pytest fixtures. Each module is independently installable via optional extras, keeping your dependency footprint minimal.
+
+[![CI](https://github.com/d3vyce/fastapi-toolsets/actions/workflows/ci.yml/badge.svg)](https://github.com/d3vyce/fastapi-toolsets/actions/workflows/ci.yml)
+[![codecov](https://codecov.io/gh/d3vyce/fastapi-toolsets/graph/badge.svg)](https://codecov.io/gh/d3vyce/fastapi-toolsets)
+[![ty](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ty/main/assets/badge/v0.json)](https://github.com/astral-sh/ty)
+[![uv](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/uv/main/assets/badge/v0.json)](https://github.com/astral-sh/uv)
+[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)
+[![Python 3.11+](https://img.shields.io/badge/python-3.11+-blue.svg)](https://www.python.org/downloads/)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+
+---
+
+**Documentation**: [https://fastapi-toolsets.d3vyce.fr](https://fastapi-toolsets.d3vyce.fr)
+
+**Source Code**: [https://github.com/d3vyce/fastapi-toolsets](https://github.com/d3vyce/fastapi-toolsets)
+
+---
+
+## Installation
+
+The base package includes the core modules (CRUD, database, schemas, exceptions, fixtures, dependencies, model mixins, logging):
+
+```bash
+uv add fastapi-toolsets
+```
+
+Install only the extras you need:
+
+```bash
+uv add "fastapi-toolsets[cli]"
+uv add "fastapi-toolsets[metrics]"
+uv add "fastapi-toolsets[pytest]"
+```
+
+Or install everything:
+
+```bash
+uv add "fastapi-toolsets[all]"
+```
+
+## Features
+
+### Core
+
+- **CRUD**: Generic async CRUD operations with `CrudFactory`, built-in full-text/faceted search and Offset/Cursor pagination.
+- **Database**: Session management, transaction helpers, table locking, and polling-based row change detection
+- **Dependencies**: FastAPI dependency factories (`PathDependency`, `BodyDependency`) for automatic DB lookups from path or body parameters
+- **Fixtures**: Fixture system with dependency management, context support, and pytest integration
+- **Model Mixins**: SQLAlchemy mixins for common column patterns (`UUIDMixin`, `UUIDv7Mixin`, `CreatedAtMixin`, `UpdatedAtMixin`, `TimestampMixin`)
+- **Lifecycle Events**: Post-commit event system (`EventSession`, `listens_for`) that dispatches async/sync callbacks for insert, update, and delete operations
+- **Standardized API Responses**: Consistent response format with `Response`, `ErrorResponse`, `PaginatedResponse`, `CursorPaginatedResponse` and `OffsetPaginatedResponse`.
+- **Exception Handling**: Structured error responses with automatic OpenAPI documentation
+- **Logging**: Logging configuration with uvicorn integration via `configure_logging` and `get_logger`
+
+### Optional
+
+- **CLI**: Django-like command-line interface with fixture management and custom commands support
+- **Metrics**: Prometheus metrics endpoint with provider/collector registry
+- **Pytest Helpers**: Async test client, database session management, `pytest-xdist` support, and table cleanup utilities
+
+## License
+
+MIT License - see [LICENSE](LICENSE) for details.
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit issues and pull requests.

docs/examples/pagination-search.md

@@ -0,0 +1,185 @@
+# Pagination & search
+
+This example builds an articles listing endpoint that supports **offset pagination**, **cursor pagination**, **full-text search**, **faceted filtering**, and **sorting** — all from a single `CrudFactory` definition.
+
+## Models
+
+```python title="models.py"
+--8<-- "docs_src/examples/pagination_search/models.py"
+```
+
+## Schemas
+
+```python title="schemas.py"
+--8<-- "docs_src/examples/pagination_search/schemas.py"
+```
+
+## Crud
+
+Declare `searchable_fields`, `facet_fields`, and `order_fields` once on [`CrudFactory`](../reference/crud.md#fastapi_toolsets.crud.factory.CrudFactory). All endpoints built from this class share the same defaults and can override them per call.
+
+```python title="crud.py"
+--8<-- "docs_src/examples/pagination_search/crud.py"
+```
+
+## Session dependency
+
+```python title="db.py"
+--8<-- "docs_src/examples/pagination_search/db.py"
+```
+
+!!! info "Deploy a Postgres DB with docker"
+    ```bash
+    docker run -d --name postgres -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=postgres -p 5432:5432 postgres:18-alpine
+    ```
+
+
+## App
+
+```python title="app.py"
+--8<-- "docs_src/examples/pagination_search/app.py"
+```
+
+
+## Routes
+
+```python title="routes.py:1:16"
+--8<-- "docs_src/examples/pagination_search/routes.py:1:16"
+```
+
+### Offset pagination
+
+Best for admin panels or any UI that needs a total item count and numbered pages.
+
+```python title="routes.py:19:37"
+--8<-- "docs_src/examples/pagination_search/routes.py:19:37"
+```
+
+**Example request**
+
+```
+GET /articles/offset?page=2&items_per_page=10&search=fastapi&status=published&order_by=title&order=asc
+```
+
+**Example response**
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "offset",
+  "data": [
+    { "id": "3f47ac69-...", "title": "FastAPI tips", "status": "published", ... }
+  ],
+  "pagination": {
+    "total_count": 42,
+    "pages": 5,
+    "page": 2,
+    "items_per_page": 10,
+    "has_more": true
+  },
+  "filter_attributes": {
+    "status": ["archived", "draft", "published"],
+    "name": ["backend", "frontend", "python"]
+  }
+}
+```
+
+`filter_attributes` always reflects the values visible **after** applying the active filters. Use it to populate filter dropdowns on the client.
+
+To skip the `COUNT(*)` query for better performance on large tables, pass `include_total=False`. `pagination.total_count` will be `null` in the response, while `has_more` remains accurate.
+
+### Cursor pagination
+
+Best for feeds, infinite scroll, or any high-throughput API where offset performance degrades.
+
+```python title="routes.py:40:58"
+--8<-- "docs_src/examples/pagination_search/routes.py:40:58"
+```
+
+**Example request**
+
+```
+GET /articles/cursor?items_per_page=10&status=published&order_by=created_at&order=desc
+```
+
+**Example response**
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "cursor",
+  "data": [
+    { "id": "3f47ac69-...", "title": "FastAPI tips", "status": "published", ... }
+  ],
+  "pagination": {
+    "next_cursor": "eyJ2YWx1ZSI6ICIzZjQ3YWM2OS0uLi4ifQ==",
+    "prev_cursor": null,
+    "items_per_page": 10,
+    "has_more": true
+  },
+  "filter_attributes": {
+    "status": ["published"],
+    "name": ["backend", "python"]
+  }
+}
+```
+
+Pass `next_cursor` as the `cursor` query parameter on the next request to advance to the next page.
+
+### Unified endpoint (both strategies)
+
+!!! info "Added in `v2.3.0`"
+
+[`paginate()`](../module/crud.md#unified-endpoint-both-strategies) lets a single endpoint support both strategies via a `pagination_type` query parameter. The `pagination_type` field in the response acts as a discriminator for frontend tooling.
+
+```python title="routes.py:61:79"
+--8<-- "docs_src/examples/pagination_search/routes.py:61:79"
+```
+
+**Offset request** (default)
+
+```
+GET /articles/?pagination_type=offset&page=1&items_per_page=10
+```
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "offset",
+  "data": ["..."],
+  "pagination": { "total_count": 42, "pages": 5, "page": 1, "items_per_page": 10, "has_more": true }
+}
+```
+
+**Cursor request**
+
+```
+GET /articles/?pagination_type=cursor&items_per_page=10
+GET /articles/?pagination_type=cursor&items_per_page=10&cursor=eyJ2YWx1ZSI6...
+```
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "cursor",
+  "data": ["..."],
+  "pagination": { "next_cursor": "eyJ2YWx1ZSI6...", "prev_cursor": null, "items_per_page": 10, "has_more": true }
+}
+```
+
+## Search behaviour
+
+Both endpoints inherit the same `searchable_fields` declared on `ArticleCrud`:
+
+Search is **case-insensitive** and uses a `LIKE %query%` pattern. Pass a [`SearchConfig`](../reference/crud.md#fastapi_toolsets.crud.search.SearchConfig) instead of a plain string to control case sensitivity or switch to `match_mode="all"` (AND across all fields instead of OR).
+
+```python
+from fastapi_toolsets.crud import SearchConfig
+
+# Both title AND body must contain "fastapi"
+result = await ArticleCrud.offset_paginate(
+    session,
+    search=SearchConfig(query="fastapi", case_sensitive=True, match_mode="all"),
+    search_fields=[Article.title, Article.body],
+)
+```

docs/index.md

@@ -0,0 +1,69 @@
+# FastAPI Toolsets
+
+A modular collection of production-ready utilities for FastAPI. Install only what you need — from async CRUD and database helpers to CLI tooling, Prometheus metrics, and pytest fixtures. Each module is independently installable via optional extras, keeping your dependency footprint minimal.
+
+[![CI](https://github.com/d3vyce/fastapi-toolsets/actions/workflows/ci.yml/badge.svg)](https://github.com/d3vyce/fastapi-toolsets/actions/workflows/ci.yml)
+[![codecov](https://codecov.io/gh/d3vyce/fastapi-toolsets/graph/badge.svg)](https://codecov.io/gh/d3vyce/fastapi-toolsets)
+[![ty](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ty/main/assets/badge/v0.json)](https://github.com/astral-sh/ty)
+[![uv](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/uv/main/assets/badge/v0.json)](https://github.com/astral-sh/uv)
+[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)
+[![Python 3.11+](https://img.shields.io/badge/python-3.11+-blue.svg)](https://www.python.org/downloads/)
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+
+---
+
+**Documentation**: [https://fastapi-toolsets.d3vyce.fr](https://fastapi-toolsets.d3vyce.fr)
+
+**Source Code**: [https://github.com/d3vyce/fastapi-toolsets](https://github.com/d3vyce/fastapi-toolsets)
+
+---
+
+## Installation
+
+The base package includes the core modules (CRUD, database, schemas, exceptions, fixtures, dependencies, model mixins, logging):
+
+```bash
+uv add fastapi-toolsets
+```
+
+Install only the extras you need:
+
+```bash
+uv add "fastapi-toolsets[cli]"
+uv add "fastapi-toolsets[metrics]"
+uv add "fastapi-toolsets[pytest]"
+```
+
+Or install everything:
+
+```bash
+uv add "fastapi-toolsets[all]"
+```
+
+## Features
+
+### Core
+
+- **CRUD**: Generic async CRUD operations with `CrudFactory`, built-in full-text/faceted search and Offset/Cursor pagination.
+- **Database**: Session management, transaction helpers, table locking, and polling-based row change detection
+- **Dependencies**: FastAPI dependency factories (`PathDependency`, `BodyDependency`) for automatic DB lookups from path or body parameters
+- **Fixtures**: Fixture system with dependency management, context support, and pytest integration
+- **Model Mixins**: SQLAlchemy mixins for common column patterns (`UUIDMixin`, `UUIDv7Mixin`, `CreatedAtMixin`, `UpdatedAtMixin`, `TimestampMixin`).
+- **Lifecycle Events**: Post-commit event system (`EventSession`, `listens_for`) that dispatches async/sync callbacks for insert, update, and delete operations.
+- **Standardized API Responses**: Consistent response format with `Response`, `ErrorResponse`, `PaginatedResponse`, `CursorPaginatedResponse` and `OffsetPaginatedResponse`.
+- **Exception Handling**: Structured error responses with automatic OpenAPI documentation
+- **Logging**: Logging configuration with uvicorn integration via `configure_logging` and `get_logger`
+
+### Optional
+
+- **CLI**: Django-like command-line interface with fixture management and custom commands support
+- **Metrics**: Prometheus metrics endpoint with provider/collector registry
+- **Pytest Helpers**: Async test client, database session management, `pytest-xdist` support, and table cleanup utilities
+
+## License
+
+MIT License - see [LICENSE](LICENSE) for details.
+
+## Contributing
+
+Contributions are welcome! Please feel free to submit issues and pull requests.

docs/migration/v2.md

@@ -0,0 +1,144 @@
+# Migrating to v2.0
+
+This page covers every breaking change introduced in **v2.0** and the steps required to update your code.
+
+---
+
+## CRUD
+
+### `schema` is now required in `offset_paginate()` and `cursor_paginate()`
+
+Calls that omit `schema` will now raise a `TypeError` at runtime.
+
+Previously `schema` was optional; omitting it returned raw SQLAlchemy model instances inside the response. It is now a required keyword argument and the response always contains serialized schema instances.
+
+=== "Before (`v1`)"
+
+    ```python
+    # schema omitted — returned raw model instances
+    result = await UserCrud.offset_paginate(session=session, page=1)
+    result = await UserCrud.cursor_paginate(session=session, cursor=token)
+    ```
+
+=== "Now (`v2`)"
+
+    ```python
+    result = await UserCrud.offset_paginate(session=session, page=1, schema=UserRead)
+    result = await UserCrud.cursor_paginate(session=session, cursor=token, schema=UserRead)
+    ```
+
+### `as_response` removed from `create()`, `get()`, and `update()`
+
+Passing `as_response` to these methods will raise a `TypeError` at runtime.
+
+The `as_response=True` shorthand is replaced by passing a `schema` directly. The return value is a `Response[schema]` when `schema` is provided, or the raw model instance when it is not.
+
+=== "Before (`v1`)"
+
+    ```python
+    user = await UserCrud.create(session=session, obj=data, as_response=True)
+    user = await UserCrud.get(session=session, filters=filters, as_response=True)
+    user = await UserCrud.update(session=session, obj=data, filters, as_response=True)
+    ```
+
+=== "Now (`v2`)"
+
+    ```python
+    user = await UserCrud.create(session=session, obj=data, schema=UserRead)
+    user = await UserCrud.get(session=session, filters=filters, schema=UserRead)
+    user = await UserCrud.update(session=session, obj=data, filters, schema=UserRead)
+    ```
+
+### `delete()`: `as_response` renamed and return type changed
+
+`as_response` is gone, and the plain (non-response) call no longer returns `True`.
+
+Two changes were made to `delete()`:
+
+1. The `as_response` parameter is renamed to `return_response`.
+2. When called without `return_response=True`, the method now returns `None` on success instead of `True`.
+
+=== "Before (`v1`)"
+
+    ```python
+    ok = await UserCrud.delete(session=session, filters=filters)
+    if ok:  # True on success
+        ...
+
+    response = await UserCrud.delete(session=session, filters=filters, as_response=True)
+    ```
+
+=== "Now (`v2`)"
+
+    ```python
+    await UserCrud.delete(session=session, filters=filters)  # returns None
+
+    response = await UserCrud.delete(session=session, filters=filters, return_response=True)
+    ```
+
+### `paginate()` alias removed
+
+Any call to `crud.paginate(...)` will raise `AttributeError` at runtime.
+
+The `paginate` shorthand was an alias for `offset_paginate`. It has been removed; call `offset_paginate` directly.
+
+=== "Before (`v1`)"
+
+    ```python
+    result = await UserCrud.paginate(
+        session=session, page=2, items_per_page=20, schema=UserRead
+    )
+    ```
+
+=== "Now (`v2`)"
+
+    ```python
+    result = await UserCrud.offset_paginate(
+        session=session, page=2, items_per_page=20, schema=UserRead
+    )
+    ```
+
+---
+
+## Exceptions
+
+### Missing `api_error` raises `TypeError` at class definition time
+
+Unfinished or stub exception subclasses that previously compiled fine will now fail on import.
+
+In `v1`, a subclass without `api_error` would only fail when the exception was raised. In `v2`, `__init_subclass__` validates this at class definition time.
+
+=== "Before (`v1`)"
+
+    ```python
+    class MyError(ApiException):
+        pass  # fine until raised
+    ```
+
+=== "Now (`v2`)"
+
+    ```python
+    class MyError(ApiException):
+        pass  # TypeError: MyError must define an 'api_error' class attribute.
+    ```
+
+For shared base classes that are not meant to be raised directly, use `abstract=True`:
+
+```python
+class BillingError(ApiException, abstract=True):
+    """Base for all billing-related errors — not raised directly."""
+
+
+class PaymentRequiredError(BillingError):
+    api_error = ApiError(
+        code=402, msg="Payment Required", desc="...", err_code="BILLING-402"
+    )
+```
+
+---
+
+## Schemas
+
+### `Pagination` alias removed
+
+`Pagination` was already deprecated in `v1` and is fully removed in `v2`, you now need to use [`OffsetPagination`](../reference/schemas.md#fastapi_toolsets.schemas.OffsetPagination) or [`CursorPagination`](../reference/schemas.md#fastapi_toolsets.schemas.CursorPagination).

docs/migration/v3.md

@@ -0,0 +1,191 @@
+# Migrating to v3.0
+
+This page covers every breaking change introduced in **v3.0** and the steps required to update your code.
+
+---
+
+## CRUD
+
+### Facet keys now always use the full relationship chain
+
+In `v2`, relationship facet fields used only the terminal column key (e.g. `"name"` for `Role.name`) and only prepended the relationship name when two facet fields shared the same column key. In `v3`, facet keys **always** include the full relationship chain joined by `__`, regardless of collisions.
+
+=== "Before (`v2`)"
+
+    ```
+    User.status -> status
+    (User.role, Role.name) -> name
+    (User.role, Role.permission, Permission.name) -> name
+    ```
+
+=== "Now (`v3`)"
+
+    ```
+    User.status -> status
+    (User.role, Role.name) -> role__name
+    (User.role, Role.permission, Permission.name) -> role__permission__name
+    ```
+
+---
+
+### `*_params` dependencies consolidated into per-paginate methods
+
+The six individual dependency methods (`offset_params`, `cursor_params`, `paginate_params`, `filter_params`, `search_params`, `order_params`) have been **removed** and replaced by three consolidated methods that bundle pagination, search, filter, and order into a single `Depends()` call.
+
+| Removed | Replacement |
+|---|---|
+| `offset_params()` + `filter_params()` + `search_params()` + `order_params()` | `offset_paginate_params()` |
+| `cursor_params()` + `filter_params()` + `search_params()` + `order_params()` | `cursor_paginate_params()` |
+| `paginate_params()` + `filter_params()` + `search_params()` + `order_params()` | `paginate_params()` |
+
+Each new method accepts `search`, `filter`, and `order` boolean toggles (all `True` by default) to disable features you don't need.
+
+=== "Before (`v2`)"
+
+    ```python
+    from fastapi_toolsets.crud import OrderByClause
+
+
+    @router.get("/offset")
+    async def list_articles_offset(
+        session: SessionDep,
+        params: Annotated[dict, Depends(ArticleCrud.offset_params(default_page_size=20))],
+        filter_by: Annotated[dict, Depends(ArticleCrud.filter_params())],
+        order_by: Annotated[
+            OrderByClause | None,
+            Depends(ArticleCrud.order_params(default_field=Article.created_at)),
+        ],
+        search: str | None = None,
+    ) -> OffsetPaginatedResponse[ArticleRead]:
+        return await ArticleCrud.offset_paginate(
+            session=session,
+            **params,
+            search=search,
+            filter_by=filter_by or None,
+            order_by=order_by,
+            schema=ArticleRead,
+        )
+    ```
+
+=== "Now (`v3`)"
+
+    ```python
+    @router.get("/offset")
+    async def list_articles_offset(
+        session: SessionDep,
+        params: Annotated[
+            dict,
+            Depends(
+                ArticleCrud.offset_paginate_params(
+                    default_page_size=20,
+                    default_order_field=Article.created_at,
+                )
+            ),
+        ],
+    ) -> OffsetPaginatedResponse[ArticleRead]:
+        return await ArticleCrud.offset_paginate(
+            session=session, **params, schema=ArticleRead
+        )
+    ```
+
+The same pattern applies to `cursor_paginate_params()` and `paginate_params()`. To disable a feature, pass the toggle:
+
+```python
+# No search or ordering, only pagination + filtering
+ArticleCrud.offset_paginate_params(search=False, order=False)
+```
+
+---
+
+## Models
+
+The lifecycle event system has been rewritten. Callbacks are now registered with a module-level [`listens_for`](../reference/models.md#fastapi_toolsets.models.listens_for) decorator and dispatched by [`EventSession`](../reference/models.md#fastapi_toolsets.models.EventSession), replacing the mixin-based approach from `v2`.
+
+### `WatchedFieldsMixin` and `@watch` removed
+
+Importing `WatchedFieldsMixin` or `watch` will raise `ImportError`.
+
+Model method callbacks (`on_create`, `on_delete`, `on_update`) and the `@watch` decorator are replaced by:
+
+1. **`__watched_fields__`** — a plain class attribute to restrict which field changes trigger `UPDATE` events (replaces `@watch`).
+2. **`@listens_for`** — a module-level decorator to register callbacks for one or more [`ModelEvent`](../reference/models.md#fastapi_toolsets.models.ModelEvent) types (replaces `on_create` / `on_delete` / `on_update` methods).
+
+=== "Before (`v2`)"
+
+    ```python
+    from fastapi_toolsets.models import WatchedFieldsMixin, watch
+
+
+    @watch("status")
+    class Order(Base, UUIDMixin, WatchedFieldsMixin):
+        __tablename__ = "orders"
+
+        status: Mapped[str]
+
+        async def on_create(self):
+            await notify_new_order(self.id)
+
+        async def on_update(self, changes):
+            if "status" in changes:
+                await notify_status_change(self.id, changes["status"])
+
+        async def on_delete(self):
+            await notify_order_cancelled(self.id)
+    ```
+
+=== "Now (`v3`)"
+
+    ```python
+    from fastapi_toolsets.models import ModelEvent, UUIDMixin, listens_for
+
+
+    class Order(Base, UUIDMixin):
+        __tablename__ = "orders"
+        __watched_fields__ = ("status",)
+
+        status: Mapped[str]
+
+
+    @listens_for(Order, [ModelEvent.CREATE])
+    async def on_order_created(order: Order, event_type: ModelEvent, changes: None):
+        await notify_new_order(order.id)
+
+
+    @listens_for(Order, [ModelEvent.UPDATE])
+    async def on_order_updated(order: Order, event_type: ModelEvent, changes: dict):
+        if "status" in changes:
+            await notify_status_change(order.id, changes["status"])
+
+
+    @listens_for(Order, [ModelEvent.DELETE])
+    async def on_order_deleted(order: Order, event_type: ModelEvent, changes: None):
+        await notify_order_cancelled(order.id)
+    ```
+
+### `EventSession` now required
+
+Without `EventSession`, lifecycle callbacks will silently stop firing.
+
+Callbacks are now dispatched inside `EventSession.commit()` rather than via background tasks. Pass it as the session class when creating your session factory:
+
+=== "Before (`v2`)"
+
+    ```python
+    from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+
+    engine = create_async_engine("postgresql+asyncpg://...")
+    SessionLocal = async_sessionmaker(engine, expire_on_commit=False)
+    ```
+
+=== "Now (`v3`)"
+
+    ```python
+    from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+    from fastapi_toolsets.models import EventSession
+
+    engine = create_async_engine("postgresql+asyncpg://...")
+    SessionLocal = async_sessionmaker(engine, expire_on_commit=False, class_=EventSession)
+    ```
+
+!!! note
+    If you use `create_db_session` from `fastapi_toolsets.pytest`, the session already uses `EventSession` — no changes needed in tests.

docs/migration/v4.md

@@ -0,0 +1,42 @@
+# Migrating to v4.0
+
+This page covers every breaking change introduced in **v4.0** and the steps required to update your code.
+
+---
+
+## Database
+
+### `lock_tables` now takes a `session_maker` instead of a `session`
+
+The first argument of `lock_tables` changed from an `AsyncSession` instance to an `async_sessionmaker`.
+The function creates and manages its own **dedicated session** internally, yielding it to the caller.
+
+=== "Before (`v3`)"
+
+    ```python
+    from fastapi_toolsets.db import lock_tables, LockMode
+
+    async with lock_tables(session=session, tables=[User, Account]):
+        user = await UserCrud.get(session, [User.id == 1])
+        user.balance += 100
+
+    # With a custom lock mode
+    async with lock_tables(session=session, tables=[Order], mode=LockMode.EXCLUSIVE):
+        await process_order(session, order_id)
+    ```
+
+=== "Now (`v4`)"
+
+    ```python
+    from fastapi_toolsets.db import lock_tables, LockMode
+
+    async with lock_tables(session_maker=session_maker, tables=[User, Account]) as session:
+        user = await UserCrud.get(session, [User.id == 1])
+        user.balance += 100
+
+    # With a custom lock mode
+    async with lock_tables(
+        session_maker=session_maker, tables=[Order], mode=LockMode.EXCLUSIVE
+    ) as session:
+        await process_order(session, order_id)
+    ```

docs/migration/v5.md

@@ -0,0 +1,166 @@
+# Migrating to v5.0
+
+This page covers every breaking change introduced in **v5.0** and the steps required to update your code.
+
+---
+
+## Database
+
+`db.py` is now the `db/` package, built around one object, [`Database`](../reference/db.md#fastapi_toolsets.db.Database), that owns the engine and sessionmaker. The free functions that took a `session_maker` you built and passed around yourself are gone from request-handling code; `Database` builds the sessionmaker for you.
+
+### `create_db_dependency` / `create_db_context` removed in favor of `Database`
+
+Build one `Database` with your URL (or an existing `engine=`), then use the instance directly as the FastAPI dependency, and `db.session()` for sessions outside request handlers.
+
+=== "Before (`v4`)"
+
+    ```python
+    from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker
+    from fastapi_toolsets.db import create_db_dependency, create_db_context
+
+    engine = create_async_engine("postgresql+asyncpg://...")
+    SessionLocal = async_sessionmaker(engine, expire_on_commit=False)
+
+    get_db = create_db_dependency(session_maker=SessionLocal)
+    get_db_context = create_db_context(session_maker=SessionLocal)
+
+
+    @app.get("/users")
+    async def list_users(session: AsyncSession = Depends(get_db)): ...
+
+
+    async def seed():
+        async with get_db_context() as session:
+            ...
+    ```
+
+=== "Now (`v5`)"
+
+    ```python
+    from fastapi_toolsets.db import Database
+
+    db = Database(url="postgresql+asyncpg://...")
+
+
+    @app.get("/users")
+    async def list_users(session: AsyncSession = Depends(db)): ...
+
+
+    async def seed():
+        async with db.session() as session:
+            ...
+    ```
+
+Call `db.install(app)` to also commit before the response is sent (instead of in dependency teardown) and to dispose the engine on shutdown. See [the db module docs](../module/db.md#committing-before-the-response).
+
+### `get_transaction` renamed to `transaction`
+
+Same behavior (savepoint when already in a transaction, new transaction otherwise), new name, same import path.
+
+=== "Before (`v4`)"
+
+    ```python
+    from fastapi_toolsets.db import get_transaction
+
+    async with get_transaction(session=session):
+        session.add(model)
+    ```
+
+=== "Now (`v5`)"
+
+    ```python
+    from fastapi_toolsets.db import transaction
+
+    async with transaction(session=session):
+        session.add(model)
+    ```
+
+If you have a `Database` instance, `db.begin()` opens a session already inside a transaction:
+
+```python
+async with db.begin() as session:
+    session.add(User(name="ada"))
+```
+
+### `lock_tables` is now also a `Database` method
+
+The free `lock_tables(session_maker, tables, ...)` function still exists for callers who manage their own session factory, but prefer `db.lock_tables(tables, ...)`, which drops the `session_maker` argument:
+
+=== "Before (`v4`)"
+
+    ```python
+    from fastapi_toolsets.db import lock_tables, LockMode
+
+    async with lock_tables(
+        session_maker=session_maker, tables=[Order], mode=LockMode.EXCLUSIVE
+    ) as session:
+        await process_order(session, order_id)
+    ```
+
+=== "Now (`v5`)"
+
+    ```python
+    from fastapi_toolsets.db import LockMode
+
+    async with db.lock_tables(tables=[Order], mode=LockMode.EXCLUSIVE) as session:
+        await process_order(session, order_id)
+    ```
+
+### `create_database` and `cleanup_tables` moved to `fastapi_toolsets.db.testing`
+
+=== "Before (`v4`)"
+
+    ```python
+    from fastapi_toolsets.db import create_database, cleanup_tables
+    ```
+
+=== "Now (`v5`)"
+
+    ```python
+    from fastapi_toolsets.db.testing import create_database, cleanup_tables
+    ```
+
+## Fixtures
+
+### `get_obj_by_attr` / `get_field_by_attr` are now `FixtureRegistry` methods
+
+Both also change their first argument: instead of the fixture *function*, pass the fixture's *registered name* and let the registry look it up.
+
+=== "Before (`v4`)"
+
+    ```python
+    from fastapi_toolsets.fixtures import get_obj_by_attr, get_field_by_attr
+
+
+    @fixtures.register(depends_on=["roles"])
+    def users():
+        admin_role = get_obj_by_attr(fixtures=roles, attr_name="name", value="admin")
+        admin_role_id = get_field_by_attr(fixtures=roles, attr_name="name", value="admin")
+        return [User(id=1, username="alice", role_id=admin_role.id)]
+    ```
+
+=== "Now (`v5`)"
+
+    ```python
+    @fixtures.register(depends_on=["roles"])
+    def users():
+        admin_role = fixtures.obj(name="roles", attr_name="name", value="admin")
+        admin_role_id = fixtures.field(name="roles", attr_name="name", value="admin")
+        return [User(id=1, username="alice", role_id=admin_role.id)]
+    ```
+
+### Loading/listing by context now always includes `Context.BASE`
+
+`FixtureRegistry.get_variants`/`get_by_context`, `load_fixtures_by_context`, and the `fixtures list`/`fixtures load` CLI commands now implicitly union every queried context with `Context.BASE`. In `v4`, requesting a single context (e.g. `"testing"`) returned only fixtures tagged with that context; in `v5` it also returns every `Context.BASE`-tagged fixture.
+
+If you relied on strict exclusion of base fixtures, move them out of `Context.BASE` into their own context.
+
+### `load_fixtures` / `load_fixtures_by_context` now return reloaded instances
+
+Loaded objects are re-queried from the database after insert, with all relationships eager-loaded, instead of returning the exact objects your fixture function constructed. Code that compares returned objects by identity to the fixture function's output, or that expected relationships to remain unloaded, should be updated — and expect one extra query per model type per load.
+
+## Security
+
+The security module has been removed and moved to a dedicated python package: [`fastapi-multiauth`](https://github.com/d3vyce/fastapi-multiauth).
+
+Run `uv add fastapi-multiauth` and replace `from fastapi_toolsets.security import ...` with `from fastapi_multiauth import ...`.

docs/module/cli.md

@@ -0,0 +1,108 @@
+# CLI
+
+Typer-based command-line interface for managing your FastAPI application, with built-in fixture commands integration.
+
+## Installation
+
+=== "uv"
+    ``` bash
+    uv add "fastapi-toolsets[cli]"
+    ```
+
+=== "pip"
+    ``` bash
+    pip install "fastapi-toolsets[cli]"
+    ```
+
+## Overview
+
+The `cli` module provides a `manager` entry point built with [Typer](https://typer.tiangolo.com/). It allow custom commands to be added in addition of the fixture commands when a [`FixtureRegistry`](../reference/fixtures.md#fastapi_toolsets.fixtures.registry.FixtureRegistry) and a database context are configured.
+
+## Configuration
+
+Configure the CLI in your `pyproject.toml`:
+
+```toml
+[tool.fastapi-toolsets]
+custom_cli = "myapp.cli:cli"                   # Custom Typer app
+fixtures = "myapp.fixtures:registry"    # FixtureRegistry instance
+db_context = "myapp.db:db_context"      # Async context manager for sessions
+```
+
+All fields are optional. Without configuration, the `manager` command still works but no command are available.
+
+## Usage
+
+```bash
+# Manager commands
+manager --help
+
+ Usage: manager [OPTIONS] COMMAND [ARGS]...
+
+ FastAPI utilities CLI.
+
+╭─ Options ────────────────────────────────────────────────────────────────────────╮
+│ --install-completion          Install completion for the current shell.          │
+│ --show-completion             Show completion for the current shell, to copy it  │
+│                               or customize the installation.                     │
+│ --help                        Show this message and exit.                        │
+╰──────────────────────────────────────────────────────────────────────────────────╯
+╭─ Commands ───────────────────────────────────────────────────────────────────────╮
+│ check-db                                                                         │
+│ fixtures  Manage database fixtures.                                              │
+╰──────────────────────────────────────────────────────────────────────────────────╯
+
+# Fixtures commands
+manager fixtures --help
+
+ Usage: manager fixtures [OPTIONS] COMMAND [ARGS]...
+
+ Manage database fixtures.
+
+╭─ Options ────────────────────────────────────────────────────────────────────────╮
+│ --help          Show this message and exit.                                      │
+╰──────────────────────────────────────────────────────────────────────────────────╯
+╭─ Commands ───────────────────────────────────────────────────────────────────────╮
+│ list  List all registered fixtures.                                              │
+│ load  Load fixtures into the database.                                           │
+╰──────────────────────────────────────────────────────────────────────────────────╯
+```
+
+### `fixtures load`
+
+```bash
+manager fixtures load [CONTEXTS]... [--strategy merge|insert|skip_existing] [--dry-run]
+```
+
+`CONTEXTS` defaults to `Context.BASE` when omitted, and can also be set via the `FIXTURES_CONTEXT` environment variable, handy for CI/deploy scripts that shouldn't need an explicit argument per environment:
+
+```bash
+FIXTURES_CONTEXT=testing manager fixtures load
+```
+
+An explicit CLI argument always takes precedence over the environment variable.
+
+## Custom CLI
+
+You can extend the CLI by providing your own Typer app. The `manager` entry point will merge your app's commands with the built-in ones:
+
+```python
+# myapp/cli.py
+import typer
+
+cli = typer.Typer()
+
+
+@cli.command()
+def hello():
+    print("Hello from my app!")
+```
+
+```toml
+[tool.fastapi-toolsets]
+custom_cli = "myapp.cli:cli"
+```
+
+---
+
+[:material-api: API Reference](../reference/cli.md)

docs/module/crud.md

@@ -0,0 +1,705 @@
+# CRUD
+
+Generic async CRUD operations for SQLAlchemy models with search, pagination, and many-to-many support.
+
+!!! info
+    This module has been coded and tested to be compatible with PostgreSQL only.
+
+## Overview
+
+The `crud` module provides [`AsyncCrud`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud), a base class with a full suite of async database operations, and [`CrudFactory`](../reference/crud.md#fastapi_toolsets.crud.factory.CrudFactory), a convenience function to instantiate it for a given model.
+
+## Creating a CRUD class
+
+### Factory style
+
+```python
+from fastapi_toolsets.crud import CrudFactory
+from myapp.models import User
+
+UserCrud = CrudFactory(model=User)
+```
+
+[`CrudFactory`](../reference/crud.md#fastapi_toolsets.crud.factory.CrudFactory) dynamically creates a class named `AsyncUserCrud` with `User` as its model. This is the most concise option for straightforward CRUD with no custom logic.
+
+### Subclass style
+
+!!! info "Added in `v2.3.0`"
+
+```python
+from fastapi_toolsets.crud.factory import AsyncCrud
+from myapp.models import User
+
+
+class UserCrud(AsyncCrud[User]):
+    model = User
+    searchable_fields = [User.username, User.email]
+    default_load_options = [selectinload(User.role)]
+```
+
+Subclassing [`AsyncCrud`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud) directly is the preferred style when you need to add custom methods or when the configuration is complex enough to benefit from a named class body.
+
+### Adding custom methods
+
+```python
+class UserCrud(AsyncCrud[User]):
+    model = User
+
+    @classmethod
+    async def get_active(cls, session: AsyncSession) -> list[User]:
+        return await cls.get_multi(session, filters=[User.is_active == True])
+```
+
+### Sharing a custom base across multiple models
+
+Define a generic base class with the shared methods, then subclass it for each model:
+
+```python
+from typing import Generic, TypeVar
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase
+from fastapi_toolsets.crud.factory import AsyncCrud
+
+T = TypeVar("T", bound=DeclarativeBase)
+
+
+class AuditedCrud(AsyncCrud[T], Generic[T]):
+    """Base CRUD with custom function"""
+
+    @classmethod
+    async def get_active(cls, session: AsyncSession):
+        return await cls.get_multi(session, filters=[cls.model.is_active == True])
+
+
+class UserCrud(AuditedCrud[User]):
+    model = User
+    searchable_fields = [User.username, User.email]
+```
+
+You can also use the factory shorthand with the same base by passing `base_class`:
+
+```python
+UserCrud = CrudFactory(User, base_class=AuditedCrud)
+```
+
+## Basic operations
+
+!!! info "`get_or_none` added in `v2.2`"
+
+```python
+# Create
+user = await UserCrud.create(session=session, obj=UserCreateSchema(username="alice"))
+
+# Get one (raises NotFoundError if not found)
+user = await UserCrud.get(session=session, filters=[User.id == user_id])
+
+# Get one or None (never raises)
+user = await UserCrud.get_or_none(session=session, filters=[User.id == user_id])
+
+# Get first or None
+user = await UserCrud.first(session=session, filters=[User.email == email])
+
+# Get multiple
+users = await UserCrud.get_multi(session=session, filters=[User.is_active == True])
+
+# Update
+user = await UserCrud.update(
+    session=session, obj=UserUpdateSchema(username="bob"), filters=[User.id == user_id]
+)
+
+# Delete
+await UserCrud.delete(session=session, filters=[User.id == user_id])
+
+# Count / exists
+count = await UserCrud.count(session=session, filters=[User.is_active == True])
+exists = await UserCrud.exists(session=session, filters=[User.email == email])
+```
+
+## Fetching a single record
+
+Three methods fetch a single record — choose based on how you want to handle the "not found" case and whether you need strict uniqueness:
+
+| Method | Not found | Multiple results |
+|---|---|---|
+| `get` | raises `NotFoundError` | raises `MultipleResultsFound` |
+| `get_or_none` | returns `None` | raises `MultipleResultsFound` |
+| `first` | returns `None` | returns the first match silently |
+
+Use `get` when the record must exist (e.g. a detail endpoint that should return 404):
+
+```python
+user = await UserCrud.get(session=session, filters=[User.id == user_id])
+```
+
+Use `get_or_none` when the record may not exist but you still want strict uniqueness enforcement:
+
+```python
+user = await UserCrud.get_or_none(session=session, filters=[User.email == email])
+if user is None:
+    ...  # handle missing case without catching an exception
+```
+
+Use `first` when you only care about any one match and don't need uniqueness:
+
+```python
+user = await UserCrud.first(session=session, filters=[User.is_active == True])
+```
+
+## Row locking
+
+`get`, `get_or_none`, `first`, `get_multi`, and `update` all accept a `with_for_update` parameter that appends a `FOR UPDATE` clause to the underlying `SELECT`, preventing concurrent transactions from modifying the matched rows until the current transaction commits.
+
+| Value | SQL clause |
+|---|---|
+| `False` (default) | no locking |
+| `True` | `FOR UPDATE` |
+| `"nowait"` | `FOR UPDATE NOWAIT` |
+| `"skip_locked"` | `FOR UPDATE SKIP LOCKED` |
+
+```python
+# Lock before reading — typical read-modify-write pattern
+user = await UserCrud.get(session, [User.id == user_id], with_for_update=True)
+
+# Raise immediately if another transaction holds the lock
+user = await UserCrud.get(session, [User.id == user_id], with_for_update="nowait")
+
+# Skip rows already locked by another transaction (e.g. job queues)
+rows = await JobCrud.get_multi(
+    session, filters=[Job.status == "pending"], with_for_update="skip_locked"
+)
+
+# Lock atomically as part of update (prevents race between SELECT and UPDATE)
+user = await UserCrud.update(
+    session, UserUpdate(credits=10), [User.id == user_id], with_for_update=True
+)
+```
+
+!!! warning
+    `with_for_update` requires an open transaction. Wrap your call in `async with session.begin()` or use the `transaction` helper if you are not already inside one.
+
+!!! note
+    `NOWAIT` raises `sqlalchemy.exc.OperationalError` immediately if the row is locked rather than waiting.
+
+## Pagination
+
+!!! info "Added in `v1.1` (only offset_pagination via `paginate` if `<v1.1`)"
+
+Three pagination methods are available.  All return a typed response whose `pagination_type` field tells clients which strategy was used.
+
+| | `offset_paginate` | `cursor_paginate` | `paginate` |
+|---|---|---|---|
+| Return type | `OffsetPaginatedResponse` | `CursorPaginatedResponse` | either, based on `pagination_type` param |
+| Total count | Yes | No | / |
+| Jump to arbitrary page | Yes | No | / |
+| Performance on deep pages | Degrades | Constant | / |
+| Stable under concurrent inserts | No | Yes | / |
+| Use case | Admin panels, numbered pagination | Feeds, APIs, infinite scroll | single endpoint, both strategies |
+
+### Offset pagination
+
+```python
+from typing import Annotated
+from fastapi import Depends
+
+
+@router.get("")
+async def get_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.offset_paginate_params())],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, **params, schema=UserRead)
+```
+
+The [`offset_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.offset_paginate) method returns an [`OffsetPaginatedResponse`](../reference/schemas.md#fastapi_toolsets.schemas.OffsetPaginatedResponse):
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "offset",
+  "data": ["..."],
+  "pagination": {
+    "total_count": 100,
+    "pages": 5,
+    "page": 1,
+    "items_per_page": 20,
+    "has_more": true
+  }
+}
+```
+
+#### Skipping the COUNT query
+
+!!! info "Added in `v2.4.1`"
+
+By default `offset_paginate` runs two queries: one for the page items and one `COUNT(*)` for `total_count`. On large tables the `COUNT` can be expensive. Pass `include_total=False` to `offset_paginate_params()` to skip it:
+
+```python
+@router.get("")
+async def get_users(
+    session: SessionDep,
+    params: Annotated[
+        dict, Depends(UserCrud.offset_paginate_params(include_total=False))
+    ],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, **params, schema=UserRead)
+```
+
+### Cursor pagination
+
+```python
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.cursor_paginate_params())],
+) -> CursorPaginatedResponse[UserRead]:
+    return await UserCrud.cursor_paginate(session=session, **params, schema=UserRead)
+```
+
+The [`cursor_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.cursor_paginate) method returns a [`CursorPaginatedResponse`](../reference/schemas.md#fastapi_toolsets.schemas.CursorPaginatedResponse):
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "cursor",
+  "data": ["..."],
+  "pagination": {
+    "next_cursor": "eyJ2YWx1ZSI6ICIzZjQ3YWM2OS0uLi4ifQ==",
+    "prev_cursor": null,
+    "items_per_page": 20,
+    "has_more": true
+  }
+}
+```
+
+Pass `next_cursor` as the `cursor` query parameter on the next request to advance to the next page. `prev_cursor` is set on pages 2+ and points back to the first item of the current page. Both are `null` when there is no adjacent page.
+
+#### Choosing a cursor column
+
+The cursor column is set once on [`CrudFactory`](../reference/crud.md#fastapi_toolsets.crud.factory.CrudFactory) via the `cursor_column` parameter. It must be monotonically ordered for stable results:
+
+- Auto-increment integer PKs
+- UUID v7 PKs
+- Timestamps
+
+!!! warning
+    Random UUID v4 PKs are **not** suitable as cursor columns because their ordering is non-deterministic.
+
+!!! note
+    `cursor_column` is required. Calling [`cursor_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.cursor_paginate) on a CRUD class that has no `cursor_column` configured raises a `ValueError`.
+
+The cursor value is URL-safe base64-encoded (no padding) when returned to the client and decoded back to the correct Python type on the next request. The following SQLAlchemy column types are supported:
+
+| SQLAlchemy type | Python type |
+|---|---|
+| `Integer`, `BigInteger`, `SmallInteger` | `int` |
+| `Uuid` | `uuid.UUID` |
+| `DateTime` | `datetime.datetime` |
+| `Date` | `datetime.date` |
+| `Float`, `Numeric` | `decimal.Decimal` |
+
+```python
+# Paginate by the primary key
+PostCrud = CrudFactory(model=Post, cursor_column=Post.id)
+
+# Paginate by a timestamp column instead
+PostCrud = CrudFactory(model=Post, cursor_column=Post.created_at)
+```
+
+### Unified endpoint (both strategies)
+
+!!! info "Added in `v2.3.0`"
+
+[`paginate()`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.paginate) dispatches to `offset_paginate` or `cursor_paginate` based on a `pagination_type` query parameter, letting you expose **one endpoint** that supports both strategies.  The `pagination_type` field in the response tells clients which strategy was used, enabling frontend discriminated-union typing.
+
+```python
+from fastapi_toolsets.schemas import PaginatedResponse
+
+
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.paginate_params())],
+) -> PaginatedResponse[UserRead]:
+    return await UserCrud.paginate(session, **params, schema=UserRead)
+```
+
+```
+GET /users?pagination_type=offset&page=2&items_per_page=10
+GET /users?pagination_type=cursor&cursor=eyJ2YWx1ZSI6...&items_per_page=10
+```
+
+## Search
+
+Two search strategies are available, both compatible with [`offset_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.offset_paginate) and [`cursor_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.cursor_paginate).
+
+| | Full-text search | Faceted search |
+|---|---|---|
+| Input | Free-text string | Exact column values |
+| Relationship support | Yes | Yes |
+| Use case | Search bars | Filter dropdowns |
+
+!!! info "You can use both search strategies in the same endpoint!"
+
+### Full-text search
+
+!!! info "Added in `v2.2.1`"
+    The model's primary key is always included in `searchable_fields` automatically, so searching by ID works out of the box without any configuration. When no `searchable_fields` are declared, only the primary key is searched.
+
+Declare `searchable_fields` on the CRUD class. Relationship traversal is supported via tuples:
+
+```python
+PostCrud = CrudFactory(
+    model=Post,
+    searchable_fields=[
+        Post.title,
+        Post.content,
+        (Post.author, User.username),  # search across relationship
+    ],
+)
+```
+
+You can override `searchable_fields` per call with `search_fields`:
+
+```python
+result = await UserCrud.offset_paginate(
+    session=session,
+    search_fields=[User.country],
+)
+```
+
+Or via the dependency to narrow which fields are exposed as query parameters:
+
+```python
+params = UserCrud.offset_paginate_params(search_fields=[Post.title])
+```
+
+This allows searching with both [`offset_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.offset_paginate) and [`cursor_paginate`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.cursor_paginate):
+
+```python
+@router.get("")
+async def get_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.offset_paginate_params())],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, **params, schema=UserRead)
+```
+
+```python
+@router.get("")
+async def get_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.cursor_paginate_params())],
+) -> CursorPaginatedResponse[UserRead]:
+    return await UserCrud.cursor_paginate(session=session, **params, schema=UserRead)
+```
+
+The dependency adds two query parameters to the endpoint:
+
+| Parameter       | Type          |
+| --------------- | ------------- |
+| `search`        | `str \| null` |
+| `search_column` | `str \| null` |
+
+```
+GET /posts?search=hello                        → search all configured columns
+GET /posts?search=hello&search_column=title    → search only Post.title
+```
+
+The available search column keys are returned in the `search_columns` field of [`PaginatedResponse`](../reference/schemas.md#fastapi_toolsets.schemas.PaginatedResponse). Use them to populate a column picker in the UI, or to validate `search_column` values on the client side:
+
+```json
+{
+  "status": "SUCCESS",
+  "data": ["..."],
+  "pagination": { "..." },
+  "search_columns": ["content", "author__username", "title"]
+}
+```
+
+!!! info "Key format uses `__` as a separator for relationship chains."
+    A direct column `Post.title` produces `"title"`. A relationship tuple `(Post.author, User.username)` produces `"author__username"`. An unknown `search_column` value raises [`InvalidSearchColumnError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidSearchColumnError) (HTTP 422).
+
+### Faceted search
+
+!!! info "Added in `v1.2`"
+
+Declare `facet_fields` on the CRUD class to return distinct column values alongside paginated results. This is useful for populating filter dropdowns or building faceted search UIs. Relationship traversal is supported via tuples, using the same syntax as `searchable_fields`:
+
+```python
+UserCrud = CrudFactory(
+    model=User,
+    facet_fields=[
+        User.status,
+        User.country,
+        (User.role, Role.name),  # value from a related model
+    ],
+)
+```
+
+You can override `facet_fields` per call:
+
+```python
+result = await UserCrud.offset_paginate(
+    session=session,
+    facet_fields=[User.country],
+)
+```
+
+Or via the dependency to narrow which fields are exposed as query parameters:
+
+```python
+params = UserCrud.offset_paginate_params(facet_fields=[User.country])
+```
+
+Facet filtering is built into the consolidated params dependencies. When `filter=True` (the default), each facet field is exposed as a query parameter and values are collected into `filter_by` automatically:
+
+```python
+from typing import Annotated
+
+from fastapi import Depends
+
+
+@router.get("", response_model_exclude_none=True)
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.offset_paginate_params())],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, **params, schema=UserRead)
+```
+
+```python
+@router.get("", response_model_exclude_none=True)
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.cursor_paginate_params())],
+) -> CursorPaginatedResponse[UserRead]:
+    return await UserCrud.cursor_paginate(session=session, **params, schema=UserRead)
+```
+
+Both single-value and multi-value query parameters work:
+
+```
+GET /users?status=active                      → filter_by={"status": ["active"]}
+GET /users?status=active&country=FR           → filter_by={"status": ["active"], "country": ["FR"]}
+GET /users?role__name=admin&role__name=editor → filter_by={"role__name": ["admin", "editor"]}  (IN clause)
+```
+
+`filter_by` and `filters` can be combined — both are applied with AND logic.
+
+The distinct values for each facet field are returned in the `filter_attributes` field of [`PaginatedResponse`](../reference/schemas.md#fastapi_toolsets.schemas.PaginatedResponse). Use them to populate filter dropdowns in the UI, or to validate `filter_by` keys on the client side:
+
+```json
+{
+  "status": "SUCCESS",
+  "data": ["..."],
+  "pagination": { "..." },
+  "filter_attributes": {
+    "status": ["active", "inactive"],
+    "country": ["DE", "FR", "US"],
+    "role__name": ["admin", "editor", "viewer"]
+  }
+}
+```
+
+!!! info "Key format uses `__` as a separator for relationship chains."
+    A direct column `User.status` produces `"status"`. A relationship tuple `(User.role, Role.name)` produces `"role__name"`. A deeper chain `(User.role, Role.permission, Permission.name)` produces `"role__permission__name"`. An unknown `filter_by` key raises [`InvalidFacetFilterError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidFacetFilterError) (HTTP 422).
+
+#### Skipping facet queries
+
+!!! info "Added in `v5.1.0`"
+
+Facet values only change with the filters, not with the page. Pass `include_facets=False` to `offset_paginate_params()` / `cursor_paginate_params()` on pages 2..N to skip the facet queries entirely (`filter_attributes` will be `None`):
+
+```python
+params: Annotated[dict, Depends(UserCrud.offset_paginate_params(include_facets=False))]
+```
+
+## Sorting
+
+!!! info "Added in `v1.3`"
+
+Declare `order_fields` on the CRUD class. Relationship traversal is supported via tuples, using the same syntax as `searchable_fields` and `facet_fields`:
+
+```python
+UserCrud = CrudFactory(
+    model=User,
+    order_fields=[
+        User.name,
+        User.created_at,
+        (User.role, Role.name),  # sort by a related model column
+    ],
+)
+```
+
+You can override `order_fields` per call:
+
+```python
+result = await UserCrud.offset_paginate(
+    session=session,
+    order_fields=[User.name],
+)
+```
+
+Or via the dependency to narrow which fields are exposed as query parameters:
+
+```python
+params = UserCrud.offset_paginate_params(order_fields=[User.name])
+```
+
+Sorting is built into the consolidated params dependencies. When `order=True` (the default), `order_by` and `order` query parameters are exposed and resolved into an `OrderByClause` automatically:
+
+```python
+from typing import Annotated
+
+from fastapi import Depends
+
+
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.offset_paginate_params())],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, **params, schema=UserRead)
+```
+
+```python
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(UserCrud.cursor_paginate_params())],
+) -> CursorPaginatedResponse[UserRead]:
+    return await UserCrud.cursor_paginate(session=session, **params, schema=UserRead)
+```
+
+The dependency adds two query parameters to the endpoint:
+
+| Parameter  | Type            |
+| ---------- | --------------- |
+| `order_by` | `str \| null`  |
+| `order`    | `asc` or `desc` |
+
+```
+GET /users?order_by=name&order=asc         → ORDER BY users.name ASC
+GET /users?order_by=role__name&order=desc  → LEFT JOIN roles ON ... ORDER BY roles.name DESC
+```
+
+!!! info "Relationship tuples are joined automatically."
+    When a relation field is selected, the related table is LEFT OUTER JOINed automatically. An unknown `order_by` value raises [`InvalidOrderFieldError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidOrderFieldError) (HTTP 422).
+
+
+The available sort keys are returned in the `order_columns` field of [`PaginatedResponse`](../reference/schemas.md#fastapi_toolsets.schemas.PaginatedResponse). Use them to populate a sort picker in the UI, or to validate `order_by` values on the client side:
+
+```json
+{
+  "status": "SUCCESS",
+  "data": ["..."],
+  "pagination": { "..." },
+  "order_columns": ["created_at", "name", "role__name"]
+}
+```
+
+!!! info "Key format uses `__` as a separator for relationship chains."
+    A direct column `User.name` produces `"name"`. A relationship tuple `(User.role, Role.name)` produces `"role__name"`.
+
+## Relationship loading
+
+!!! info "Added in `v1.1`"
+
+By default, SQLAlchemy relationships are not loaded unless explicitly requested. Instead of using `lazy="selectin"` on model definitions (which is implicit and applies globally), define a `default_load_options` on the CRUD class to control loading strategy explicitly.
+
+!!! warning
+    Avoid using `lazy="selectin"` on model relationships. It fires silently on every query, cannot be disabled per-call, and can cause unexpected cascading loads through deep relationship chains. Use `default_load_options` instead.
+
+```python
+from sqlalchemy.orm import selectinload
+
+ArticleCrud = CrudFactory(
+    model=Article,
+    default_load_options=[
+        selectinload(Article.category),
+        selectinload(Article.tags),
+    ],
+)
+```
+
+`default_load_options` applies automatically to all read operations (`get`, `first`, `get_multi`, `offset_paginate`, `cursor_paginate`). When `load_options` is passed at call-site, it **fully replaces** `default_load_options` for that query — giving you precise per-call control:
+
+```python
+# Only loads category, tags are not loaded
+article = await ArticleCrud.get(
+    session=session,
+    filters=[Article.id == article_id],
+    load_options=[selectinload(Article.category)],
+)
+
+# Loads nothing — useful for write-then-refresh flows or lightweight checks
+articles = await ArticleCrud.get_multi(session=session, load_options=[])
+```
+
+## Many-to-many relationships
+
+Use `m2m_fields` to map schema fields containing lists of IDs to SQLAlchemy relationships. The CRUD class resolves and validates all IDs before persisting:
+
+```python
+PostCrud = CrudFactory(
+    model=Post,
+    m2m_fields={"tag_ids": Post.tags},
+)
+
+post = await PostCrud.create(
+    session=session, obj=PostCreateSchema(title="Hello", tag_ids=[1, 2, 3])
+)
+```
+
+## Upsert
+
+Atomic `INSERT ... ON CONFLICT DO UPDATE` using PostgreSQL:
+
+```python
+await UserCrud.upsert(
+    session=session,
+    obj=UserCreateSchema(email="alice@example.com", username="alice"),
+    index_elements=[User.email],
+    set_={"username"},
+)
+```
+
+## Response serialization
+
+!!! info "Added in `v1.1`"
+
+Pass a Pydantic schema class to `create`, `get`, `update`, or `offset_paginate` to serialize the result directly into that schema and wrap it in a [`Response[schema]`](../reference/schemas.md#fastapi_toolsets.schemas.Response) or [`PaginatedResponse[schema]`](../reference/schemas.md#fastapi_toolsets.schemas.PaginatedResponse):
+
+```python
+class UserRead(PydanticBase):
+    id: UUID
+    username: str
+
+
+@router.get(
+    "/{uuid}",
+    responses=generate_error_responses(NotFoundError),
+)
+async def get_user(session: SessionDep, uuid: UUID) -> Response[UserRead]:
+    return await crud.UserCrud.get(
+        session=session,
+        filters=[User.id == uuid],
+        schema=UserRead,
+    )
+
+
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    params: Annotated[dict, Depends(crud.UserCrud.offset_paginate_params())],
+) -> OffsetPaginatedResponse[UserRead]:
+    return await crud.UserCrud.offset_paginate(
+        session=session, **params, schema=UserRead
+    )
+```
+
+The schema must have `from_attributes=True` (or inherit from [`PydanticBase`](../reference/schemas.md#fastapi_toolsets.schemas.PydanticBase)) so it can be built from SQLAlchemy model instances.
+
+---
+
+[:material-api: API Reference](../reference/crud.md)

docs/module/db.md

@@ -0,0 +1,275 @@
+# DB
+
+SQLAlchemy async session management with transactions, table locking, advisory locking, and row-change polling.
+
+!!! info
+    This module has been coded and tested to be compatible with PostgreSQL only.
+
+## Overview
+
+The `db` module is built around one object, [`Database`](../reference/db.md#fastapi_toolsets.db.Database), which owns the engine and sessionmaker and exposes the FastAPI dependency, a commit-before-response middleware, session/transaction context managers, and table locking. Free helpers cover savepoint-aware transactions, advisory locks, many-to-many association tables, and row-change polling.
+
+## Setup
+
+Create one `Database` for your app. Provide a **URL** (the facade builds and disposes the engine) or pass an existing **`engine=`** you own (e.g. for Alembic or `event.listen`). The session factory is built internally with `expire_on_commit=False`.
+
+```python
+from fastapi import Depends, FastAPI
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from fastapi_toolsets.db import Database
+
+db = Database("postgresql+asyncpg://postgres:postgres@localhost/app")
+
+app = FastAPI()
+db.install(app)  # commit middleware + engine disposal on shutdown
+
+
+@app.get("/users")
+async def list_users(session: AsyncSession = Depends(db)): ...
+```
+
+The `Database` instance **is** the dependency: use it directly as `Depends(db)`. The whole request runs as a single transaction (CRUD writes use savepoints under it).
+
+The **URL** may be a plain string or a Pydantic [`PostgresDsn`](https://docs.pydantic.dev/latest/api/networks/#pydantic.networks.PostgresDsn). In URL mode you can tune the engine: pass `connect_args` for DBAPI-level options and any other keyword for `create_async_engine` (e.g. `pool_size`, `echo`, `pool_pre_ping`):
+
+```python
+from pydantic_settings import BaseSettings
+from pydantic import PostgresDsn
+
+
+class Settings(BaseSettings):
+    database_url: PostgresDsn
+
+
+settings = Settings()
+
+db = Database(
+    settings.database_url,
+    pool_size=20,
+    pool_pre_ping=True,
+    connect_args={"server_settings": {"application_name": "myapp"}},
+)
+```
+
+## Committing before the response
+
+[`db.install(app)`](../reference/db.md#fastapi_toolsets.db.Database) adds a middleware that commits the request's session when the response starts, after the endpoint returns and before the body is sent. With the middleware installed, the dependency does not commit again.
+
+The request is committed as a single transaction:
+
+- **Read-after-write**: a follow-up request sees the write.
+- **Atomicity**: multi-write endpoints roll back as a unit on failure.
+- **Errors roll back**: on a raised exception the session rolls back and nothing is committed.
+
+Without `install`, the session commits in the dependency teardown, which runs after the response has been sent.
+
+!!! warning "Streaming / SSE endpoints"
+    For a `StreamingResponse` / `EventSourceResponse`, the commit fires at the **start** of the stream. A stream that **writes** must open a short-lived session per write with [`db.session()`](#session-context-manager); the start-time commit will not flush writes made later during the stream.
+
+## Lifespan
+
+`db.install(app)` disposes the engine on shutdown, composing around your own lifespan:
+
+```python
+from contextlib import asynccontextmanager
+
+
+@asynccontextmanager
+async def lifespan(app):
+    await warm_cache()  # your startup
+    yield
+    await flush_metrics()  # your shutdown
+
+
+app = FastAPI(lifespan=lifespan)
+db.install(app)  # your shutdown runs first, then the engine is disposed
+```
+
+If you have no lifespan of your own, [`db.lifespan`](../reference/db.md#fastapi_toolsets.db.Database) works standalone as `FastAPI(lifespan=db.lifespan)`. Engine disposal is idempotent and is a no-op when you passed your own `engine=`.
+
+## Session context manager
+
+Use [`db.session()`](../reference/db.md#fastapi_toolsets.db.Database) for sessions outside request handlers (e.g. background tasks, CLI commands). It commits on clean exit and rolls back on exception:
+
+```python
+async def seed():
+    async with db.session() as session:
+        ...
+```
+
+## Transactions
+
+[`transaction`](../reference/db.md#fastapi_toolsets.db.transaction) opens a transaction on a session, using a savepoint when one is already open so it nests safely:
+
+```python
+from fastapi_toolsets.db import transaction
+
+
+async def create_user_with_role(session):
+    async with transaction(session):
+        ...
+        async with transaction(session):  # uses a savepoint
+            ...
+```
+
+When you have a `Database`, [`db.begin()`](../reference/db.md#fastapi_toolsets.db.Database) opens a session already inside a transaction:
+
+```python
+async with db.begin() as session:
+    session.add(User(name="ada"))  # commits on exit, rolls back on exception
+```
+
+## Table locking
+
+[`db.lock_tables`](../reference/db.md#fastapi_toolsets.db.Database) acquires PostgreSQL table-level locks for a critical section. It opens a dedicated session internally and releases the lock when the context exits:
+
+```python
+from fastapi_toolsets.db import LockMode
+
+async with db.lock_tables([User], mode=LockMode.EXCLUSIVE) as session:
+    # No other transaction can modify User until this block exits
+    ...
+```
+
+Available lock modes are defined in [`LockMode`](../reference/db.md#fastapi_toolsets.db.LockMode): `ACCESS_SHARE`, `ROW_SHARE`, `ROW_EXCLUSIVE`, `SHARE_UPDATE_EXCLUSIVE`, `SHARE`, `SHARE_ROW_EXCLUSIVE`, `EXCLUSIVE`, `ACCESS_EXCLUSIVE`.
+
+Pass `timeout` to limit how long the lock waits. On timeout, a [`LockTimeoutError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.LockTimeoutError) is raised instead of a raw database error:
+
+```python
+async with db.lock_tables([Order], timeout="2s") as session:
+    ...
+```
+
+## Advisory locking
+
+[`advisory_lock`](../reference/db.md#fastapi_toolsets.db.advisory_lock) acquires a PostgreSQL session-level advisory lock on a session you provide. The lock is released when the context exits:
+
+```python
+from fastapi_toolsets.db import advisory_lock
+
+# Blocking exclusive lock: waits until the lock is free
+async with advisory_lock(session=session, key=42):
+    ...
+
+# Non-blocking: yields False immediately if already held
+async with advisory_lock(session=session, key=42, nowait=True) as acquired:
+    if not acquired:
+        raise HTTPException(409, "Resource is locked")
+
+# Blocking with a timeout: raises LockTimeoutError if not acquired in time
+async with advisory_lock(session=session, key=42, timeout="5s"):
+    ...
+
+# Shared lock: multiple readers allowed simultaneously, blocks exclusive writers
+async with advisory_lock(session=session, key=42, shared=True):
+    ...
+
+# Two-integer key for namespacing (e.g. lock_type + resource_id)
+async with advisory_lock(session=session, key=(1, user_id)):
+    ...
+```
+
+!!! note
+    Advisory locks use PostgreSQL session-level functions (`pg_advisory_lock` / `pg_advisory_unlock`). The lock is tied to the database connection, not the SQLAlchemy transaction, so it is released when the context exits even if the surrounding transaction is still open.
+
+## Row-change polling
+
+[`wait_for_row_change`](../reference/db.md#fastapi_toolsets.db.wait_for_row_change) polls a row until a specific column changes value:
+
+```python
+from fastapi_toolsets.db import wait_for_row_change
+
+# Wait up to 30s for order.status to change
+await wait_for_row_change(
+    session=session,
+    model=Order,
+    pk_value=order_id,
+    columns=["status"],
+    interval=1.0,
+    timeout=30.0,
+)
+```
+
+## Creating a database
+
+[`create_database`](../reference/db.md#fastapi_toolsets.db.testing.create_database) (in `fastapi_toolsets.db.testing`) connects to *server_url* and issues a `CREATE DATABASE` statement:
+
+```python
+from fastapi_toolsets.db.testing import create_database
+
+SERVER_URL = "postgresql+asyncpg://postgres:postgres@localhost/postgres"
+
+await create_database(db_name="myapp_test", server_url=SERVER_URL)
+```
+
+For test isolation with automatic cleanup, use [`create_worker_database`](../reference/pytest.md#fastapi_toolsets.pytest.utils.create_worker_database) from the `pytest` module, which handles drop-before, create, and drop-after.
+
+## Cleaning up tables
+
+[`cleanup_tables`](../reference/db.md#fastapi_toolsets.db.testing.cleanup_tables) (in `fastapi_toolsets.db.testing`) truncates all tables:
+
+```python
+from fastapi_toolsets.db.testing import cleanup_tables
+
+
+@pytest.fixture(autouse=True)
+async def clean(db_session):
+    yield
+    await cleanup_tables(session=db_session, base=Base)
+```
+
+## Many-to-Many helpers
+
+The three `m2m_*` helpers modify a many-to-many association table with direct SQL, without loading the ORM collection.
+
+### `m2m_add`: insert associations
+
+[`m2m_add`](../reference/db.md#fastapi_toolsets.db.m2m_add) inserts one or more rows into a secondary table:
+
+```python
+from fastapi_toolsets.db import m2m_add
+
+async with db.lock_tables([Tag]) as session:
+    tag = await TagCrud.create(session, TagCreate(name="python"))
+    await m2m_add(session, post, Post.tags, tag)
+```
+
+Pass `ignore_conflicts=True` to skip associations that already exist:
+
+```python
+await m2m_add(session, post, Post.tags, tag, ignore_conflicts=True)
+```
+
+### `m2m_remove`: delete associations
+
+[`m2m_remove`](../reference/db.md#fastapi_toolsets.db.m2m_remove) deletes specific association rows. Removing a non-existent association is a no-op:
+
+```python
+from fastapi_toolsets.db import m2m_remove, transaction
+
+async with transaction(session):
+    await m2m_remove(session, post, Post.tags, tag1, tag2)
+```
+
+### `m2m_set`: replace the full set
+
+[`m2m_set`](../reference/db.md#fastapi_toolsets.db.m2m_set) replaces all associations: it deletes every existing row for the owner instance then inserts the new set. Passing no related instances clears the association:
+
+```python
+from fastapi_toolsets.db import m2m_set, transaction
+
+# Replace all tags
+async with transaction(session):
+    await m2m_set(session, post, Post.tags, tag_a, tag_b)
+
+# Clear all tags
+async with transaction(session):
+    await m2m_set(session, post, Post.tags)
+```
+
+All three helpers raise `TypeError` if the relationship attribute is not a Many-to-Many (i.e. has no secondary table).
+
+---
+
+[:material-api: API Reference](../reference/db.md)

docs/module/dependencies.md

@@ -0,0 +1,67 @@
+# Dependencies
+
+FastAPI dependency factories for automatic model resolution from path and body parameters.
+
+## Overview
+
+The `dependencies` module provides two factory functions that create FastAPI dependencies to fetch a model instance from the database automatically — either from a path parameter or from a request body field — and inject it directly into your route handler.
+
+## `PathDependency`
+
+[`PathDependency`](../reference/dependencies.md#fastapi_toolsets.dependencies.PathDependency) resolves a model from a URL path parameter and injects it into the route handler. Raises [`NotFoundError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.NotFoundError) automatically if the record does not exist.
+
+```python
+from fastapi_toolsets.dependencies import PathDependency
+
+# Plain callable
+UserDep = PathDependency(model=User, field=User.id, session_dep=get_db)
+
+# Annotated
+SessionDep = Annotated[AsyncSession, Depends(get_db)]
+UserDep = PathDependency(model=User, field=User.id, session_dep=SessionDep)
+
+
+@router.get("/users/{user_id}")
+async def get_user(user: User = UserDep):
+    return user
+```
+
+By default the parameter name is inferred from the field (`user_id` for `User.id`). You can override it:
+
+```python
+UserDep = PathDependency(model=User, field=User.id, session_dep=get_db, param_name="id")
+
+
+@router.get("/users/{id}")
+async def get_user(user: User = UserDep):
+    return user
+```
+
+## `BodyDependency`
+
+[`BodyDependency`](../reference/dependencies.md#fastapi_toolsets.dependencies.BodyDependency) resolves a model from a field in the request body. Useful when a body contains a foreign key and you want the full object injected:
+
+```python
+from fastapi_toolsets.dependencies import BodyDependency
+
+# Plain callable
+RoleDep = BodyDependency(
+    model=Role, field=Role.id, session_dep=get_db, body_field="role_id"
+)
+
+# Annotated
+SessionDep = Annotated[AsyncSession, Depends(get_db)]
+RoleDep = BodyDependency(
+    model=Role, field=Role.id, session_dep=SessionDep, body_field="role_id"
+)
+
+
+@router.post("/users")
+async def create_user(body: UserCreateSchema, role: Role = RoleDep):
+    user = User(username=body.username, role=role)
+    ...
+```
+
+---
+
+[:material-api: API Reference](../reference/dependencies.md)

docs/module/exceptions.md

@@ -0,0 +1,142 @@
+# Exceptions
+
+Structured API exceptions with consistent error responses and automatic OpenAPI documentation.
+
+## Overview
+
+The `exceptions` module provides a set of pre-built HTTP exceptions and a FastAPI exception handler that formats all errors — including validation errors — into a uniform [`ErrorResponse`](../reference/schemas.md#fastapi_toolsets.schemas.ErrorResponse).
+
+## Setup
+
+Register the exception handlers on your FastAPI app at startup:
+
+```python
+from fastapi import FastAPI
+from fastapi_toolsets.exceptions import init_exceptions_handlers
+
+app = FastAPI()
+init_exceptions_handlers(app=app)
+```
+
+This registers handlers for:
+
+- [`ApiException`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.ApiException) — all custom exceptions below
+- `HTTPException` — Starlette/FastAPI HTTP errors
+- `RequestValidationError` — Pydantic request validation (422)
+- `ResponseValidationError` — Pydantic response validation (422)
+- `Exception` — unhandled errors (500)
+
+It also patches `app.openapi()` to replace the default Pydantic 422 schema with a structured example matching the `ErrorResponse` format.
+
+## Built-in exceptions
+
+| Exception | Status | Default message |
+|-----------|--------|-----------------|
+| [`UnauthorizedError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.UnauthorizedError) | 401 | Unauthorized |
+| [`ForbiddenError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.ForbiddenError) | 403 | Forbidden |
+| [`NotFoundError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.NotFoundError) | 404 | Not Found |
+| [`ConflictError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.ConflictError) | 409 | Conflict |
+| [`NoSearchableFieldsError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.NoSearchableFieldsError) | 400 | No Searchable Fields |
+| [`InvalidFacetFilterError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidFacetFilterError) | 400 | Invalid Facet Filter |
+| [`InvalidOrderFieldError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidOrderFieldError) | 422 | Invalid Order Field |
+| [`PoolExhaustedError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.PoolExhaustedError) | 503 | Service Unavailable |
+| [`LockTimeoutError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.LockTimeoutError) | 503 | Service Unavailable |
+
+### Per-instance overrides
+
+All built-in exceptions accept optional keyword arguments to customise the response for a specific raise site without changing the class defaults:
+
+| Argument | Effect |
+|----------|--------|
+| `detail` | Overrides both `str(exc)` (log output) and the `message` field in the response body |
+| `desc` | Overrides the `description` field |
+| `data` | Overrides the `data` field |
+
+```python
+raise NotFoundError(
+    detail="User 42 not found", desc="No user with that ID exists in the database."
+)
+```
+
+## Custom exceptions
+
+Subclass [`ApiException`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.ApiException) and define an `api_error` class variable:
+
+```python
+from fastapi_toolsets.exceptions import ApiException
+from fastapi_toolsets.schemas import ApiError
+
+
+class PaymentRequiredError(ApiException):
+    api_error = ApiError(
+        code=402,
+        msg="Payment Required",
+        desc="Your subscription has expired.",
+        err_code="BILLING-402",
+    )
+```
+
+!!! warning
+    Subclasses that do not define `api_error` raise a `TypeError` at **class creation time**, not at raise time.
+
+### Custom `__init__`
+
+Override `__init__` to compute `detail`, `desc`, or `data` dynamically, then delegate to `super().__init__()`:
+
+```python
+class OrderValidationError(ApiException):
+    api_error = ApiError(
+        code=422,
+        msg="Order Validation Failed",
+        desc="One or more order fields are invalid.",
+        err_code="ORDER-422",
+    )
+
+    def __init__(self, *field_errors: str) -> None:
+        super().__init__(
+            f"{len(field_errors)} validation error(s)",
+            desc=", ".join(field_errors),
+            data={"errors": [{"message": e} for e in field_errors]},
+        )
+```
+
+### Intermediate base classes
+
+Use `abstract=True` when creating a shared base that is not meant to be raised directly:
+
+```python
+class BillingError(ApiException, abstract=True):
+    """Base for all billing-related errors."""
+
+
+class PaymentRequiredError(BillingError):
+    api_error = ApiError(
+        code=402, msg="Payment Required", desc="...", err_code="BILLING-402"
+    )
+
+
+class SubscriptionExpiredError(BillingError):
+    api_error = ApiError(
+        code=402, msg="Subscription Expired", desc="...", err_code="BILLING-402-EXP"
+    )
+```
+
+## OpenAPI response documentation
+
+Use [`generate_error_responses`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.generate_error_responses) to add error schemas to your endpoint's OpenAPI spec:
+
+```python
+from fastapi_toolsets.exceptions import generate_error_responses, NotFoundError, ForbiddenError
+
+@router.get(
+    "/users/{id}",
+    responses=generate_error_responses(NotFoundError, ForbiddenError),
+)
+async def get_user(...): ...
+```
+
+Multiple exceptions sharing the same HTTP status code are grouped under one entry, each appearing as a named example keyed by its `err_code`. This keeps the OpenAPI UI readable when several error variants map to the same status.
+
+---
+
+[:material-api: API Reference](../reference/exceptions.md)

docs/module/fixtures.md

@@ -0,0 +1,227 @@
+# Fixtures
+
+Dependency-aware database seeding with context-based loading strategies.
+
+## Overview
+
+The `fixtures` module lets you define named fixtures with dependencies between them, then load them into the database in the correct order. Fixtures can be scoped to contexts (e.g. base data, testing data) so that only the relevant ones are loaded for each environment.
+
+## Defining fixtures
+
+```python
+from fastapi_toolsets.fixtures import FixtureRegistry, Context
+
+fixtures = FixtureRegistry()
+
+
+@fixtures.register
+def roles():
+    return [
+        Role(id=1, name="admin"),
+        Role(id=2, name="user"),
+    ]
+
+
+@fixtures.register(depends_on=["roles"], contexts=[Context.TESTING])
+def test_users():
+    return [
+        User(id=1, username="alice", role_id=1),
+        User(id=2, username="bob", role_id=2),
+    ]
+```
+
+Dependencies declared via `depends_on` are resolved topologically — `roles` will always be loaded before `test_users`.
+
+## Loading fixtures
+
+By context with [`load_fixtures_by_context`](../reference/fixtures.md#fastapi_toolsets.fixtures.utils.load_fixtures_by_context):
+
+```python
+from fastapi_toolsets.fixtures import load_fixtures_by_context
+
+async with db_context() as session:
+    await load_fixtures_by_context(session, fixtures, Context.TESTING)
+```
+
+Directly by name with [`load_fixtures`](../reference/fixtures.md#fastapi_toolsets.fixtures.utils.load_fixtures):
+
+```python
+from fastapi_toolsets.fixtures import load_fixtures
+
+async with db_context() as session:
+    await load_fixtures(session, fixtures, "roles", "test_users")
+```
+
+Both functions return a `dict[str, list[...]]` mapping each fixture name to the list of loaded instances.
+
+## Contexts
+
+[`Context`](../reference/fixtures.md#fastapi_toolsets.fixtures.enum.Context) is an enum with predefined values:
+
+| Context | Description |
+|---------|-------------|
+| `Context.BASE` | Core data required in all environments |
+| `Context.TESTING` | Data only loaded during tests |
+| `Context.DEVELOPMENT` | Data only loaded in development |
+| `Context.PRODUCTION` | Data only loaded in production |
+
+A fixture with no `contexts` defined takes `Context.BASE` by default.
+
+`Context.BASE` fixtures are always included alongside whatever context you load or list — there's no way to load a non-base context in isolation:
+
+```python
+# also loads any Context.BASE fixtures, even though only TESTING is requested
+await load_fixtures_by_context(session, fixtures, Context.TESTING)
+```
+
+### Custom contexts
+
+Plain strings and any `Enum` subclass are accepted wherever a `Context` enum is expected.
+
+```python
+from enum import Enum
+
+
+class AppContext(str, Enum):
+    STAGING = "staging"
+    DEMO = "demo"
+
+
+@fixtures.register(contexts=[AppContext.STAGING])
+def staging_data():
+    return [Config(key="feature_x", enabled=True)]
+
+
+# loads staging_data plus any Context.BASE fixtures
+await load_fixtures_by_context(session, fixtures, AppContext.STAGING)
+```
+
+### Default context for a registry
+
+Pass `contexts` to `FixtureRegistry` to set a default for all fixtures registered in it:
+
+```python
+testing_registry = FixtureRegistry(contexts=[Context.TESTING])
+
+
+@testing_registry.register  # implicitly contexts=[Context.TESTING]
+def test_orders():
+    return [Order(id=1, total=99)]
+```
+
+### Same fixture name, multiple context variants
+
+The same fixture name may be registered under different (non-overlapping) context sets. When multiple contexts are loaded together, all matching variants are merged:
+
+```python
+@fixtures.register(contexts=[Context.BASE])
+def users():
+    return [User(id=1, username="admin")]
+
+
+@fixtures.register(contexts=[Context.TESTING])
+def users():
+    return [User(id=2, username="tester")]
+
+
+# loads both admin and tester (Context.BASE is included automatically)
+await load_fixtures_by_context(session, fixtures, Context.TESTING)
+```
+
+Registering two variants with overlapping context sets raises `ValueError`.
+
+## Load strategies
+
+[`LoadStrategy`](../reference/fixtures.md#fastapi_toolsets.fixtures.enum.LoadStrategy) controls how the fixture loader handles rows that already exist:
+
+| Strategy | Description |
+|----------|-------------|
+| `LoadStrategy.INSERT` | Insert only, fail on duplicates |
+| `LoadStrategy.MERGE` | Insert or update on conflict (default) |
+| `LoadStrategy.SKIP_EXISTING` | Skip rows that already exist |
+
+```python
+await load_fixtures_by_context(
+    session, fixtures, Context.BASE, strategy=LoadStrategy.SKIP_EXISTING
+)
+```
+
+## Merging registries
+
+Split fixture definitions across modules and merge them:
+
+```python
+from myapp.fixtures.dev import dev_fixtures
+from myapp.fixtures.prod import prod_fixtures
+
+fixtures = FixtureRegistry()
+fixtures.include_registry(registry=dev_fixtures)
+fixtures.include_registry(registry=prod_fixtures)
+```
+
+Fixtures with the same name are allowed as long as their context sets do not overlap. Conflicting contexts raise `ValueError`.
+
+## Looking up fixture instances
+
+[`FixtureRegistry.obj`](../reference/fixtures.md#fastapi_toolsets.fixtures.registry.FixtureRegistry.obj) retrieves a specific instance from a registered fixture by attribute value, looked up by name on the registry — useful when building cross-fixture `depends_on` relationships:
+
+```python
+@fixtures.register(depends_on=["roles"])
+def users():
+    admin_role = fixtures.obj("roles", "name", "admin")
+    return [User(id=1, username="alice", role_id=admin_role.id)]
+```
+
+Looking the fixture up by name (instead of importing the `roles` function directly) means fixture modules never need to import each other, which avoids circular imports in larger projects split across multiple files — the same reason `depends_on` takes fixture names rather than the functions themselves. The registry passed in must be the one that actually contains the fixture by load time; with a single shared registry this is automatic, but if you merge registries with `include_registry`, call `obj`/`field` on the merged registry.
+
+[`FixtureRegistry.field`](../reference/fixtures.md#fastapi_toolsets.fixtures.registry.FixtureRegistry.field) is shorthand for pulling a single attribute (`id` by default):
+
+```python
+@fixtures.register(depends_on=["roles"])
+def users():
+    return [
+        User(id=1, username="alice", role_id=fixtures.field("roles", "name", "admin"))
+    ]
+```
+
+Both raise `StopIteration` if no matching instance is found, and `KeyError` if the fixture name isn't registered.
+
+## Pytest integration
+
+Use [`register_fixtures`](../reference/pytest.md#fastapi_toolsets.pytest.plugin.register_fixtures) to expose each fixture in your registry as an injectable pytest fixture named `fixture_{name}` by default:
+
+```python
+# conftest.py
+import pytest
+from fastapi_toolsets.pytest import create_db_session, register_fixtures
+from app.fixtures import registry
+from app.models import Base
+
+DATABASE_URL = "postgresql+asyncpg://user:pass@localhost/test_db"
+
+
+@pytest.fixture
+async def db_session():
+    async with create_db_session(
+        database_url=DATABASE_URL, base=Base, cleanup=True
+    ) as session:
+        yield session
+
+
+register_fixtures(registry=registry, namespace=globals())
+```
+
+```python
+# test_users.py
+async def test_user_can_login(fixture_users: list[User], fixture_roles: list[Role]): ...
+```
+
+The load order is resolved automatically from the `depends_on` declarations in your registry. Each generated fixture receives `db_session` as a dependency and returns the list of loaded model instances.
+
+## CLI integration
+
+Fixtures can be triggered from the CLI. See the [CLI module](cli.md) for setup instructions.
+
+---
+
+[:material-api: API Reference](../reference/fixtures.md)

docs/module/logger.md

@@ -0,0 +1,39 @@
+# Logger
+
+Lightweight logging utilities with consistent formatting and uvicorn integration.
+
+## Overview
+
+The `logger` module provides two helpers: one to configure the root logger (and uvicorn loggers) at startup, and one to retrieve a named logger anywhere in your codebase.
+
+## Setup
+
+Call [`configure_logging`](../reference/logger.md#fastapi_toolsets.logger.configure_logging) once at application startup:
+
+```python
+from fastapi_toolsets.logger import configure_logging
+
+configure_logging(level="INFO")
+```
+
+This sets up a stdout handler with a consistent format and also configures uvicorn's access and error loggers so all log output shares the same style.
+
+## Getting a logger
+
+```python
+from fastapi_toolsets.logger import get_logger
+
+logger = get_logger(name=__name__)
+logger.info("User created")
+```
+
+When called without arguments, [`get_logger`](../reference/logger.md#fastapi_toolsets.logger.get_logger) auto-detects the caller's module name via frame inspection:
+
+```python
+# Equivalent to get_logger(name=__name__)
+logger = get_logger()
+```
+
+---
+
+[:material-api: API Reference](../reference/logger.md)

docs/module/metrics.md

@@ -0,0 +1,112 @@
+# Metrics
+
+Prometheus metrics integration with a decorator-based registry and multi-process support.
+
+## Installation
+
+=== "uv"
+    ``` bash
+    uv add "fastapi-toolsets[metrics]"
+    ```
+
+=== "pip"
+    ``` bash
+    pip install "fastapi-toolsets[metrics]"
+    ```
+
+## Overview
+
+The `metrics` module provides a [`MetricsRegistry`](../reference/metrics.md#fastapi_toolsets.metrics.registry.MetricsRegistry) to declare Prometheus metrics with decorators, and an [`init_metrics`](../reference/metrics.md#fastapi_toolsets.metrics.handler.init_metrics) function to mount a `/metrics` endpoint on your FastAPI app.
+
+## Setup
+
+```python
+from fastapi import FastAPI
+from fastapi_toolsets.metrics import MetricsRegistry, init_metrics
+
+app = FastAPI()
+metrics = MetricsRegistry()
+
+init_metrics(app=app, registry=metrics)
+```
+
+This mounts the `/metrics` endpoint that Prometheus can scrape.
+
+## Declaring metrics
+
+### Providers
+
+Providers are called once at startup by `init_metrics`. The return value (the Prometheus metric object) is stored in the registry and can be retrieved later with [`registry.get(name)`](../reference/metrics.md#fastapi_toolsets.metrics.registry.MetricsRegistry.get).
+
+Use providers when you want **deferred initialization**: the Prometheus metric is not registered with the global `CollectorRegistry` until `init_metrics` runs, not at import time. This is particularly useful for testing — importing the module in a test suite without calling `init_metrics` leaves no metrics registered, avoiding cross-test pollution.
+
+It is also useful when metrics are defined across multiple modules and merged with `include_registry`: any code that needs a metric can call `metrics.get()` on the shared registry instead of importing the metric directly from its origin module.
+
+If neither of these applies to you, declaring metrics at module level (e.g. `HTTP_REQUESTS = Counter(...)`) is simpler and equally valid.
+
+```python
+from prometheus_client import Counter, Histogram
+
+
+@metrics.register
+def http_requests():
+    return Counter("http_requests_total", "Total HTTP requests", ["method", "status"])
+
+
+@metrics.register
+def request_duration():
+    return Histogram("request_duration_seconds", "Request duration")
+```
+
+To use a provider's metric elsewhere (e.g. in a middleware), call `metrics.get()` inside the handler — **not** at module level, as providers are only initialized when `init_metrics` runs:
+
+```python
+async def metrics_middleware(request: Request, call_next):
+    response = await call_next(request)
+    metrics.get("http_requests").labels(
+        method=request.method, status=response.status_code
+    ).inc()
+    return response
+```
+
+### Collectors
+
+Collectors are called on every scrape. Use them for metrics that reflect current state (e.g. gauges).
+
+!!! warning "Declare the metric at module level"
+    Do **not** instantiate the Prometheus metric inside the collector function. Doing so recreates it on every scrape, raising `ValueError: Duplicated timeseries in CollectorRegistry`. Declare it once at module level instead:
+
+```python
+from prometheus_client import Gauge
+
+_queue_depth = Gauge("queue_depth", "Current queue depth")
+
+
+@metrics.register(collect=True)
+def collect_queue_depth():
+    _queue_depth.set(get_current_queue_depth())
+```
+
+## Merging registries
+
+Split metrics definitions across modules and merge them:
+
+```python
+from myapp.metrics.http import http_metrics
+from myapp.metrics.db import db_metrics
+
+metrics = MetricsRegistry()
+metrics.include_registry(registry=http_metrics)
+metrics.include_registry(registry=db_metrics)
+```
+
+## Multi-process mode
+
+Multi-process support is enabled automatically when the `PROMETHEUS_MULTIPROC_DIR` environment variable is set. No code changes are required.
+
+!!! warning "Environment variable name"
+    The correct variable is `PROMETHEUS_MULTIPROC_DIR` (not `PROMETHEUS_MULTIPROCESS_DIR`).
+
+---
+
+[:material-api: API Reference](../reference/metrics.md)

docs/module/models.md

@@ -0,0 +1,252 @@
+# Models
+
+!!! info "Added in `v2.0`"
+
+Reusable SQLAlchemy 2.0 mixins for common column patterns, designed to be composed freely on any `DeclarativeBase` model.
+
+## Overview
+
+The `models` module provides mixins that each add a single, well-defined column behaviour. They work with standard SQLAlchemy 2.0 declarative syntax and are fully compatible with `AsyncSession`.
+
+```python
+from fastapi_toolsets.models import UUIDMixin, TimestampMixin
+
+
+class Article(Base, UUIDMixin, TimestampMixin):
+    __tablename__ = "articles"
+
+    title: Mapped[str]
+    content: Mapped[str]
+```
+
+All timestamp columns are timezone-aware (`TIMESTAMPTZ`). All defaults are server-side (`clock_timestamp()`), so they are also applied when inserting rows via raw SQL outside the ORM.
+
+## Mixins
+
+### [`UUIDMixin`](../reference/models.md#fastapi_toolsets.models.UUIDMixin)
+
+Adds a `id: UUID` primary key generated server-side by PostgreSQL using `gen_random_uuid()`. The value is retrieved via `RETURNING` after insert, so it is available on the Python object immediately after `flush()`.
+
+!!! warning "Requires PostgreSQL 13+"
+
+```python
+from fastapi_toolsets.models import UUIDMixin
+
+
+class User(Base, UUIDMixin):
+    __tablename__ = "users"
+
+    username: Mapped[str]
+
+
+# id is None before flush
+user = User(username="alice")
+session.add(user)
+await session.flush()
+print(user.id)  # UUID('...')
+```
+
+### [`UUIDv7Mixin`](../reference/models.md#fastapi_toolsets.models.UUIDv7Mixin)
+
+!!! info "Added in `v2.3`"
+
+Adds a `id: UUID` primary key generated server-side by PostgreSQL using `uuidv7()`. It's a time-ordered UUID format that encodes a millisecond-precision timestamp in the most significant bits, making it naturally sortable and index-friendly.
+
+!!! warning "Requires PostgreSQL 18+"
+
+```python
+from fastapi_toolsets.models import UUIDv7Mixin
+
+
+class Event(Base, UUIDv7Mixin):
+    __tablename__ = "events"
+
+    name: Mapped[str]
+
+
+# id is None before flush
+event = Event(name="user.signup")
+session.add(event)
+await session.flush()
+print(event.id)  # UUID('019...')
+```
+
+### [`CreatedAtMixin`](../reference/models.md#fastapi_toolsets.models.CreatedAtMixin)
+
+Adds a `created_at: datetime` column set to `clock_timestamp()` on insert. The column has no `onupdate` hook — it is intentionally immutable after the row is created.
+
+```python
+from fastapi_toolsets.models import UUIDMixin, CreatedAtMixin
+
+
+class Order(Base, UUIDMixin, CreatedAtMixin):
+    __tablename__ = "orders"
+
+    total: Mapped[float]
+```
+
+### [`UpdatedAtMixin`](../reference/models.md#fastapi_toolsets.models.UpdatedAtMixin)
+
+Adds an `updated_at: datetime` column set to `clock_timestamp()` on insert and automatically updated to `clock_timestamp()` on every ORM-level update (via SQLAlchemy's `onupdate` hook).
+
+```python
+from fastapi_toolsets.models import UUIDMixin, UpdatedAtMixin
+
+
+class Post(Base, UUIDMixin, UpdatedAtMixin):
+    __tablename__ = "posts"
+
+    title: Mapped[str]
+
+
+post = Post(title="Hello")
+await session.flush()
+await session.refresh(post)
+
+post.title = "Hello World"
+await session.flush()
+await session.refresh(post)
+print(post.updated_at)
+```
+
+!!! note
+    `updated_at` is updated by SQLAlchemy at ORM flush time. If you update rows via raw SQL (e.g. `UPDATE posts SET ...`), the column will **not** be updated automatically — use a database trigger if you need that guarantee.
+
+### [`TimestampMixin`](../reference/models.md#fastapi_toolsets.models.TimestampMixin)
+
+Convenience mixin that combines [`CreatedAtMixin`](../reference/models.md#fastapi_toolsets.models.CreatedAtMixin) and [`UpdatedAtMixin`](../reference/models.md#fastapi_toolsets.models.UpdatedAtMixin). Equivalent to inheriting both.
+
+```python
+from fastapi_toolsets.models import UUIDMixin, TimestampMixin
+
+
+class Article(Base, UUIDMixin, TimestampMixin):
+    __tablename__ = "articles"
+
+    title: Mapped[str]
+```
+
+## Lifecycle events
+
+The event system provides lifecycle callbacks that fire **after commit**. If the transaction rolls back, no callback fires.
+
+### Setup
+
+Event dispatch requires [`EventSession`](../reference/models.md#fastapi_toolsets.models.EventSession). Pass it as the session class when creating your session factory:
+
+```python
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from fastapi_toolsets.models import EventSession
+
+engine = create_async_engine("postgresql+asyncpg://...")
+SessionLocal = async_sessionmaker(engine, expire_on_commit=False, class_=EventSession)
+```
+
+!!! info "Callbacks fire on `session.commit()` only — not on savepoints."
+    Savepoints created by [`transaction`](db.md) or `begin_nested()` do **not**
+    trigger callbacks. All events accumulated across flushes are dispatched once
+    when the outermost `commit()` is called.
+
+### Events
+
+Three event types are available, each corresponding to a [`ModelEvent`](../reference/models.md#fastapi_toolsets.models.ModelEvent) value:
+
+| Event | Trigger |
+|---|---|
+| `ModelEvent.CREATE` | After `INSERT` commit |
+| `ModelEvent.DELETE` | After `DELETE` commit |
+| `ModelEvent.UPDATE` | After `UPDATE` commit on a watched field |
+
+!!! warning "Callbacks fire only for ORM-level changes. Rows updated via raw SQL (`UPDATE ... SET ...`) are not detected."
+
+### Watched fields
+
+Set `__watched_fields__` on the model to restrict which field changes trigger `UPDATE` events. It must be a `tuple[str, ...]` — any other type raises `TypeError`:
+
+| Class attribute | `UPDATE` behaviour |
+|---|---|
+| `__watched_fields__ = ("status", "role")` | Only fires when `status` or `role` changes |
+| *(not set)* | Fires when **any** mapped field changes |
+
+`__watched_fields__` is inherited through the class hierarchy via normal Python MRO. A subclass can override it:
+
+```python
+class Order(Base, UUIDMixin):
+    __watched_fields__ = ("status",)
+    ...
+
+
+class UrgentOrder(Order):
+    # inherits __watched_fields__ = ("status",)
+    ...
+
+
+class PriorityOrder(Order):
+    __watched_fields__ = ("priority",)
+    # overrides parent — UPDATE fires only for priority changes
+    ...
+```
+
+### Registering handlers
+
+Register handlers with the [`listens_for`](../reference/models.md#fastapi_toolsets.models.listens_for) decorator. Every callback receives three arguments: the model instance, the [`ModelEvent`](../reference/models.md#fastapi_toolsets.models.ModelEvent) that triggered it, and a `changes` dict (`None` for `CREATE` and `DELETE`):
+
+```python
+from fastapi_toolsets.models import ModelEvent, UUIDMixin, listens_for
+
+
+class Order(Base, UUIDMixin):
+    __tablename__ = "orders"
+    __watched_fields__ = ("status",)
+
+    status: Mapped[str]
+
+
+@listens_for(Order, [ModelEvent.CREATE])
+async def on_order_created(order: Order, event_type: ModelEvent, changes: None):
+    await notify_new_order(order.id)
+
+
+@listens_for(Order, [ModelEvent.DELETE])
+async def on_order_deleted(order: Order, event_type: ModelEvent, changes: None):
+    await notify_order_cancelled(order.id)
+
+
+@listens_for(Order, [ModelEvent.UPDATE])
+async def on_order_updated(order: Order, event_type: ModelEvent, changes: dict):
+    if "status" in changes:
+        await notify_status_change(order.id, changes["status"])
+```
+
+Multiple handlers can be registered for the same model and event. Handlers registered on a parent class also fire for subclass instances.
+
+A single handler can listen for multiple events at once. When `event_types` is omitted, the handler fires for all events:
+
+```python
+@listens_for(Order, [ModelEvent.CREATE, ModelEvent.UPDATE])
+async def on_order_changed(order: Order, event_type: ModelEvent, changes: dict | None):
+    await invalidate_cache(order.id)
+
+
+@listens_for(Order)  # all events
+async def on_any_order_event(
+    order: Order, event_type: ModelEvent, changes: dict | None
+):
+    await audit_log(order.id, event_type)
+```
+
+### Field changes format
+
+The `changes` dict maps each watched field that changed to `{"old": ..., "new": ...}`. Only fields that actually changed are included. For `CREATE` and `DELETE` events, `changes` is `None`:
+
+```python
+# CREATE / DELETE → changes is None
+# status changed   → {"status": {"old": "pending", "new": "shipped"}}
+# two fields changed → {"status": {...}, "assigned_to": {...}}
+```
+
+!!! info "Multiple flushes in one transaction are merged: the earliest `old` and latest `new` are preserved, and `on_update` fires only once per commit."
+
+---
+
+[:material-api: API Reference](../reference/models.md)

docs/module/pytest.md

@@ -0,0 +1,132 @@
+# Pytest
+
+Testing helpers for FastAPI applications: async HTTP client, database sessions, and parallel worker support.
+
+## Installation
+
+=== "uv"
+    ``` bash
+    uv add "fastapi-toolsets[pytest]"
+    ```
+
+=== "pip"
+    ``` bash
+    pip install "fastapi-toolsets[pytest]"
+    ```
+
+## Async client
+
+Use [`create_async_client`](../reference/pytest.md#fastapi_toolsets.pytest.utils.create_async_client) to get an `httpx.AsyncClient` bound to your FastAPI app:
+
+```python
+from fastapi_toolsets.pytest import create_async_client
+
+
+@pytest.fixture
+async def http_client(db_session):
+    async def _override_get_db():
+        yield db_session
+
+    async with create_async_client(
+        app=app,
+        base_url="http://127.0.0.1/api/v1",
+        dependency_overrides={get_db: _override_get_db},
+    ) as c:
+        yield c
+```
+
+Any extra keyword arguments are forwarded to `httpx.AsyncClient`, so you can set default headers, authentication, timeouts, and more:
+
+```python
+async with create_async_client(
+    app=app,
+    headers={"X-Api-Key": "secret"},
+    timeout=10,
+) as c:
+    ...
+```
+
+## Database sessions
+
+Use [`create_worker_database`](../reference/pytest.md#fastapi_toolsets.pytest.utils.create_worker_database) + [`create_db_session`](../reference/pytest.md#fastapi_toolsets.pytest.utils.create_db_session) to get a fully isolated `AsyncSession` for each test:
+
+```python
+from fastapi_toolsets.pytest import create_worker_database, create_db_session
+
+
+@pytest.fixture(scope="session")
+async def worker_db_url():
+    async with create_worker_database(
+        database_url=str(settings.SQLALCHEMY_DATABASE_URI)
+    ) as url:
+        yield url
+
+
+@pytest.fixture
+async def db_session(worker_db_url):
+    async with create_db_session(
+        database_url=worker_db_url, base=Base, cleanup=True
+    ) as session:
+        yield session
+```
+
+`create_worker_database` connects without specifying a database (asyncpg falls back to the username), so the target test database does not need to exist beforehand.
+
+!!! info
+    `cleanup=True` truncates all tables between tests via `TRUNCATE … RESTART IDENTITY CASCADE`, which is faster than dropping and recreating tables.
+
+### Engine and session options
+
+Pass `engine_kwargs` or `session_kwargs` to forward options to the underlying SQLAlchemy primitives:
+
+```python
+async with create_db_session(
+    database_url=worker_db_url,
+    base=Base,
+    engine_kwargs={"pool_size": 5, "connect_args": {"timeout": 10}},
+    session_kwargs={"autoflush": False},
+) as session:
+    ...
+```
+
+## Parallel testing with pytest-xdist
+
+The fixtures above work with `pytest-xdist` out of the box. Each worker gets its own database named after the worker (e.g. `gw0`, `gw1`). Pass `prefix` to namespace the database (e.g. `prefix="myapp"` → `myapp_gw0`).
+
+Use [`worker_database_url`](../reference/pytest.md#fastapi_toolsets.pytest.utils.worker_database_url) to derive the per-worker URL manually if needed:
+
+```python
+from fastapi_toolsets.pytest import worker_database_url
+
+url = worker_database_url(
+    "postgresql+asyncpg://user:pass@localhost/myapp", default_test_db="test"
+)
+# → "postgresql+asyncpg://user:pass@localhost/gw0" under xdist
+# → "postgresql+asyncpg://user:pass@localhost/test" otherwise
+
+url = worker_database_url(
+    "postgresql+asyncpg://user:pass@localhost/myapp",
+    default_test_db="test",
+    prefix="myapp",
+)
+# → "postgresql+asyncpg://user:pass@localhost/myapp_gw0" under xdist
+# → "postgresql+asyncpg://user:pass@localhost/myapp_test" otherwise
+```
+
+## Manual table cleanup
+
+[`cleanup_tables`](../reference/db.md#fastapi_toolsets.db.testing.cleanup_tables) truncates all tables in a single statement and can be called directly when you need more control:
+
+```python
+from fastapi_toolsets.pytest import cleanup_tables
+
+
+@pytest.fixture(autouse=True)
+async def clean(db_session):
+    yield
+    await cleanup_tables(session=db_session, base=Base)
+```
+
+---
+
+[:material-api: API Reference](../reference/pytest.md)

docs/module/schemas.md

@@ -0,0 +1,144 @@
+# Schemas
+
+Standardized Pydantic response models for consistent API responses across your FastAPI application.
+
+## Overview
+
+The `schemas` module provides generic response wrappers that enforce a uniform response structure. All models use `from_attributes=True` for ORM compatibility and `validate_assignment=True` for runtime type safety.
+
+## Response models
+
+### [`Response[T]`](../reference/schemas.md#fastapi_toolsets.schemas.Response)
+
+The most common wrapper for a single resource response.
+
+```python
+from fastapi_toolsets.schemas import Response
+
+
+@router.get("/users/{id}")
+async def get_user(user: User = UserDep) -> Response[UserSchema]:
+    return Response(data=user, message="User retrieved")
+```
+
+### Paginated response models
+
+Three classes wrap paginated list results. Pick the one that matches your endpoint's strategy:
+
+| Class | `pagination` type | `pagination_type` field | Use when |
+|---|---|---|---|
+| [`OffsetPaginatedResponse[T]`](#offsetpaginatedresponset) | `OffsetPagination` | `"offset"` (fixed) | endpoint always uses offset |
+| [`CursorPaginatedResponse[T]`](#cursorpaginatedresponset) | `CursorPagination` | `"cursor"` (fixed) | endpoint always uses cursor |
+| [`PaginatedResponse[T]`](#paginatedresponset) | `OffsetPagination \| CursorPagination` | — | unified endpoint supporting both strategies |
+
+#### [`OffsetPaginatedResponse[T]`](../reference/schemas.md#fastapi_toolsets.schemas.OffsetPaginatedResponse)
+
+!!! info "Added in `v2.3.0`"
+
+Use as the return type when the endpoint always uses [`offset_paginate`](crud.md#offset-pagination).  The `pagination` field is guaranteed to be an [`OffsetPagination`](../reference/schemas.md#fastapi_toolsets.schemas.OffsetPagination) object; the response always includes a `pagination_type: "offset"` discriminator.
+
+```python
+from fastapi_toolsets.schemas import OffsetPaginatedResponse
+
+
+@router.get("/users")
+async def list_users(
+    page: int = 1,
+    items_per_page: int = 20,
+) -> OffsetPaginatedResponse[UserSchema]:
+    return await UserCrud.offset_paginate(
+        session, page=page, items_per_page=items_per_page, schema=UserSchema
+    )
+```
+
+**Response shape:**
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "offset",
+  "data": ["..."],
+  "pagination": {
+    "total_count": 100,
+    "page": 1,
+    "items_per_page": 20,
+    "has_more": true
+  }
+}
+```
+
+#### [`CursorPaginatedResponse[T]`](../reference/schemas.md#fastapi_toolsets.schemas.CursorPaginatedResponse)
+
+!!! info "Added in `v2.3.0`"
+
+Use as the return type when the endpoint always uses [`cursor_paginate`](crud.md#cursor-pagination).  The `pagination` field is guaranteed to be a [`CursorPagination`](../reference/schemas.md#fastapi_toolsets.schemas.CursorPagination) object; the response always includes a `pagination_type: "cursor"` discriminator.
+
+```python
+from fastapi_toolsets.schemas import CursorPaginatedResponse
+
+
+@router.get("/events")
+async def list_events(
+    cursor: str | None = None,
+    items_per_page: int = 20,
+) -> CursorPaginatedResponse[EventSchema]:
+    return await EventCrud.cursor_paginate(
+        session, cursor=cursor, items_per_page=items_per_page, schema=EventSchema
+    )
+```
+
+**Response shape:**
+
+```json
+{
+  "status": "SUCCESS",
+  "pagination_type": "cursor",
+  "data": ["..."],
+  "pagination": {
+    "next_cursor": "eyJpZCI6IDQyfQ==",
+    "prev_cursor": null,
+    "items_per_page": 20,
+    "has_more": true
+  }
+}
+```
+
+#### [`PaginatedResponse[T]`](../reference/schemas.md#fastapi_toolsets.schemas.PaginatedResponse)
+
+Return type for endpoints that support **both** pagination strategies via a `pagination_type` query parameter (using [`paginate()`](crud.md#unified-endpoint-both-strategies)).
+
+When used as a return annotation, `PaginatedResponse[T]` automatically expands to `Annotated[Union[CursorPaginatedResponse[T], OffsetPaginatedResponse[T]], Field(discriminator="pagination_type")]`, so FastAPI emits a proper `oneOf` + discriminator in the OpenAPI schema with no extra boilerplate:
+
+```python
+from fastapi_toolsets.crud import PaginationType
+from fastapi_toolsets.schemas import PaginatedResponse
+
+
+@router.get("/users")
+async def list_users(
+    pagination_type: PaginationType = PaginationType.OFFSET,
+    page: int = 1,
+    cursor: str | None = None,
+    items_per_page: int = 20,
+) -> PaginatedResponse[UserSchema]:
+    return await UserCrud.paginate(
+        session,
+        pagination_type=pagination_type,
+        page=page,
+        cursor=cursor,
+        items_per_page=items_per_page,
+        schema=UserSchema,
+    )
+```
+
+#### Pagination metadata models
+
+The optional `filter_attributes` field is populated when `facet_fields` are configured on the CRUD class (see [Filter attributes](crud.md#faceted-search)). It is `None` by default and can be hidden from API responses with `response_model_exclude_none=True`.
+
+### [`ErrorResponse`](../reference/schemas.md#fastapi_toolsets.schemas.ErrorResponse)
+
+Returned automatically by the exceptions handler.
+
+---
+
+[:material-api: API Reference](../reference/schemas.md)

docs/reference/cli.md

@@ -0,0 +1,27 @@
+# `cli`
+
+Here's the reference for the CLI configuration helpers used to load settings from `pyproject.toml`.
+
+You can import them directly from `fastapi_toolsets.cli.config`:
+
+```python
+from fastapi_toolsets.cli.config import (
+    import_from_string,
+    get_config_value,
+    get_fixtures_registry,
+    get_db_context,
+    get_custom_cli,
+)
+```
+
+## ::: fastapi_toolsets.cli.config.import_from_string
+
+## ::: fastapi_toolsets.cli.config.get_config_value
+
+## ::: fastapi_toolsets.cli.config.get_fixtures_registry
+
+## ::: fastapi_toolsets.cli.config.get_db_context
+
+## ::: fastapi_toolsets.cli.config.get_custom_cli
+
+## ::: fastapi_toolsets.cli.utils.async_command

docs/reference/crud.md

@@ -0,0 +1,24 @@
+# `crud`
+
+Here's the reference for the CRUD classes, factory, and search utilities.
+
+You can import the main symbols from `fastapi_toolsets.crud`:
+
+```python
+from fastapi_toolsets.crud import CrudFactory, AsyncCrud
+from fastapi_toolsets.crud.search import (
+    SearchConfig,
+    get_searchable_fields,
+    build_search_filters,
+)
+```
+
+## ::: fastapi_toolsets.crud.factory.AsyncCrud
+
+## ::: fastapi_toolsets.crud.factory.CrudFactory
+
+## ::: fastapi_toolsets.crud.search.SearchConfig
+
+## ::: fastapi_toolsets.crud.search.get_searchable_fields
+
+## ::: fastapi_toolsets.crud.search.build_search_filters

docs/reference/db.md

@@ -0,0 +1,48 @@
+# `db`
+
+Here's the reference for the `Database` facade, the transaction helper, locking
+functions, many-to-many helpers, and row-watching utilities.
+
+You can import them directly from `fastapi_toolsets.db`:
+
+```python
+from fastapi_toolsets.db import (
+    Database,
+    LockMode,
+    advisory_lock,
+    lock_tables,
+    m2m_add,
+    m2m_remove,
+    m2m_set,
+    transaction,
+    wait_for_row_change,
+)
+```
+
+## ::: fastapi_toolsets.db.Database
+
+## ::: fastapi_toolsets.db.transaction
+
+## ::: fastapi_toolsets.db.LockMode
+
+## ::: fastapi_toolsets.db.lock_tables
+
+## ::: fastapi_toolsets.db.advisory_lock
+
+## ::: fastapi_toolsets.db.m2m_add
+
+## ::: fastapi_toolsets.db.m2m_remove
+
+## ::: fastapi_toolsets.db.m2m_set
+
+## ::: fastapi_toolsets.db.wait_for_row_change
+
+Admin and test helpers live in `fastapi_toolsets.db.testing`:
+
+```python
+from fastapi_toolsets.db.testing import cleanup_tables, create_database
+```
+
+## ::: fastapi_toolsets.db.testing.create_database
+
+## ::: fastapi_toolsets.db.testing.cleanup_tables

docs/reference/dependencies.md

@@ -0,0 +1,13 @@
+# `dependencies`
+
+Here's the reference for the FastAPI dependency factory functions.
+
+You can import them directly from `fastapi_toolsets.dependencies`:
+
+```python
+from fastapi_toolsets.dependencies import PathDependency, BodyDependency
+```
+
+## ::: fastapi_toolsets.dependencies.PathDependency
+
+## ::: fastapi_toolsets.dependencies.BodyDependency

docs/reference/exceptions.md

@@ -0,0 +1,49 @@
+# `exceptions`
+
+Here's the reference for all exception classes and handler utilities.
+
+You can import them directly from `fastapi_toolsets.exceptions`:
+
+```python
+from fastapi_toolsets.exceptions import (
+    ApiException,
+    UnauthorizedError,
+    ForbiddenError,
+    NotFoundError,
+    ConflictError,
+    NoSearchableFieldsError,
+    InvalidSearchColumnError,
+    InvalidFacetFilterError,
+    InvalidOrderFieldError,
+    PoolExhaustedError,
+    LockTimeoutError,
+    generate_error_responses,
+    init_exceptions_handlers,
+)
+```
+
+## ::: fastapi_toolsets.exceptions.exceptions.ApiException
+
+## ::: fastapi_toolsets.exceptions.exceptions.UnauthorizedError
+
+## ::: fastapi_toolsets.exceptions.exceptions.ForbiddenError
+
+## ::: fastapi_toolsets.exceptions.exceptions.NotFoundError
+
+## ::: fastapi_toolsets.exceptions.exceptions.ConflictError
+
+## ::: fastapi_toolsets.exceptions.exceptions.NoSearchableFieldsError
+
+## ::: fastapi_toolsets.exceptions.exceptions.InvalidSearchColumnError
+
+## ::: fastapi_toolsets.exceptions.exceptions.InvalidFacetFilterError
+
+## ::: fastapi_toolsets.exceptions.exceptions.InvalidOrderFieldError
+
+## ::: fastapi_toolsets.exceptions.exceptions.PoolExhaustedError
+
+## ::: fastapi_toolsets.exceptions.exceptions.LockTimeoutError
+
+## ::: fastapi_toolsets.exceptions.exceptions.generate_error_responses
+
+## ::: fastapi_toolsets.exceptions.handler.init_exceptions_handlers

docs/reference/fixtures.md

@@ -0,0 +1,28 @@
+# `fixtures`
+
+Here's the reference for the fixture registry, enums, and loading utilities.
+
+You can import them directly from `fastapi_toolsets.fixtures`:
+
+```python
+from fastapi_toolsets.fixtures import (
+    Context,
+    LoadStrategy,
+    Fixture,
+    FixtureRegistry,
+    load_fixtures,
+    load_fixtures_by_context,
+)
+```
+
+## ::: fastapi_toolsets.fixtures.enum.Context
+
+## ::: fastapi_toolsets.fixtures.enum.LoadStrategy
+
+## ::: fastapi_toolsets.fixtures.registry.Fixture
+
+## ::: fastapi_toolsets.fixtures.registry.FixtureRegistry
+
+## ::: fastapi_toolsets.fixtures.utils.load_fixtures
+
+## ::: fastapi_toolsets.fixtures.utils.load_fixtures_by_context

docs/reference/logger.md

@@ -0,0 +1,13 @@
+# `logger`
+
+Here's the reference for the logging utilities.
+
+You can import them directly from `fastapi_toolsets.logger`:
+
+```python
+from fastapi_toolsets.logger import configure_logging, get_logger
+```
+
+## ::: fastapi_toolsets.logger.configure_logging
+
+## ::: fastapi_toolsets.logger.get_logger

docs/reference/metrics.md

@@ -0,0 +1,15 @@
+# `metrics`
+
+Here's the reference for the Prometheus metrics registry and endpoint handler.
+
+You can import them directly from `fastapi_toolsets.metrics`:
+
+```python
+from fastapi_toolsets.metrics import Metric, MetricsRegistry, init_metrics
+```
+
+## ::: fastapi_toolsets.metrics.registry.Metric
+
+## ::: fastapi_toolsets.metrics.registry.MetricsRegistry
+
+## ::: fastapi_toolsets.metrics.handler.init_metrics

docs/reference/models.md

@@ -0,0 +1,34 @@
+# `models`
+
+Here's the reference for the SQLAlchemy model mixins provided by the `models` module.
+
+You can import them directly from `fastapi_toolsets.models`:
+
+```python
+from fastapi_toolsets.models import (
+    EventSession,
+    ModelEvent,
+    UUIDMixin,
+    UUIDv7Mixin,
+    CreatedAtMixin,
+    UpdatedAtMixin,
+    TimestampMixin,
+    listens_for,
+)
+```
+
+## ::: fastapi_toolsets.models.EventSession
+
+## ::: fastapi_toolsets.models.ModelEvent
+
+## ::: fastapi_toolsets.models.UUIDMixin
+
+## ::: fastapi_toolsets.models.UUIDv7Mixin
+
+## ::: fastapi_toolsets.models.CreatedAtMixin
+
+## ::: fastapi_toolsets.models.UpdatedAtMixin
+
+## ::: fastapi_toolsets.models.TimestampMixin
+
+## ::: fastapi_toolsets.models.listens_for

docs/reference/pytest.md

@@ -0,0 +1,26 @@
+# `pytest`
+
+Here's the reference for all testing utilities and pytest fixtures.
+
+You can import them directly from `fastapi_toolsets.pytest`:
+
+```python
+from fastapi_toolsets.pytest import (
+    register_fixtures,
+    create_async_client,
+    create_db_session,
+    worker_database_url,
+    create_worker_database,
+    cleanup_tables,
+)
+```
+
+## ::: fastapi_toolsets.pytest.plugin.register_fixtures
+
+## ::: fastapi_toolsets.pytest.utils.create_async_client
+
+## ::: fastapi_toolsets.pytest.utils.create_db_session
+
+## ::: fastapi_toolsets.pytest.utils.worker_database_url
+
+## ::: fastapi_toolsets.pytest.utils.create_worker_database

docs/reference/schemas.md

@@ -0,0 +1,46 @@
+# `schemas`
+
+Here's the reference for all response models and types provided by the `schemas` module.
+
+You can import them directly from `fastapi_toolsets.schemas`:
+
+```python
+from fastapi_toolsets.schemas import (
+    PydanticBase,
+    ResponseStatus,
+    ApiError,
+    BaseResponse,
+    Response,
+    ErrorResponse,
+    OffsetPagination,
+    CursorPagination,
+    PaginationType,
+    PaginatedResponse,
+    OffsetPaginatedResponse,
+    CursorPaginatedResponse,
+)
+```
+
+## ::: fastapi_toolsets.schemas.PydanticBase
+
+## ::: fastapi_toolsets.schemas.ResponseStatus
+
+## ::: fastapi_toolsets.schemas.ApiError
+
+## ::: fastapi_toolsets.schemas.BaseResponse
+
+## ::: fastapi_toolsets.schemas.Response
+
+## ::: fastapi_toolsets.schemas.ErrorResponse
+
+## ::: fastapi_toolsets.schemas.OffsetPagination
+
+## ::: fastapi_toolsets.schemas.CursorPagination
+
+## ::: fastapi_toolsets.schemas.PaginationType
+
+## ::: fastapi_toolsets.schemas.PaginatedResponse
+
+## ::: fastapi_toolsets.schemas.OffsetPaginatedResponse
+
+## ::: fastapi_toolsets.schemas.CursorPaginatedResponse

docs_src/examples/pagination_search/app.py

@@ -0,0 +1,11 @@
+from fastapi import FastAPI
+
+from fastapi_toolsets.exceptions import init_exceptions_handlers
+
+from .db import db
+from .routes import router
+
+app = FastAPI()
+db.install(app=app)
+init_exceptions_handlers(app=app)
+app.include_router(router=router)

docs_src/examples/pagination_search/crud.py

@@ -0,0 +1,21 @@
+from fastapi_toolsets.crud import CrudFactory
+
+from .models import Article, Category
+
+ArticleCrud = CrudFactory(
+    model=Article,
+    cursor_column=Article.created_at,
+    searchable_fields=[  # default fields for full-text search
+        Article.title,
+        Article.body,
+        (Article.category, Category.name),
+    ],
+    facet_fields=[  # fields exposed as filter dropdowns
+        Article.status,
+        (Article.category, Category.name),
+    ],
+    order_fields=[  # fields exposed for client-driven ordering
+        Article.title,
+        Article.created_at,
+    ],
+)

docs_src/examples/pagination_search/db.py

@@ -0,0 +1,14 @@
+from typing import Annotated
+
+from fastapi import Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from fastapi_toolsets.db import Database
+
+DATABASE_URL = "postgresql+asyncpg://postgres:postgres@localhost:5432/postgres"
+
+db = Database(url=DATABASE_URL)
+
+get_db = db
+
+SessionDep = Annotated[AsyncSession, Depends(db)]

docs_src/examples/pagination_search/models.py

@@ -0,0 +1,34 @@
+import uuid
+
+from sqlalchemy import Boolean, ForeignKey, String, Text
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship
+
+from fastapi_toolsets.models import CreatedAtMixin
+
+
+class Base(DeclarativeBase):
+    pass
+
+
+class Category(Base):
+    __tablename__ = "categories"
+
+    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(64), unique=True)
+
+    articles: Mapped[list["Article"]] = relationship(back_populates="category")
+
+
+class Article(Base, CreatedAtMixin):
+    __tablename__ = "articles"
+
+    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
+    title: Mapped[str] = mapped_column(String(256))
+    body: Mapped[str] = mapped_column(Text)
+    status: Mapped[str] = mapped_column(String(32))
+    published: Mapped[bool] = mapped_column(Boolean, default=False)
+    category_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("categories.id"), nullable=True
+    )
+
+    category: Mapped["Category | None"] = relationship(back_populates="articles")

docs_src/examples/pagination_search/routes.py

@@ -0,0 +1,79 @@
+from typing import Annotated
+
+from fastapi import APIRouter, Depends
+
+from fastapi_toolsets.schemas import (
+    CursorPaginatedResponse,
+    OffsetPaginatedResponse,
+    PaginatedResponse,
+)
+
+from .crud import ArticleCrud
+from .db import SessionDep
+from .models import Article
+from .schemas import ArticleRead
+
+router = APIRouter(prefix="/articles")
+
+
+@router.get("/offset")
+async def list_articles_offset(
+    session: SessionDep,
+    params: Annotated[
+        dict,
+        Depends(
+            ArticleCrud.offset_paginate_params(
+                default_page_size=20,
+                max_page_size=100,
+                default_order_field=Article.created_at,
+            )
+        ),
+    ],
+) -> OffsetPaginatedResponse[ArticleRead]:
+    return await ArticleCrud.offset_paginate(
+        session=session,
+        **params,
+        schema=ArticleRead,
+    )
+
+
+@router.get("/cursor")
+async def list_articles_cursor(
+    session: SessionDep,
+    params: Annotated[
+        dict,
+        Depends(
+            ArticleCrud.cursor_paginate_params(
+                default_page_size=20,
+                max_page_size=100,
+                default_order_field=Article.created_at,
+            )
+        ),
+    ],
+) -> CursorPaginatedResponse[ArticleRead]:
+    return await ArticleCrud.cursor_paginate(
+        session=session,
+        **params,
+        schema=ArticleRead,
+    )
+
+
+@router.get("/")
+async def list_articles(
+    session: SessionDep,
+    params: Annotated[
+        dict,
+        Depends(
+            ArticleCrud.paginate_params(
+                default_page_size=20,
+                max_page_size=100,
+                default_order_field=Article.created_at,
+            )
+        ),
+    ],
+) -> PaginatedResponse[ArticleRead]:
+    return await ArticleCrud.paginate(
+        session,
+        **params,
+        schema=ArticleRead,
+    )

docs_src/examples/pagination_search/schemas.py

@@ -0,0 +1,13 @@
+import datetime
+import uuid
+
+from fastapi_toolsets.schemas import PydanticBase
+
+
+class ArticleRead(PydanticBase):
+    id: uuid.UUID
+    created_at: datetime.datetime
+    title: str
+    status: str
+    published: bool
+    category_id: uuid.UUID | None

index.html

@@ -1,18 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-  <meta charset="utf-8">
-  <title>Redirecting</title>
-  <noscript>
-    <meta http-equiv="refresh" content="1; url=stable/" />
-  </noscript>
-  <script>
-    window.location.replace(
-      "stable/" + window.location.search + window.location.hash
-    );
-  </script>
-</head>
-<body>
-  Redirecting to <a href="stable/">stable/</a>...
-</body>
-</html>

pyproject.toml

@@ -0,0 +1,127 @@
+[project]
+name = "fastapi-toolsets"
+version = "5.1.0"
+description = "Production-ready utilities for FastAPI applications"
+readme = "README.md"
+license = "MIT"
+license-files = ["LICENSE"]
+requires-python = ">=3.11"
+authors = [
+    { name = "d3vyce", email = "contact@d3vyce.fr" }
+]
+keywords = ["fastapi", "sqlalchemy", "postgresql"]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Framework :: AsyncIO",
+    "Framework :: FastAPI",
+    "Framework :: Pydantic",
+    "Intended Audience :: Developers",
+    "Intended Audience :: Information Technology",
+    "Intended Audience :: System Administrators",
+    "License :: OSI Approved :: MIT License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+    "Topic :: Software Development :: Libraries",
+    "Topic :: Software Development",
+    "Typing :: Typed",
+]
+dependencies = [
+    "asyncpg>=0.29.0",
+    "fastapi>=0.100.0",
+    "pydantic>=2.0",
+    "sqlalchemy[asyncio]>=2.0",
+]
+
+[project.urls]
+Homepage = "https://github.com/d3vyce/fastapi-toolsets"
+Documentation = "https://fastapi-toolsets.d3vyce.fr/"
+Repository = "https://github.com/d3vyce/fastapi-toolsets"
+Issues = "https://github.com/d3vyce/fastapi-toolsets/issues"
+
+[project.optional-dependencies]
+cli = [
+    "typer>=0.9.0",
+]
+metrics = [
+    "prometheus_client>=0.20.0",
+]
+pytest = [
+    "httpx>=0.25.0",
+    "pytest-xdist>=3.0.0",
+    "pytest>=8.0.0",
+]
+all = [
+    "fastapi-toolsets[cli,metrics,pytest]",
+]
+
+[project.scripts]
+manager = "fastapi_toolsets.cli.app:cli"
+
+[dependency-groups]
+dev = [
+    {include-group = "tests"},
+    {include-group = "docs"},
+    {include-group = "docs-src"},
+    "fastapi-toolsets[all]",
+    "prek>=0.3.8",
+    "ruff>=0.1.0",
+    "ty>=0.0.1a0",
+]
+tests = [
+    "async-lru>=1.0",
+    "coverage>=7.0.0",
+    "httpx>=0.25.0",
+    "pytest-anyio>=0.0.0",
+    "pytest-cov>=4.0.0",
+    "pytest-xdist>=3.0.0",
+    "pytest>=8.0.0",
+]
+docs = [
+    "mike",
+    "mkdocstrings-python>=2.0.2",
+    "zensical>=0.0.30",
+]
+docs-src = [
+    "bcrypt>=4.0.0",
+]
+
+[build-system]
+requires = ["uv_build>=0.10,<0.12.0"]
+build-backend = "uv_build"
+
+[tool.ruff.format]
+exclude = ["*.md"]
+
+[tool.ruff.lint]
+extend-select = ["E712"]
+
+[tool.ruff.lint.flake8-bugbear]
+extend-immutable-calls = ["fastapi.Depends"]
+
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = ["RUF012", "RUF059", "SIM117", "DTZ001", "S110", "BLE001"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+filterwarnings = [
+    "ignore::DeprecationWarning",
+]
+
+[tool.coverage.run]
+source = ["src/fastapi_toolsets"]
+branch = true
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "if TYPE_CHECKING:",
+    "raise NotImplementedError",
+]
+
+[tool.uv.sources]
+mike = { git = "https://github.com/squidfunk/mike.git", tag = "2.2.0+zensical-0.1.0" }

src/fastapi_toolsets/__init__.py

@@ -0,0 +1,27 @@
+"""FastAPI utilities package.
+
+Provides CRUD operations, fixtures, CLI, and standardized API responses
+for FastAPI with async SQLAlchemy and PostgreSQL.
+
+Example usage:
+    from fastapi import FastAPI, Depends
+    from fastapi_toolsets.exceptions import init_exceptions_handlers
+    from fastapi_toolsets.crud import CrudFactory
+    from fastapi_toolsets.db import Database
+    from fastapi_toolsets.schemas import Response
+
+    db = Database("postgresql+asyncpg://postgres:postgres@localhost/app")
+
+    app = FastAPI()
+    db.install(app)
+    init_exceptions_handlers(app)
+
+    UserCrud = CrudFactory(User)
+
+    @app.get("/users/{user_id}", response_model=Response[dict])
+    async def get_user(user_id: int, session = Depends(db)):
+        user = await UserCrud.get(session, [User.id == user_id])
+        return Response(data={"user": user.username}, message="Success")
+"""
+
+__version__ = "5.1.0"

src/fastapi_toolsets/_imports.py

@@ -0,0 +1,9 @@
+"""Optional dependency helpers."""
+
+
+def require_extra(package: str, extra: str) -> None:
+    """Raise *ImportError* with an actionable install instruction."""
+    raise ImportError(
+        f"'{package}' is required to use this module. "
+        f"Install it with: pip install fastapi-toolsets[{extra}]"
+    )

src/fastapi_toolsets/cli/__init__.py

@@ -0,0 +1,5 @@
+"""CLI for FastAPI projects."""
+
+from .utils import async_command
+
+__all__ = ["async_command"]

src/fastapi_toolsets/cli/app.py

@@ -0,0 +1,37 @@
+"""Main CLI application."""
+
+try:
+    import typer
+except ImportError:
+    from .._imports import require_extra
+
+    require_extra(package="typer", extra="cli")
+
+from ..logger import configure_logging
+from .config import get_custom_cli
+from .pyproject import load_pyproject
+
+# Use custom CLI if configured, otherwise create default one
+_custom_cli = get_custom_cli()
+
+if _custom_cli is not None:
+    cli = _custom_cli
+else:
+    cli = typer.Typer(
+        name="manager",
+        help="CLI utilities for FastAPI projects.",
+        no_args_is_help=True,
+    )
+
+_config = load_pyproject()
+if _config.get("fixtures") and _config.get("db_context"):
+    from .commands.fixtures import fixture_cli
+
+    cli.add_typer(fixture_cli, name="fixtures")
+
+
+@cli.callback()
+def main(ctx: typer.Context) -> None:
+    """FastAPI utilities CLI."""
+    configure_logging()
+    ctx.ensure_object(dict)

src/fastapi_toolsets/cli/commands/__init__.py

@@ -0,0 +1 @@
+"""Built-in CLI commands."""

src/fastapi_toolsets/cli/commands/fixtures.py

@@ -0,0 +1,103 @@
+"""Fixture management commands."""
+
+from typing import Annotated
+
+import typer
+from rich.console import Console
+from rich.table import Table
+
+from ...fixtures import Context, LoadStrategy
+from ...logger import get_logger
+from ..config import get_db_context, get_fixtures_registry
+from ..utils import async_command
+
+fixture_cli = typer.Typer(
+    name="fixtures",
+    help="Manage database fixtures.",
+    no_args_is_help=True,
+)
+console = Console()
+logger = get_logger()
+
+
+@fixture_cli.command("list")
+def list_fixtures(
+    ctx: typer.Context,
+    context: Annotated[
+        str | None,
+        typer.Option(
+            "--context",
+            "-c",
+            help="Filter by context.",
+        ),
+    ] = None,
+) -> None:
+    """List all registered fixtures."""
+    registry = get_fixtures_registry()
+    fixtures = registry.get_by_context(context) if context else registry.get_all()
+
+    if not fixtures:
+        logger.info("No fixtures found.")
+        return
+
+    table = Table("Name", "Contexts", "Dependencies")
+
+    for fixture in fixtures:
+        contexts = ", ".join(fixture.contexts)
+        deps = ", ".join(fixture.depends_on) if fixture.depends_on else "-"
+        table.add_row(fixture.name, contexts, deps)
+
+    console.print(table)
+    logger.info("Total: %d fixture(s)", len(fixtures))
+
+
+@fixture_cli.command("load")
+@async_command
+async def load(
+    ctx: typer.Context,
+    contexts: Annotated[
+        list[str] | None,
+        typer.Argument(help="Contexts to load.", envvar="FIXTURES_CONTEXT"),
+    ] = None,
+    strategy: Annotated[
+        LoadStrategy,
+        typer.Option("--strategy", "-s", help="Load strategy."),
+    ] = LoadStrategy.MERGE,
+    dry_run: Annotated[
+        bool,
+        typer.Option(
+            "--dry-run", "-n", help="Show what would be loaded without loading."
+        ),
+    ] = False,
+) -> None:
+    """Load fixtures into the database."""
+    from ...fixtures import load_fixtures_by_context
+
+    registry = get_fixtures_registry()
+    db_context = get_db_context()
+
+    context_list = contexts or [Context.BASE.value]
+
+    ordered = registry.resolve_context_dependencies(*context_list)
+
+    if not ordered:
+        logger.info("No fixtures to load for the specified context(s).")
+        return
+
+    if dry_run:
+        logger.info("Fixtures to load (%s strategy):", strategy.value)
+        for name in ordered:
+            variants = registry.get_load_variants(name, *context_list)
+            instances = [inst for v in variants for inst in v.func()]
+            model_name = type(instances[0]).__name__ if instances else "?"
+            logger.info("  - %s: %d %s(s)", name, len(instances), model_name)
+        logger.info("[Dry run - no changes made]")
+        return
+
+    async with db_context() as session:
+        result = await load_fixtures_by_context(
+            session, registry, *context_list, strategy=strategy
+        )
+
+    total = sum(len(items) for items in result.values())
+    logger.info("Loaded %d record(s) successfully.", total)

src/fastapi_toolsets/cli/config.py

@@ -0,0 +1,136 @@
+"""CLI configuration and dynamic imports."""
+
+from __future__ import annotations
+
+import importlib
+import sys
+from typing import TYPE_CHECKING, Any, Literal, TypeVar, overload
+
+import typer
+
+from .pyproject import find_pyproject, load_pyproject
+
+if TYPE_CHECKING:
+    from ..fixtures import FixtureRegistry
+
+T = TypeVar("T")
+
+
+def _ensure_project_in_path():
+    """Add project root to sys.path if not installed in editable mode."""
+    pyproject = find_pyproject()
+    if pyproject:
+        project_root = str(pyproject.parent)
+        if project_root not in sys.path:
+            sys.path.insert(0, project_root)
+
+
+def import_from_string(import_path: str) -> Any:
+    """Import an object from a dotted string path.
+
+    Args:
+        import_path: Import path in ``"module.submodule:attribute"`` format
+
+    Returns:
+        The imported attribute
+
+    Raises:
+        typer.BadParameter: If the import path is invalid or import fails
+    """
+    if ":" not in import_path:
+        raise typer.BadParameter(
+            f"Invalid import path '{import_path}'. Expected format: 'module:attribute'"
+        )
+
+    module_path, attr_name = import_path.rsplit(":", 1)
+
+    _ensure_project_in_path()
+
+    try:
+        module = importlib.import_module(module_path)
+    except ImportError as e:
+        raise typer.BadParameter(f"Cannot import module '{module_path}': {e}")
+
+    if not hasattr(module, attr_name):
+        raise typer.BadParameter(
+            f"Module '{module_path}' has no attribute '{attr_name}'"
+        )
+
+    return getattr(module, attr_name)
+
+
+@overload
+def get_config_value(key: str, required: Literal[True]) -> Any: ...  # pragma: no cover
+@overload
+def get_config_value(
+    key: str, required: bool = False
+) -> Any | None: ...  # pragma: no cover
+def get_config_value(key: str, required: bool = False) -> Any | None:
+    """Get a configuration value from pyproject.toml.
+
+    Args:
+        key: The configuration key in [tool.fastapi-toolsets].
+        required: If True, raises an error when the key is missing.
+
+    Returns:
+        The configuration value, or None if not found and not required.
+
+    Raises:
+        typer.BadParameter: If required=True and the key is missing.
+    """
+    config = load_pyproject()
+    value = config.get(key)
+
+    if required and value is None:
+        raise typer.BadParameter(
+            f"No '{key}' configured. "
+            f"Add '{key}' to [tool.fastapi-toolsets] in pyproject.toml."
+        )
+
+    return value
+
+
+@overload
+def _import_typed(
+    key: str, expected_type: type[T], *, required: Literal[True]
+) -> T: ...  # pragma: no cover
+@overload
+def _import_typed(
+    key: str, expected_type: type[T], *, required: bool
+) -> T | None: ...  # pragma: no cover
+def _import_typed(key: str, expected_type: type[T], *, required: bool) -> T | None:
+    """Import a config value by key and validate its type.
+
+    Raises:
+        typer.BadParameter: If required and missing, or if the imported
+            value isn't an instance of *expected_type*.
+    """
+    import_path = get_config_value(key, required=required)
+    if not import_path:
+        return None
+
+    obj = import_from_string(import_path)
+    if not isinstance(obj, expected_type):
+        raise typer.BadParameter(
+            f"'{key}' must be a {expected_type.__name__} instance, got {type(obj).__name__}"
+        )
+
+    return obj
+
+
+def get_fixtures_registry() -> FixtureRegistry:
+    """Import and return the fixtures registry from config."""
+    from ..fixtures import FixtureRegistry
+
+    return _import_typed("fixtures", FixtureRegistry, required=True)
+
+
+def get_db_context() -> Any:
+    """Import and return the db_context function from config."""
+    import_path = get_config_value("db_context", required=True)
+    return import_from_string(import_path)
+
+
+def get_custom_cli() -> typer.Typer | None:
+    """Import and return the custom CLI Typer instance from config."""
+    return _import_typed("custom_cli", typer.Typer, required=False)

src/fastapi_toolsets/cli/pyproject.py

@@ -0,0 +1,49 @@
+"""Pyproject.toml discovery and loading."""
+
+import tomllib
+from pathlib import Path
+
+TOOL_NAME = "fastapi-toolsets"
+
+
+def find_pyproject(start_path: Path | None = None) -> Path | None:
+    """Find pyproject.toml by walking up the directory tree.
+
+    Similar to how pytest, black, and ruff discover their config files.
+
+    Args:
+        start_path: Directory to start searching from. Defaults to cwd.
+
+    Returns:
+        Path to pyproject.toml, or None if not found.
+    """
+    path = (start_path or Path.cwd()).resolve()
+
+    for directory in [path, *path.parents]:
+        pyproject = directory / "pyproject.toml"
+        if pyproject.is_file():
+            return pyproject
+
+    return None
+
+
+def load_pyproject(path: Path | None = None) -> dict:
+    """Load tool configuration from pyproject.toml.
+
+    Args:
+        path: Explicit path to pyproject.toml. If None, searches up from cwd.
+
+    Returns:
+        The [tool.fastapi-toolsets] section as a dict, or empty dict if not found.
+    """
+    pyproject_path = path or find_pyproject()
+
+    if not pyproject_path:
+        return {}
+
+    try:
+        with open(pyproject_path, "rb") as f:
+            data = tomllib.load(f)
+        return data.get("tool", {}).get(TOOL_NAME, {})
+    except (OSError, tomllib.TOMLDecodeError):
+        return {}

src/fastapi_toolsets/cli/utils.py

@@ -0,0 +1,30 @@
+"""CLI utility functions."""
+
+import functools
+from collections.abc import Callable, Coroutine
+from typing import Any, ParamSpec, TypeVar
+
+P = ParamSpec("P")
+T = TypeVar("T")
+
+
+def async_command(func: Callable[P, Coroutine[Any, Any, T]]) -> Callable[P, T]:
+    """Decorator to run an async function as a sync CLI command.
+
+    Example:
+        ```python
+        @fixture_cli.command("load")
+        @async_command
+        async def load(ctx: typer.Context) -> None:
+            async with get_db_context() as session:
+                await load_fixtures(session, registry)
+        ```
+    """
+
+    @functools.wraps(func)
+    def wrapper(*args: P.args, **kwargs: P.kwargs) -> T:
+        import asyncio
+
+        return asyncio.run(func(*args, **kwargs))
+
+    return wrapper

src/fastapi_toolsets/crud/__init__.py

@@ -0,0 +1,37 @@
+"""Generic async CRUD operations for SQLAlchemy models."""
+
+from ..exceptions import (
+    InvalidFacetFilterError,
+    InvalidSearchColumnError,
+    NoSearchableFieldsError,
+    UnsupportedFacetTypeError,
+)
+from ..schemas import PaginationType
+from ..types import (
+    FacetFieldType,
+    JoinType,
+    M2MFieldType,
+    OrderByClause,
+    OrderFieldType,
+    SearchFieldType,
+)
+from .factory import AsyncCrud, CrudFactory
+from .search import SearchConfig, get_searchable_fields
+
+__all__ = [
+    "AsyncCrud",
+    "CrudFactory",
+    "FacetFieldType",
+    "InvalidFacetFilterError",
+    "InvalidSearchColumnError",
+    "JoinType",
+    "M2MFieldType",
+    "NoSearchableFieldsError",
+    "OrderByClause",
+    "OrderFieldType",
+    "PaginationType",
+    "SearchConfig",
+    "SearchFieldType",
+    "UnsupportedFacetTypeError",
+    "get_searchable_fields",
+]

src/fastapi_toolsets/crud/search.py

@@ -0,0 +1,411 @@
+"""Search utilities for AsyncCrud."""
+
+import functools
+from collections.abc import Sequence
+from dataclasses import dataclass, replace
+from typing import TYPE_CHECKING, Any, Literal
+
+from sqlalchemy import String, and_, distinct, func, or_, select
+from sqlalchemy.dialects.postgresql import aggregate_order_by
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase
+from sqlalchemy.orm.attributes import InstrumentedAttribute
+from sqlalchemy.types import (
+    ARRAY,
+    Boolean,
+    Date,
+    DateTime,
+    Enum,
+    Integer,
+    Numeric,
+    Time,
+    Uuid,
+)
+
+from ..exceptions import (
+    InvalidFacetFilterError,
+    InvalidSearchColumnError,
+    NoSearchableFieldsError,
+    UnsupportedFacetTypeError,
+)
+from ..types import FacetFieldType, SearchFieldType
+
+if TYPE_CHECKING:
+    from sqlalchemy.sql.elements import ColumnElement
+
+
+@dataclass
+class SearchConfig:
+    """Advanced search configuration.
+
+    Attributes:
+        query: The search string
+        fields: Fields to search (columns or tuples for relationships)
+        case_sensitive: Case-sensitive search (default: False)
+        match_mode: "any" (OR) or "all" (AND) to combine fields
+    """
+
+    query: str
+    fields: Sequence[SearchFieldType] | None = None
+    case_sensitive: bool = False
+    match_mode: Literal["any", "all"] = "any"
+
+
+@functools.lru_cache(maxsize=128)
+def get_searchable_fields(
+    model: type[DeclarativeBase],
+    *,
+    include_relationships: bool = True,
+    max_depth: int = 1,
+) -> list[SearchFieldType]:
+    """Auto-detect String fields on a model and its relationships.
+
+    Args:
+        model: SQLAlchemy model class
+        include_relationships: Include fields from many-to-one/one-to-one relationships
+        max_depth: Max depth for relationship traversal (default: 1)
+
+    Returns:
+        List of columns and tuples (relationship, column)
+    """
+    fields: list[SearchFieldType] = []
+    mapper = model.__mapper__
+
+    # Direct String columns
+    for col in mapper.columns:
+        if isinstance(col.type, String):
+            fields.append(getattr(model, col.key))
+
+    # Relationships (one-to-one, many-to-one only)
+    if include_relationships and max_depth > 0:
+        for rel_name, rel_prop in mapper.relationships.items():
+            if rel_prop.uselist:  # Skip collections (one-to-many, many-to-many)
+                continue
+
+            rel_attr = getattr(model, rel_name)
+            related_model = rel_prop.mapper.class_
+
+            for col in related_model.__mapper__.columns:
+                if isinstance(col.type, String):
+                    fields.append((rel_attr, getattr(related_model, col.key)))
+
+    return fields
+
+
+def build_search_filters(
+    model: type[DeclarativeBase],
+    search: str | SearchConfig,
+    search_fields: Sequence[SearchFieldType] | None = None,
+    default_fields: Sequence[SearchFieldType] | None = None,
+    search_column: str | None = None,
+) -> tuple[list["ColumnElement[bool]"], list[InstrumentedAttribute[Any]]]:
+    """Build SQLAlchemy filter conditions for search.
+
+    Args:
+        model: SQLAlchemy model class
+        search: Search string or SearchConfig
+        search_fields: Fields specified per-call (takes priority)
+        default_fields: Default fields (from ClassVar)
+        search_column: Optional key to narrow search to a single field.
+            Must match one of the resolved search field keys.
+
+    Returns:
+        Tuple of (filter_conditions, joins_needed)
+
+    Raises:
+        NoSearchableFieldsError: If no searchable field has been configured
+    """
+    # Normalize input
+    if isinstance(search, str):
+        config = SearchConfig(query=search, fields=search_fields)
+    else:
+        config = (
+            replace(search, fields=search_fields)
+            if search_fields is not None
+            else search
+        )
+
+    if not config.query or not config.query.strip():
+        return [], []
+
+    # Determine which fields to search
+    fields = config.fields or default_fields or get_searchable_fields(model)
+
+    if not fields:
+        raise NoSearchableFieldsError(model)
+
+    # Narrow to a single column when search_column is specified
+    if search_column is not None:
+        keys = search_field_keys(fields)
+        index = {k: f for k, f in zip(keys, fields)}
+        if search_column not in index:
+            raise InvalidSearchColumnError(search_column, sorted(index))
+        fields = [index[search_column]]
+
+    query = config.query.strip()
+    filters: list[ColumnElement[bool]] = []
+    joins: list[InstrumentedAttribute[Any]] = []
+    added_joins: set[str] = set()
+
+    for field in fields:
+        if isinstance(field, tuple):
+            # Relationship: (User.role, Role.name) or deeper
+            for rel in field[:-1]:
+                rel_key = str(rel)
+                if rel_key not in added_joins:
+                    joins.append(rel)
+                    added_joins.add(rel_key)
+            column = field[-1]
+        else:
+            column = field
+
+        # Build the filter (cast to String only when needed, to preserve
+        # pg_trgm GIN index usability on already-String columns)
+        column_as_string = (
+            column if isinstance(column.type, String) else column.cast(String)
+        )
+        if config.case_sensitive:
+            filters.append(column_as_string.like(f"%{query}%"))
+        else:
+            filters.append(column_as_string.ilike(f"%{query}%"))
+
+    if not filters:  # pragma: no cover
+        return [], []
+
+    # Combine based on match_mode
+    if config.match_mode == "any":
+        return [or_(*filters)], joins
+    else:
+        return filters, joins
+
+
+def search_field_keys(fields: Sequence[SearchFieldType]) -> list[str]:
+    """Return a human-readable key for each search field."""
+    return facet_keys(fields)
+
+
+def apply_search_joins(q: Any, joins: Sequence[Any]) -> Any:
+    """Apply relationship-based outer joins (from search/filter_by/facets) to a query.
+
+    Deduplicates by relationship identity so a join used by several fields
+    (e.g. search + a facet on the same relation) is only applied once.
+    """
+    seen: set[str] = set()
+    for rel in joins:
+        rel_key = str(rel)
+        if rel_key not in seen:
+            seen.add(rel_key)
+            q = q.outerjoin(rel)
+    return q
+
+
+def facet_keys(facet_fields: Sequence[FacetFieldType]) -> list[str]:
+    """Return a key for each facet field.
+
+    Args:
+        facet_fields: Sequence of facet fields — either direct columns or
+            relationship tuples ``(rel, ..., column)``.
+
+    Returns:
+        A list of string keys, one per facet field, in the same order.
+    """
+    keys: list[str] = []
+    for field in facet_fields:
+        if isinstance(field, tuple):
+            keys.append("__".join(el.key for el in field))
+        else:
+            keys.append(field.key)
+    return keys
+
+
+async def build_facets(
+    session: "AsyncSession",
+    model: type[DeclarativeBase],
+    facet_fields: Sequence[FacetFieldType],
+    *,
+    base_filters: "list[ColumnElement[bool]] | None" = None,
+    base_joins: list[InstrumentedAttribute[Any]] | None = None,
+    own_filters: "dict[str, ColumnElement[bool]] | None" = None,
+) -> dict[str, list[Any]]:
+    """Return distinct values for each facet field, respecting current filters.
+
+    Args:
+        session: DB async session
+        model: SQLAlchemy model class
+        facet_fields: Columns or relationship tuples to facet on
+        base_filters: Filter conditions already applied to the main query (search + caller filters)
+        base_joins: Relationship joins already applied to the main query
+        own_filters: Map of facet key -> the ``filter_by`` condition for that
+            same key (if any). Excluded from that facet's own subquery so
+            filtering on a facet doesn't collapse its own value list down to
+            just the filtered value.
+
+    Returns:
+        Dict mapping column key to sorted list of distinct non-None values
+    """
+    if not facet_fields:
+        return {}
+
+    keys = facet_keys(facet_fields)
+    own_filters = own_filters or {}
+
+    scalars: list[Any] = []
+    enum_classes: dict[str, Any] = {}
+
+    for field, key in zip(facet_fields, keys):
+        if isinstance(field, tuple):
+            # Relationship chain: (User.role, Role.name) — last element is the column
+            rels = field[:-1]
+            column = field[-1]
+        else:
+            rels = ()
+            column = field
+
+        col_type = column.property.columns[0].type
+        is_array = isinstance(col_type, ARRAY)
+        enum_classes[key] = getattr(col_type, "enum_class", None)
+
+        filters = [
+            *(base_filters or []),
+            *(f for k, f in own_filters.items() if k != key),
+        ]
+        joins = [*(base_joins or []), *rels]
+
+        if is_array:
+            unnested = apply_search_joins(
+                select(func.unnest(column).label("v")).select_from(model), joins
+            )
+            if filters:
+                unnested = unnested.where(and_(*filters))
+            unnested_sq = unnested.subquery()
+            v = unnested_sq.c.v
+            agg = (
+                select(func.array_agg(aggregate_order_by(distinct(v), v)))
+                .select_from(unnested_sq)
+                .where(v.isnot(None))
+            )
+        else:
+            agg = apply_search_joins(
+                select(
+                    func.array_agg(aggregate_order_by(distinct(column), column))
+                ).select_from(model),
+                joins,
+            )
+            agg = agg.where(and_(*filters, column.isnot(None)))
+
+        scalars.append(agg.scalar_subquery().label(key))
+
+    row = (await session.execute(select(*scalars))).one()
+
+    facets: dict[str, list[Any]] = {}
+    for key, values in zip(keys, row):
+        enum_class = enum_classes[key]
+        facets[key] = [
+            v.name if (enum_class is not None and isinstance(v, enum_class)) else v
+            for v in (values or [])
+        ]
+    return facets
+
+
+_EQUALITY_TYPES = (String, Integer, Numeric, Date, DateTime, Time, Enum, Uuid)
+"""Column types that support equality / IN filtering in build_filter_by."""
+
+
+def _coerce_bool(value: Any) -> bool:
+    """Coerce a string value to a Python bool for Boolean column filtering."""
+    if isinstance(value, bool):
+        return value
+    if isinstance(value, str):
+        if value.lower() == "true":
+            return True
+        if value.lower() == "false":
+            return False
+    raise ValueError(f"Cannot coerce {value!r} to bool")
+
+
+def build_filter_by(
+    filter_by: dict[str, Any],
+    facet_fields: Sequence[FacetFieldType],
+) -> tuple["dict[str, ColumnElement[bool]]", list[InstrumentedAttribute[Any]]]:
+    """Translate a {column_key: value} dict into SQLAlchemy filter conditions.
+
+    Args:
+        filter_by: Mapping of column key to scalar value or list of values
+        facet_fields: Declared facet fields to validate keys against
+
+    Returns:
+        Tuple of ({facet_key: filter_condition}, joins_needed). One filter
+        condition per key, so callers can identify (and exclude) a facet's
+        own filter when computing that facet's distinct values.
+
+    Raises:
+        InvalidFacetFilterError: If a key in filter_by is not a declared facet field
+    """
+    index: dict[
+        str, tuple[InstrumentedAttribute[Any], list[InstrumentedAttribute[Any]]]
+    ] = {}
+    for key, field in zip(facet_keys(facet_fields), facet_fields):
+        if isinstance(field, tuple):
+            rels = list(field[:-1])
+            column = field[-1]
+        else:
+            rels = []
+            column = field
+        index[key] = (column, rels)
+
+    valid_keys = set(index)
+    filters: dict[str, ColumnElement[bool]] = {}
+    joins: list[InstrumentedAttribute[Any]] = []
+    added_join_keys: set[str] = set()
+
+    for key, value in filter_by.items():
+        if key not in index:
+            raise InvalidFacetFilterError(key, valid_keys)
+
+        column, rels = index[key]
+
+        for rel in rels:
+            rel_key = str(rel)
+            if rel_key not in added_join_keys:
+                joins.append(rel)
+                added_join_keys.add(rel_key)
+
+        col_type = column.property.columns[0].type
+        if isinstance(col_type, Boolean):
+            coerce = _coerce_bool
+            if isinstance(value, list):
+                filters[key] = column.in_([coerce(v) for v in value])
+            else:
+                filters[key] = column == coerce(value)
+        elif isinstance(col_type, ARRAY):
+            if isinstance(value, list):
+                filters[key] = column.overlap(value)
+            else:
+                filters[key] = column.any(value)
+        elif isinstance(col_type, Enum):
+            enum_class = col_type.enum_class
+            if enum_class is not None:
+
+                def _coerce_enum(v: Any, enum_class: Any = enum_class) -> Any:
+                    if isinstance(v, enum_class):
+                        return v
+                    return enum_class[v]  # lookup by name: "PENDING", "RED"
+
+                if isinstance(value, list):
+                    filters[key] = column.in_([_coerce_enum(v) for v in value])
+                else:
+                    filters[key] = column == _coerce_enum(value)
+            else:  # pragma: no cover
+                if isinstance(value, list):
+                    filters[key] = column.in_(value)
+                else:
+                    filters[key] = column == value
+        elif isinstance(col_type, _EQUALITY_TYPES):
+            if isinstance(value, list):
+                filters[key] = column.in_(value)
+            else:
+                filters[key] = column == value
+        else:
+            raise UnsupportedFacetTypeError(key, type(col_type).__name__)
+
+    return filters, joins

src/fastapi_toolsets/db/__init__.py

@@ -0,0 +1,18 @@
+"""Database package: the ``Database`` facade plus PostgreSQL power-tools."""
+
+from .core import Database, transaction
+from .locks import LockMode, advisory_lock, lock_tables
+from .m2m import m2m_add, m2m_remove, m2m_set
+from .watch import wait_for_row_change
+
+__all__ = [
+    "Database",
+    "LockMode",
+    "advisory_lock",
+    "lock_tables",
+    "m2m_add",
+    "m2m_remove",
+    "m2m_set",
+    "transaction",
+    "wait_for_row_change",
+]

src/fastapi_toolsets/db/core.py

@@ -0,0 +1,322 @@
+"""The ``Database`` facade: session lifecycle, dependency, middleware, transactions."""
+
+from collections.abc import AsyncGenerator
+from contextlib import AbstractAsyncContextManager, asynccontextmanager
+from typing import Any
+
+from pydantic import PostgresDsn
+from sqlalchemy import exc as sa_exc
+from sqlalchemy.ext.asyncio import (
+    AsyncEngine,
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+from sqlalchemy.orm import DeclarativeBase
+from starlette.requests import Request
+from starlette.types import ASGIApp, Message, Receive, Scope, Send
+
+from ..exceptions import PoolExhaustedError
+from .locks import LockMode, lock_tables
+
+
+@asynccontextmanager
+async def transaction(
+    session: AsyncSession,
+) -> AsyncGenerator[AsyncSession, None]:
+    """Run a block inside a savepoint-aware transaction.
+
+    If *session* is already in a transaction, a nested transaction (savepoint)
+    is opened so the block can roll back independently. Otherwise a top-level
+    transaction is started. Commits on clean exit, rolls back on exception.
+
+    Args:
+        session: AsyncSession instance.
+
+    Yields:
+        The session within the transaction context.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import transaction
+
+        async with transaction(session):
+            session.add(model)
+        ```
+    """
+    if session.in_transaction():
+        async with session.begin_nested():
+            yield session
+    else:
+        async with session.begin():
+            yield session
+
+
+class _CommitOnResponseMiddleware:
+    """Commit the request's DB session before the response is sent."""
+
+    def __init__(self, app: ASGIApp, *, state_attr: str) -> None:
+        self.app = app
+        self.state_attr = state_attr
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if scope["type"] != "http":
+            await self.app(scope, receive, send)
+            return
+
+        async def send_wrapper(message: Message) -> None:
+            if message["type"] == "http.response.start":
+                # ``scope["state"]`` is the same dict ``request.state`` writes
+                # to, so this is the session stashed by the dependency.
+                state = scope.get("state")
+                session = state.get(self.state_attr) if state else None
+                if session is not None and session.in_transaction():
+                    await session.commit()
+            await send(message)
+
+        await self.app(scope, receive, send_wrapper)
+
+
+class Database:
+    """One object that owns the engine, sessions, dependency, and middleware.
+
+    Provide exactly one of *url* (the facade builds and disposes the engine) or
+    *engine* (an engine you own, e.g. for Alembic or ``event.listen``, left
+    untouched).
+
+    Args:
+        url: Database connection URL. Accepts a plain string or a Pydantic
+            :class:`~pydantic.PostgresDsn`.
+        engine: An existing :class:`AsyncEngine` to reuse instead of *url*.
+        session_class: Session class for the sessionmaker (e.g. ``EventSession``).
+        expire_on_commit: Expire attributes after commit. Defaults to ``False``.
+        autoflush: Autoflush the session before queries. Defaults to ``True``.
+        connect_args: DBAPI-level connection arguments forwarded to
+            :func:`create_async_engine` (URL mode only).
+        **engine_options: Extra keyword arguments forwarded to
+            :func:`create_async_engine` (URL mode only).
+
+    Raises:
+        TypeError: If neither or both of *url* and *engine* are given, or if
+            *connect_args*/*engine_options* are passed together with *engine*.
+
+    Example:
+        ```python
+        from fastapi import Depends, FastAPI
+        from fastapi_toolsets.db import Database
+
+        db = Database("postgresql+asyncpg://postgres:postgres@localhost/app")
+
+        app = FastAPI()
+        db.install(app)
+
+        @app.get("/users/{user_id}")
+        async def get_user(user_id: int, session=Depends(db)):
+            return await UserCrud.get(session, [User.id == user_id])
+        ```
+    """
+
+    def __init__(
+        self,
+        url: str | PostgresDsn | None = None,
+        *,
+        engine: AsyncEngine | None = None,
+        session_class: type[AsyncSession] = AsyncSession,
+        expire_on_commit: bool = False,
+        autoflush: bool = True,
+        connect_args: dict[str, Any] | None = None,
+        **engine_options: Any,
+    ) -> None:
+        if (url is None) == (engine is None):
+            raise TypeError(
+                "Database requires exactly one of 'url' or 'engine' "
+                "(got both or neither)."
+            )
+        if engine is not None and (engine_options or connect_args is not None):
+            raise TypeError(
+                "connect_args/engine_options are only valid in URL mode; "
+                "configure the engine you pass via 'engine=' yourself."
+            )
+
+        if engine is not None:
+            self._owns_engine = False
+            self.engine: AsyncEngine = engine
+        else:
+            assert url is not None  # guaranteed by the XOR check above
+            self._owns_engine = True
+            if connect_args is not None:
+                engine_options["connect_args"] = connect_args
+            # ``PostgresDsn`` (and other URL objects) are not str subclasses, so
+            # coerce to the string form SQLAlchemy expects.
+            self.engine = create_async_engine(str(url), **engine_options)
+        self._sessionmaker: async_sessionmaker[AsyncSession] = async_sessionmaker(
+            self.engine,
+            class_=session_class,
+            expire_on_commit=expire_on_commit,
+            autoflush=autoflush,
+        )
+        # Private, per-instance state attribute; cannot collide with another
+        # Database or be mismatched against the middleware.
+        self._state_attr = f"_ft_db_session_{id(self):x}"
+        self._middleware_installed = False
+        self._disposed = False
+
+    async def _dispose(self) -> None:
+        """Dispose the engine once, only if we own it (idempotent)."""
+        if self._owns_engine and not self._disposed:
+            self._disposed = True
+            await self.engine.dispose()
+
+    @asynccontextmanager
+    async def lifespan(self, app: Any) -> AsyncGenerator[None, None]:
+        """Dispose the engine on shutdown; use as ``FastAPI(lifespan=db.lifespan)``.
+
+        Args:
+            app: The ASGI application (unused; required by the lifespan protocol).
+
+        Yields:
+            Control to the application for its lifetime.
+
+        Example:
+            ```python
+            app = FastAPI(lifespan=db.lifespan)
+            ```
+        """
+        try:
+            yield
+        finally:
+            await self._dispose()
+
+    def install(self, app: Any) -> None:
+        """Wire the commit middleware and engine disposal onto *app*.
+
+        Args:
+            app: The FastAPI/Starlette application to wire.
+
+        Example:
+            ```python
+            @asynccontextmanager
+            async def lifespan(app):
+                ...  # your startup
+                yield
+                ...  # your shutdown
+
+            app = FastAPI(lifespan=lifespan)
+            db.install(app)
+            ```
+        """
+        app.add_middleware(_CommitOnResponseMiddleware, state_attr=self._state_attr)
+        self._middleware_installed = True
+
+        inner_lifespan = app.router.lifespan_context
+
+        @asynccontextmanager
+        async def _composed(app_: Any) -> AsyncGenerator[None, None]:
+            async with self.lifespan(app_), inner_lifespan(app_):
+                yield
+
+        app.router.lifespan_context = _composed
+
+    @asynccontextmanager
+    async def _open(self) -> AsyncGenerator[AsyncSession, None]:
+        """Open a session and eagerly acquire a connection (fail-fast on pool)."""
+        async with self._sessionmaker() as session:
+            try:
+                await session.connection()
+            except sa_exc.TimeoutError as e:
+                raise PoolExhaustedError() from e
+            yield session
+
+    async def __call__(self, request: Request) -> AsyncGenerator[AsyncSession, None]:
+        """FastAPI dependency: yield a session and commit once at the right time.
+
+        Args:
+            request: The incoming request (injected by FastAPI).
+
+        Yields:
+            An AsyncSession for the duration of the request.
+
+        Example:
+            ```python
+            @app.get("/users/{user_id}")
+            async def get_user(user_id: int, session=Depends(db)):
+                return await UserCrud.get(session, [User.id == user_id])
+            ```
+        """
+        async with self._open() as session:
+            setattr(request.state, self._state_attr, session)
+            yield session
+            if not self._middleware_installed and session.in_transaction():
+                await session.commit()
+
+    @asynccontextmanager
+    async def session(self) -> AsyncGenerator[AsyncSession, None]:
+        """Open a session outside request handlers (background tasks, CLI, tests).
+
+        Commits on clean exit, rolls back on exception.
+
+        Yields:
+            An AsyncSession ready for database operations.
+
+        Example:
+            ```python
+            async with db.session() as session:
+                user = await UserCrud.get(session, [User.id == 1])
+            ```
+        """
+        async with self._open() as session:
+            yield session
+            if session.in_transaction():
+                await session.commit()
+
+    @asynccontextmanager
+    async def begin(self) -> AsyncGenerator[AsyncSession, None]:
+        """Open a session already inside a transaction (sugar for the common case).
+
+        Equivalent to ``session()`` + :func:`transaction`. Commits on clean exit,
+        rolls back on exception.
+
+        Yields:
+            An AsyncSession open within a transaction.
+
+        Example:
+            ```python
+            async with db.begin() as session:
+                session.add(User(name="ada"))
+            ```
+        """
+        async with self.session() as session, transaction(session):
+            yield session
+
+    def lock_tables(
+        self,
+        tables: list[type[DeclarativeBase]],
+        *,
+        mode: LockMode = LockMode.SHARE_UPDATE_EXCLUSIVE,
+        timeout: str = "5s",
+    ) -> AbstractAsyncContextManager[AsyncSession]:
+        """Lock PostgreSQL tables for the duration of a dedicated transaction.
+
+        Opens its own session from the facade's sessionmaker, changes are
+        committed when the context exits.
+
+        Args:
+            tables: List of SQLAlchemy model classes to lock.
+            mode: Lock mode (default: ``SHARE UPDATE EXCLUSIVE``).
+            timeout: Lock timeout (default: ``"5s"``).
+
+        Yields:
+            The dedicated session, open within the locked transaction.
+
+        Raises:
+            LockTimeoutError: If the lock cannot be acquired within *timeout*.
+            PoolExhaustedError: If the connection pool is exhausted.
+
+        Example:
+            ```python
+            async with db.lock_tables([User, Account]) as session:
+                user = await UserCrud.get(session, [User.id == 1])
+                user.balance += 100
+            ```
+        """
+        return lock_tables(self._sessionmaker, tables, mode=mode, timeout=timeout)

src/fastapi_toolsets/db/locks.py

@@ -0,0 +1,185 @@
+"""PostgreSQL locking helpers: table locks and advisory locks."""
+
+from collections.abc import AsyncGenerator
+from contextlib import AbstractAsyncContextManager, asynccontextmanager
+from enum import Enum
+from typing import TypeVar
+
+import asyncpg
+from sqlalchemy import exc as sa_exc
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker
+from sqlalchemy.orm import DeclarativeBase
+
+from ..exceptions import LockTimeoutError, PoolExhaustedError
+
+_SessionT = TypeVar("_SessionT", bound=AsyncSession)
+
+
+def _is_lock_not_available(e: sa_exc.DBAPIError) -> bool:
+    return e.orig is not None and isinstance(
+        e.orig.__cause__, asyncpg.exceptions.LockNotAvailableError
+    )
+
+
+class LockMode(str, Enum):
+    """PostgreSQL table lock modes.
+
+    See: https://www.postgresql.org/docs/current/explicit-locking.html
+    """
+
+    ACCESS_SHARE = "ACCESS SHARE"
+    ROW_SHARE = "ROW SHARE"
+    ROW_EXCLUSIVE = "ROW EXCLUSIVE"
+    SHARE_UPDATE_EXCLUSIVE = "SHARE UPDATE EXCLUSIVE"
+    SHARE = "SHARE"
+    SHARE_ROW_EXCLUSIVE = "SHARE ROW EXCLUSIVE"
+    EXCLUSIVE = "EXCLUSIVE"
+    ACCESS_EXCLUSIVE = "ACCESS EXCLUSIVE"
+
+
+def lock_tables(
+    session_maker: async_sessionmaker[_SessionT],
+    tables: list[type[DeclarativeBase]],
+    *,
+    mode: LockMode = LockMode.SHARE_UPDATE_EXCLUSIVE,
+    timeout: str = "5s",
+) -> AbstractAsyncContextManager[_SessionT]:
+    """Lock PostgreSQL tables for the duration of a transaction.
+
+    Prefer the method on a :class:`Database` instance; use this
+    directly only when you manage your own session factory.
+
+    Args:
+        session_maker: Async session factory used to create the dedicated
+            session.
+        tables: List of SQLAlchemy model classes to lock.
+        mode: Lock mode (default: SHARE UPDATE EXCLUSIVE).
+        timeout: Lock timeout (default: "5s").
+
+    Yields:
+        The dedicated session, open within the locked transaction.
+
+    Raises:
+        LockTimeoutError: If the lock cannot be acquired within *timeout*.
+        PoolExhaustedError: If the connection pool is exhausted.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import lock_tables
+
+        async with lock_tables(session_maker, [User, Account]) as session:
+            user = await UserCrud.get(session, [User.id == 1])
+            user.balance += 100
+        ```
+    """
+    table_names = ",".join(table.__tablename__ for table in tables)
+
+    @asynccontextmanager
+    async def _lock() -> AsyncGenerator[_SessionT, None]:
+        async with session_maker() as session:
+            try:
+                await session.execute(text(f"SET LOCAL lock_timeout='{timeout}'"))
+                await session.execute(text(f"LOCK {table_names} IN {mode.value} MODE"))
+                yield session
+                await session.commit()
+            except sa_exc.TimeoutError as e:
+                await session.rollback()
+                raise PoolExhaustedError(
+                    f"Connection pool exhausted while locking '{table_names}'. "
+                ) from e
+            except sa_exc.DBAPIError as e:
+                await session.rollback()
+                if _is_lock_not_available(e):
+                    raise LockTimeoutError(
+                        f"Lock on '{table_names}' could not be acquired within {timeout}."
+                    ) from e
+                raise  # pragma: no cover
+            except BaseException:
+                await session.rollback()
+                raise
+
+    return _lock()
+
+
+@asynccontextmanager
+async def advisory_lock(
+    session: AsyncSession,
+    key: int | tuple[int, int],
+    *,
+    shared: bool = False,
+    nowait: bool = False,
+    timeout: str | None = None,
+) -> AsyncGenerator[bool, None]:
+    """Acquire a PostgreSQL session-level advisory lock.
+
+    Args:
+        session: AsyncSession instance.
+        key: Lock key, either a single ``int`` (bigint) or a ``(int, int)`` pair for namespacing.
+        shared: Acquire a shared lock (multiple holders allowed). Default is exclusive.
+        nowait: Return ``False`` immediately if the lock is unavailable instead of waiting.
+        timeout: Maximum wait time (e.g. ``"5s"``, ``"500ms"``). Raises ``DBAPIError``
+            if exceeded. Ignored when *nowait* is ``True``.
+
+    Yields:
+        ``True`` if the lock was acquired, ``False`` if *nowait* is ``True`` and the lock
+        is already held.
+
+    Raises:
+        LockTimeoutError: If *timeout* is set and the lock cannot be acquired in time.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import advisory_lock
+
+        async with advisory_lock(session, 42):
+            ...
+
+        async with advisory_lock(session, 42, nowait=True) as acquired:
+            if not acquired:
+                raise HTTPException(409, "Resource is locked")
+
+        async with advisory_lock(session, 42, timeout="5s"):
+            ...
+
+        async with advisory_lock(session, (1, user_id), shared=True):
+            ...
+        ```
+    """
+    suffix = "_shared" if shared else ""
+    acquire_fn = f"{'pg_try_advisory_lock' if nowait else 'pg_advisory_lock'}{suffix}"
+    release_fn = f"pg_advisory_unlock{suffix}"
+
+    if isinstance(key, tuple):
+        k1, k2 = key
+        args = "CAST(:k1 AS integer), CAST(:k2 AS integer)"
+        params: dict[str, int] = {"k1": k1, "k2": k2}
+    else:
+        args = ":k"
+        params = {"k": key}
+
+    acquire_sql = text(f"SELECT {acquire_fn}({args})")
+    release_sql = text(f"SELECT {release_fn}({args})")
+
+    # Lock management runs raw SQL on the caller's session. Guard it with
+    # ``no_autoflush`` so acquiring or releasing the lock never flushes the
+    # caller's pending ORM changes; SQLAlchemy 2.1 autoflushes on raw
+    # ``text()`` too, where 2.0 did not.
+    try:
+        with session.no_autoflush:
+            if timeout is not None and not nowait:
+                await session.execute(text(f"SET LOCAL lock_timeout='{timeout}'"))
+            result = await session.execute(acquire_sql, params)
+    except sa_exc.DBAPIError as e:
+        if _is_lock_not_available(e):
+            raise LockTimeoutError(
+                f"Advisory lock {key!r} could not be acquired within {timeout}."
+            ) from e
+        raise  # pragma: no cover
+    acquired = result.scalar() if nowait else True
+    try:
+        yield acquired
+    finally:
+        if acquired:
+            with session.no_autoflush:
+                await session.execute(release_sql, params)

src/fastapi_toolsets/db/m2m.py

@@ -0,0 +1,168 @@
+"""Many-to-Many association-table helpers (direct, without loading collections)."""
+
+from typing import Any, cast
+
+from sqlalchemy import ColumnElement, Table, delete, tuple_
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase, QueryableAttribute
+from sqlalchemy.orm.relationships import RelationshipProperty
+
+
+def _m2m_prop(rel_attr: QueryableAttribute) -> tuple[RelationshipProperty, Table]:  # type: ignore[type-arg]
+    """Return the validated M2M RelationshipProperty and its secondary table.
+
+    Raises TypeError if *rel_attr* is not a Many-to-Many relationship.
+    """
+    prop = rel_attr.property
+    if not isinstance(prop, RelationshipProperty) or prop.secondary is None:
+        raise TypeError(
+            f"m2m helpers require a Many-to-Many relationship attribute, "
+            f"got {rel_attr!r}. Use a relationship with a secondary table."
+        )
+    return prop, cast(Table, prop.secondary)
+
+
+def _parent_where(
+    prop: RelationshipProperty,  # type: ignore[type-arg]
+    instance: DeclarativeBase,
+) -> list[ColumnElement[bool]]:
+    """Build the WHERE clauses matching the owner side of *instance*."""
+    return [
+        assoc_col == getattr(instance, cast(str, parent_col.key))
+        for parent_col, assoc_col in prop.synchronize_pairs
+    ]
+
+
+async def m2m_add(
+    session: AsyncSession,
+    instance: DeclarativeBase,
+    rel_attr: QueryableAttribute,
+    *related: DeclarativeBase,
+    ignore_conflicts: bool = False,
+) -> None:
+    """Insert rows into a Many-to-Many association table without loading the ORM collection.
+
+    Args:
+        session: DB async session.
+        instance: The "owner" side model instance (e.g. the ``A`` in ``A.b_list``).
+        rel_attr: The M2M relationship attribute on the model class (e.g. ``A.b_list``).
+        *related: One or more related instances to associate with ``instance``.
+        ignore_conflicts: When ``True``, silently skip rows that already exist
+            in the association table (``ON CONFLICT DO NOTHING``).
+
+    Raises:
+        TypeError: If ``rel_attr`` is not a Many-to-Many relationship.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import m2m_add, transaction
+
+        async with transaction(session):
+            await m2m_add(session, post, Post.tags, tag1, tag2)
+        ```
+    """
+    prop, secondary = _m2m_prop(rel_attr)
+    if not related:
+        return
+
+    sync_pairs = prop.secondary_synchronize_pairs
+    assert sync_pairs is not None  # set whenever secondary is set
+
+    # synchronize_pairs:           [(parent_col, assoc_col), ...]
+    # secondary_synchronize_pairs: [(related_col, assoc_col), ...]
+    rows: list[dict[str, Any]] = []
+    for rel_instance in related:
+        row: dict[str, Any] = {}
+        for parent_col, assoc_col in prop.synchronize_pairs:
+            row[assoc_col.name] = getattr(instance, cast(str, parent_col.key))
+        for related_col, assoc_col in sync_pairs:
+            row[assoc_col.name] = getattr(rel_instance, cast(str, related_col.key))
+        rows.append(row)
+
+    stmt = pg_insert(secondary).values(rows)
+    if ignore_conflicts:
+        stmt = stmt.on_conflict_do_nothing()
+    await session.execute(stmt)
+
+
+async def m2m_remove(
+    session: AsyncSession,
+    instance: DeclarativeBase,
+    rel_attr: QueryableAttribute,
+    *related: DeclarativeBase,
+) -> None:
+    """Remove rows from a Many-to-Many association table without loading the ORM collection.
+
+    Args:
+        session: DB async session.
+        instance: The "owner" side model instance (e.g. the ``A`` in ``A.b_list``).
+        rel_attr: The M2M relationship attribute on the model class (e.g. ``A.b_list``).
+        *related: One or more related instances to disassociate from ``instance``.
+
+    Raises:
+        TypeError: If ``rel_attr`` is not a Many-to-Many relationship.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import m2m_remove, transaction
+
+        async with transaction(session):
+            await m2m_remove(session, post, Post.tags, tag1)
+        ```
+    """
+    prop, secondary = _m2m_prop(rel_attr)
+    if not related:
+        return
+
+    related_pairs = prop.secondary_synchronize_pairs
+    assert related_pairs is not None  # set whenever secondary is set
+
+    parent_where = _parent_where(prop, instance)
+
+    if len(related_pairs) == 1:
+        related_col, assoc_col = related_pairs[0]
+        related_values = [getattr(r, cast(str, related_col.key)) for r in related]
+        related_where = assoc_col.in_(related_values)
+    else:
+        assoc_cols = [ac for _, ac in related_pairs]
+        rel_cols = [rc for rc, _ in related_pairs]
+        related_values_t = [
+            tuple(getattr(r, cast(str, rc.key)) for rc in rel_cols) for r in related
+        ]
+        related_where = tuple_(*assoc_cols).in_(related_values_t)
+
+    await session.execute(delete(secondary).where(*parent_where, related_where))
+
+
+async def m2m_set(
+    session: AsyncSession,
+    instance: DeclarativeBase,
+    rel_attr: QueryableAttribute,
+    *related: DeclarativeBase,
+) -> None:
+    """Replace the entire Many-to-Many association set atomically.
+
+    Args:
+        session: DB async session.
+        instance: The "owner" side model instance (e.g. the ``A`` in ``A.b_list``).
+        rel_attr: The M2M relationship attribute on the model class (e.g. ``A.b_list``).
+        *related: The new complete set of related instances.
+
+    Raises:
+        TypeError: If ``rel_attr`` is not a Many-to-Many relationship.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import m2m_set, transaction
+
+        async with transaction(session):
+            await m2m_set(session, post, Post.tags, tag1, tag2)  # replaces all
+        ```
+    """
+    prop, secondary = _m2m_prop(rel_attr)
+
+    await session.execute(delete(secondary).where(*_parent_where(prop, instance)))
+
+    if related:
+        await m2m_add(session, instance, rel_attr, *related)

src/fastapi_toolsets/db/testing.py

@@ -0,0 +1,69 @@
+"""Database admin and test helpers: DDL and truncation."""
+
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.orm import DeclarativeBase
+
+
+async def create_database(
+    db_name: str,
+    *,
+    server_url: str,
+) -> None:
+    """Create a database.
+
+    Connects to *server_url* using ``AUTOCOMMIT`` isolation and issues a
+    ``CREATE DATABASE`` statement for *db_name*.
+
+    Args:
+        db_name: Name of the database to create.
+        server_url: URL used for server-level DDL (must point to an existing
+            database on the same server).
+
+    Example:
+        ```python
+        from fastapi_toolsets.db.testing import create_database
+
+        SERVER_URL = "postgresql+asyncpg://postgres:postgres@localhost/postgres"
+        await create_database("myapp_test", server_url=SERVER_URL)
+        ```
+    """
+    engine = create_async_engine(server_url, isolation_level="AUTOCOMMIT")
+    try:
+        async with engine.connect() as conn:
+            await conn.execute(text(f"CREATE DATABASE {db_name}"))
+    finally:
+        await engine.dispose()
+
+
+async def cleanup_tables(
+    session: AsyncSession,
+    base: type[DeclarativeBase],
+) -> None:
+    """Truncate all tables for fast between-test cleanup.
+
+    Executes a single ``TRUNCATE … RESTART IDENTITY CASCADE`` statement
+    across every table in *base*'s metadata.
+
+    This is a no-op when the metadata contains no tables.
+
+    Args:
+        session: An active async database session.
+        base: SQLAlchemy DeclarativeBase class containing model metadata.
+
+    Example:
+        ```python
+        @pytest.fixture
+        async def db_session(worker_db_url):
+            async with create_db_session(worker_db_url, Base) as session:
+                yield session
+                await cleanup_tables(session, Base)
+        ```
+    """
+    tables = base.metadata.sorted_tables
+    if not tables:
+        return
+
+    table_names = ", ".join(f'"{t.name}"' for t in tables)
+    await session.execute(text(f"TRUNCATE {table_names} RESTART IDENTITY CASCADE"))
+    await session.commit()

src/fastapi_toolsets/db/watch.py

@@ -0,0 +1,106 @@
+"""Row-watching helpers: poll a database row until it changes."""
+
+import asyncio
+from typing import Any, TypeVar
+
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase
+
+from ..exceptions import NotFoundError
+
+_M = TypeVar("_M", bound=DeclarativeBase)
+
+
+async def wait_for_row_change(
+    session: AsyncSession,
+    model: type[_M],
+    pk_value: Any,
+    *,
+    columns: list[str] | None = None,
+    interval: float = 0.5,
+    timeout: float | None = None,
+) -> _M:
+    """Poll a database row until a change is detected.
+
+    Queries the row every ``interval`` seconds and returns the model instance
+    once a change is detected in any column (or only the specified ``columns``).
+
+    Args:
+        session: AsyncSession instance.
+        model: SQLAlchemy model class.
+        pk_value: Primary key value of the row to watch.
+        columns: Optional list of column names to watch. If None, all columns
+            are watched.
+        interval: Polling interval in seconds (default: 0.5).
+        timeout: Maximum time to wait in seconds. None means wait forever.
+
+    Returns:
+        The refreshed model instance with updated values.
+
+    Raises:
+        NotFoundError: If the row does not exist or is deleted during polling.
+        TimeoutError: If timeout expires before a change is detected.
+
+    Example:
+        ```python
+        from fastapi_toolsets.db import wait_for_row_change
+
+        # Wait for any column to change
+        updated = await wait_for_row_change(session, User, user_id)
+
+        # Watch specific columns with a timeout
+        updated = await wait_for_row_change(
+            session, User, user_id,
+            columns=["status", "email"],
+            interval=1.0,
+            timeout=30.0,
+        )
+        ```
+    """
+    bind = getattr(session, "bind", None)
+    if bind is None:
+        raise TypeError(
+            "wait_for_row_change requires a session bound to an engine "
+            "(session.bind is None)"
+        )
+    watcher = AsyncSession(bind=bind)
+    try:
+
+        async def _reload() -> _M | None:
+            await watcher.rollback()
+            return await watcher.get(model, pk_value, populate_existing=True)
+
+        instance = await _reload()
+        if instance is None:
+            raise NotFoundError(f"{model.__name__} with pk={pk_value!r} not found")
+
+        if columns is not None:
+            watch_cols = columns
+        else:
+            watch_cols = [attr.key for attr in model.__mapper__.column_attrs]
+
+        initial = {col: getattr(instance, col) for col in watch_cols}
+
+        elapsed = 0.0
+        while True:
+            await asyncio.sleep(interval)
+            elapsed += interval
+
+            if timeout is not None and elapsed >= timeout:
+                raise TimeoutError(
+                    f"No change detected on {model.__name__} "
+                    f"with pk={pk_value!r} within {timeout}s"
+                )
+
+            instance = await _reload()
+
+            if instance is None:
+                raise NotFoundError(
+                    f"{model.__name__} with pk={pk_value!r} was deleted"
+                )
+
+            current = {col: getattr(instance, col) for col in watch_cols}
+            if current != initial:
+                return instance
+    finally:
+        await watcher.close()

src/fastapi_toolsets/dependencies.py

@@ -0,0 +1,147 @@
+"""Dependency factories for FastAPI routes."""
+
+import inspect
+import typing
+from collections.abc import Callable
+from typing import Any, cast
+
+from fastapi import Depends
+from fastapi.params import Depends as DependsClass
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from .crud import CrudFactory
+from .types import ModelType, SessionDependency
+
+__all__ = ["BodyDependency", "PathDependency"]
+
+
+def _unwrap_session_dep(session_dep: SessionDependency) -> Callable[..., Any]:
+    """Extract the plain callable from ``Annotated[AsyncSession, Depends(fn)]`` if needed."""
+    if typing.get_origin(session_dep) is typing.Annotated:
+        for arg in typing.get_args(session_dep)[1:]:
+            if isinstance(arg, DependsClass):
+                return arg.dependency
+    return session_dep
+
+
+def PathDependency(
+    model: type[ModelType],
+    field: Any,
+    *,
+    session_dep: SessionDependency,
+    param_name: str | None = None,
+) -> ModelType:
+    """Create a dependency that fetches a DB object from a path parameter.
+
+    Args:
+        model: SQLAlchemy model class
+        field: Model field to filter by (e.g., User.id)
+        session_dep: Session dependency function (e.g., get_db)
+        param_name: Path parameter name (defaults to model_field, e.g., user_id)
+
+    Returns:
+        A Depends() instance that resolves to the model instance
+
+    Raises:
+        NotFoundError: If no matching record is found
+
+    Example:
+        ```python
+        UserDep = PathDependency(User, User.id, session_dep=get_db)
+
+        @router.get("/user/{id}")
+        async def get(
+            user: User = UserDep,
+        ): ...
+        ```
+    """
+    session_callable = _unwrap_session_dep(session_dep)
+    crud = CrudFactory(model)
+    name = (
+        param_name
+        if param_name is not None
+        else f"{model.__name__.lower()}_{field.key}"
+    )
+    python_type = field.type.python_type
+
+    async def dependency(
+        session: AsyncSession = Depends(session_callable), **kwargs: Any
+    ) -> ModelType:
+        value = kwargs[name]
+        return await crud.get(session, filters=[field == value])
+
+    dependency.__signature__ = inspect.Signature(  # ty:ignore[unresolved-attribute]
+        parameters=[
+            inspect.Parameter(
+                name, inspect.Parameter.KEYWORD_ONLY, annotation=python_type
+            ),
+            inspect.Parameter(
+                "session",
+                inspect.Parameter.KEYWORD_ONLY,
+                annotation=AsyncSession,
+                default=Depends(session_callable),
+            ),
+        ]
+    )
+
+    return cast(ModelType, Depends(cast(Callable[..., ModelType], dependency)))
+
+
+def BodyDependency(
+    model: type[ModelType],
+    field: Any,
+    *,
+    session_dep: SessionDependency,
+    body_field: str,
+) -> ModelType:
+    """Create a dependency that fetches a DB object from a body field.
+
+    Args:
+        model: SQLAlchemy model class
+        field: Model field to filter by (e.g., User.id)
+        session_dep: Session dependency function (e.g., get_db)
+        body_field: Name of the field in the request body
+
+    Returns:
+        A Depends() instance that resolves to the model instance
+
+    Raises:
+        NotFoundError: If no matching record is found
+
+    Example:
+        ```python
+        UserDep = BodyDependency(
+            User, User.ctfd_id, session_dep=get_db, body_field="user_id"
+        )
+
+        @router.post("/assign")
+        async def assign(
+            user: User = UserDep,
+        ): ...
+        ```
+    """
+    session_callable = _unwrap_session_dep(session_dep)
+    crud = CrudFactory(model)
+    python_type = field.type.python_type
+
+    async def dependency(
+        session: AsyncSession = Depends(session_callable), **kwargs: Any
+    ) -> ModelType:
+        value = kwargs[body_field]
+        return await crud.get(session, filters=[field == value])
+
+    dependency.__signature__ = inspect.Signature(  # ty:ignore[unresolved-attribute]
+        parameters=[
+            inspect.Parameter(
+                body_field, inspect.Parameter.KEYWORD_ONLY, annotation=python_type
+            ),
+            inspect.Parameter(
+                "session",
+                inspect.Parameter.KEYWORD_ONLY,
+                annotation=AsyncSession,
+                default=Depends(session_callable),
+            ),
+        ]
+    )
+
+    return cast(ModelType, Depends(cast(Callable[..., ModelType], dependency)))

src/fastapi_toolsets/exceptions/__init__.py

@@ -0,0 +1,37 @@
+"""Standardized API exceptions and error response handlers."""
+
+from .exceptions import (
+    ApiError,
+    ApiException,
+    ConflictError,
+    ForbiddenError,
+    InvalidFacetFilterError,
+    InvalidOrderFieldError,
+    InvalidSearchColumnError,
+    LockTimeoutError,
+    NoSearchableFieldsError,
+    NotFoundError,
+    PoolExhaustedError,
+    UnauthorizedError,
+    UnsupportedFacetTypeError,
+    generate_error_responses,
+)
+from .handler import init_exceptions_handlers
+
+__all__ = [
+    "ApiError",
+    "ApiException",
+    "ConflictError",
+    "ForbiddenError",
+    "InvalidFacetFilterError",
+    "InvalidOrderFieldError",
+    "InvalidSearchColumnError",
+    "LockTimeoutError",
+    "NoSearchableFieldsError",
+    "NotFoundError",
+    "PoolExhaustedError",
+    "UnauthorizedError",
+    "UnsupportedFacetTypeError",
+    "generate_error_responses",
+    "init_exceptions_handlers",
+]

src/fastapi_toolsets/exceptions/exceptions.py

@@ -0,0 +1,296 @@
+"""Custom exceptions with standardized API error responses."""
+
+from typing import Any, ClassVar
+
+from ..schemas import ApiError, ErrorResponse, ResponseStatus
+
+
+class ApiException(Exception):
+    """Base exception for API errors with structured response."""
+
+    api_error: ClassVar[ApiError]
+
+    def __init_subclass__(cls, abstract: bool = False, **kwargs: Any) -> None:
+        super().__init_subclass__(**kwargs)
+        if not abstract and not hasattr(cls, "api_error"):
+            raise TypeError(
+                f"{cls.__name__} must define an 'api_error' class attribute. "
+                "Pass abstract=True when creating intermediate base classes."
+            )
+
+    def __init__(
+        self,
+        detail: str | None = None,
+        *,
+        desc: str | None = None,
+        data: Any = None,
+    ) -> None:
+        """Initialize the exception.
+
+        Args:
+            detail: Optional human-readable message
+            desc: Optional per-instance override for the ``description`` field
+                in the HTTP response body.
+            data: Optional per-instance override for the ``data`` field in the
+                HTTP response body.
+        """
+        updates: dict[str, Any] = {}
+        if detail is not None:
+            updates["msg"] = detail
+        if desc is not None:
+            updates["desc"] = desc
+        if data is not None:
+            updates["data"] = data
+        if updates:
+            object.__setattr__(
+                self, "api_error", self.__class__.api_error.model_copy(update=updates)
+            )
+        super().__init__(self.api_error.msg)
+
+
+class UnauthorizedError(ApiException):
+    """HTTP 401 - User is not authenticated."""
+
+    api_error = ApiError(
+        code=401,
+        msg="Unauthorized",
+        desc="Authentication credentials were missing or invalid.",
+        err_code="AUTH-401",
+    )
+
+
+class ForbiddenError(ApiException):
+    """HTTP 403 - User lacks required permissions."""
+
+    api_error = ApiError(
+        code=403,
+        msg="Forbidden",
+        desc="You do not have permission to access this resource.",
+        err_code="AUTH-403",
+    )
+
+
+class NotFoundError(ApiException):
+    """HTTP 404 - Resource not found."""
+
+    api_error = ApiError(
+        code=404,
+        msg="Not Found",
+        desc="The requested resource was not found.",
+        err_code="RES-404",
+    )
+
+
+class ConflictError(ApiException):
+    """HTTP 409 - Resource conflict."""
+
+    api_error = ApiError(
+        code=409,
+        msg="Conflict",
+        desc="The request conflicts with the current state of the resource.",
+        err_code="RES-409",
+    )
+
+
+class NoSearchableFieldsError(ApiException):
+    """Raised when search is requested but no searchable fields are available."""
+
+    api_error = ApiError(
+        code=400,
+        msg="No Searchable Fields",
+        desc="No searchable fields configured for this resource.",
+        err_code="SEARCH-400",
+    )
+
+    def __init__(self, model: type) -> None:
+        """Initialize the exception.
+
+        Args:
+            model: The model class that has no searchable fields configured.
+        """
+        self.model = model
+        super().__init__(
+            desc=(
+                f"No searchable fields found for model '{model.__name__}'. "
+                "Provide 'search_fields' parameter or set 'searchable_fields' on the CRUD class."
+            )
+        )
+
+
+class InvalidFacetFilterError(ApiException):
+    """Raised when filter_by contains a key not declared in facet_fields."""
+
+    api_error = ApiError(
+        code=400,
+        msg="Invalid Facet Filter",
+        desc="One or more filter_by keys are not declared as facet fields.",
+        err_code="FACET-400",
+    )
+
+    def __init__(self, key: str, valid_keys: set[str]) -> None:
+        """Initialize the exception.
+
+        Args:
+            key: The unknown filter key provided by the caller.
+            valid_keys: Set of valid keys derived from the declared facet_fields.
+        """
+        self.key = key
+        self.valid_keys = valid_keys
+        super().__init__(
+            desc=(
+                f"'{key}' is not a declared facet field. "
+                f"Valid keys: {sorted(valid_keys) or 'none — set facet_fields on the CRUD class'}."
+            )
+        )
+
+
+class UnsupportedFacetTypeError(ApiException):
+    """Raised when a facet field has a column type not supported by filter_by."""
+
+    api_error = ApiError(
+        code=400,
+        msg="Unsupported Facet Type",
+        desc="The column type is not supported for facet filtering.",
+        err_code="FACET-TYPE-400",
+    )
+
+    def __init__(self, key: str, col_type: str) -> None:
+        """Initialize the exception.
+
+        Args:
+            key: The facet field key.
+            col_type: The unsupported column type name.
+        """
+        self.key = key
+        self.col_type = col_type
+        super().__init__(
+            desc=(
+                f"Facet field '{key}' has unsupported column type '{col_type}'. "
+                f"Supported types: String, Integer, Numeric, Boolean, "
+                f"Date, DateTime, Time, Enum, Uuid, ARRAY."
+            )
+        )
+
+
+class InvalidSearchColumnError(ApiException):
+    """Raised when search_column is not one of the configured searchable fields."""
+
+    api_error = ApiError(
+        code=400,
+        msg="Invalid Search Column",
+        desc="The requested search column is not a configured searchable field.",
+        err_code="SEARCH-COL-400",
+    )
+
+    def __init__(self, column: str, valid_columns: list[str]) -> None:
+        """Initialize the exception.
+
+        Args:
+            column: The unknown search column provided by the caller.
+            valid_columns: List of valid search column keys.
+        """
+        self.column = column
+        self.valid_columns = valid_columns
+        super().__init__(
+            desc=(
+                f"'{column}' is not a searchable column. "
+                f"Valid columns: {valid_columns}."
+            )
+        )
+
+
+class InvalidOrderFieldError(ApiException):
+    """Raised when order_by contains a field not in the allowed order fields."""
+
+    api_error = ApiError(
+        code=422,
+        msg="Invalid Order Field",
+        desc="The requested order field is not allowed for this resource.",
+        err_code="SORT-422",
+    )
+
+    def __init__(self, field: str, valid_fields: list[str]) -> None:
+        """Initialize the exception.
+
+        Args:
+            field: The unknown order field provided by the caller.
+            valid_fields: List of valid field names.
+        """
+        self.field = field
+        self.valid_fields = valid_fields
+        super().__init__(
+            desc=f"'{field}' is not an allowed order field. Valid fields: {valid_fields}."
+        )
+
+
+class PoolExhaustedError(ApiException):
+    """HTTP 503 - Database connection pool is exhausted."""
+
+    api_error = ApiError(
+        code=503,
+        msg="Service Unavailable",
+        desc=(
+            "The database connection pool is exhausted. "
+            "Too many concurrent requests are holding connections. "
+            "Retry shortly or contact support if the issue persists."
+        ),
+        err_code="DB-503-POOL",
+    )
+
+
+class LockTimeoutError(ApiException):
+    """HTTP 503 - A database lock could not be acquired within the timeout."""
+
+    api_error = ApiError(
+        code=503,
+        msg="Service Unavailable",
+        desc=(
+            "A database lock could not be acquired within the allowed timeout. "
+            "The resource is under heavy contention. Retry shortly."
+        ),
+        err_code="DB-503-LOCK",
+    )
+
+
+def generate_error_responses(
+    *errors: type[ApiException],
+) -> dict[int | str, dict[str, Any]]:
+    """Generate OpenAPI response documentation for exceptions.
+
+    Args:
+        *errors: Exception classes that inherit from ApiException.
+
+    Returns:
+        Dict suitable for FastAPI's ``responses`` parameter.
+    """
+    responses: dict[int | str, dict[str, Any]] = {}
+
+    for error in errors:
+        api_error = error.api_error
+        code = api_error.code
+
+        if code not in responses:
+            responses[code] = {
+                "model": ErrorResponse,
+                "description": api_error.msg,
+                "content": {
+                    "application/json": {
+                        "examples": {},
+                    }
+                },
+            }
+
+        responses[code]["content"]["application/json"]["examples"][
+            api_error.err_code
+        ] = {
+            "summary": api_error.msg,
+            "value": {
+                "data": api_error.data,
+                "status": ResponseStatus.FAIL.value,
+                "message": api_error.msg,
+                "description": api_error.desc,
+                "error_code": api_error.err_code,
+            },
+        }
+
+    return responses

src/fastapi_toolsets/exceptions/handler.py

@@ -0,0 +1,179 @@
+"""Exception handlers for FastAPI applications."""
+
+from collections.abc import Callable
+from typing import Any
+
+from fastapi import FastAPI, Request, Response, status
+from fastapi.exceptions import (
+    HTTPException,
+    RequestValidationError,
+    ResponseValidationError,
+)
+from fastapi.responses import JSONResponse
+
+from ..schemas import ErrorResponse, ResponseStatus
+from .exceptions import ApiException
+
+_VALIDATION_LOCATION_PARAMS: frozenset[str] = frozenset(
+    {"body", "query", "path", "header", "cookie"}
+)
+
+
+def init_exceptions_handlers(app: FastAPI) -> FastAPI:
+    """Register exception handlers and custom OpenAPI schema on a FastAPI app.
+
+    Args:
+        app: FastAPI application instance.
+
+    Returns:
+        The same FastAPI instance (for chaining).
+    """
+    _register_exception_handlers(app)
+    _original_openapi = app.openapi
+    app.openapi = lambda: _patched_openapi(app, _original_openapi)  # type: ignore[method-assign]  # ty:ignore[invalid-assignment]
+    return app
+
+
+def _register_exception_handlers(app: FastAPI) -> None:
+    """Register all exception handlers on a FastAPI application."""
+
+    @app.exception_handler(ApiException)
+    async def api_exception_handler(request: Request, exc: ApiException) -> Response:
+        """Handle custom API exceptions with structured response."""
+        api_error = exc.api_error
+        error_response = ErrorResponse(
+            data=api_error.data,
+            message=api_error.msg,
+            description=api_error.desc,
+            error_code=api_error.err_code,
+        )
+        return JSONResponse(
+            status_code=api_error.code,
+            content=error_response.model_dump(),
+        )
+
+    @app.exception_handler(HTTPException)
+    async def http_exception_handler(request: Request, exc: HTTPException) -> Response:
+        """Handle Starlette/FastAPI HTTPException with a consistent error format."""
+        detail = exc.detail if isinstance(exc.detail, str) else "HTTP Error"
+        error_response = ErrorResponse(
+            message=detail,
+            error_code=f"HTTP-{exc.status_code}",
+        )
+        return JSONResponse(
+            status_code=exc.status_code,
+            content=error_response.model_dump(),
+            headers=getattr(exc, "headers", None),
+        )
+
+    @app.exception_handler(RequestValidationError)
+    async def request_validation_handler(
+        request: Request, exc: RequestValidationError
+    ) -> Response:
+        """Handle Pydantic request validation errors (422)."""
+        return _format_validation_error(exc)
+
+    @app.exception_handler(ResponseValidationError)
+    async def response_validation_handler(
+        request: Request, exc: ResponseValidationError
+    ) -> Response:
+        """Handle Pydantic response validation errors (422)."""
+        return _format_validation_error(exc)
+
+    @app.exception_handler(Exception)
+    async def generic_exception_handler(request: Request, exc: Exception) -> Response:
+        """Handle all unhandled exceptions with a generic 500 response."""
+        error_response = ErrorResponse(
+            message="Internal Server Error",
+            description="An unexpected error occurred. Please try again later.",
+            error_code="SERVER-500",
+        )
+        return JSONResponse(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            content=error_response.model_dump(),
+        )
+
+
+def _format_validation_error(
+    exc: RequestValidationError | ResponseValidationError,
+) -> JSONResponse:
+    """Format validation errors into a structured response."""
+    errors = exc.errors()
+    formatted_errors = []
+
+    for error in errors:
+        locs = error["loc"]
+        if locs and locs[0] in _VALIDATION_LOCATION_PARAMS:
+            locs = locs[1:]
+        field_path = ".".join(str(loc) for loc in locs)
+        formatted_errors.append(
+            {
+                "field": field_path or "root",
+                "message": error.get("msg", ""),
+                "type": error.get("type", ""),
+            }
+        )
+
+    error_response = ErrorResponse(
+        data={"errors": formatted_errors},
+        message="Validation Error",
+        description=f"{len(formatted_errors)} validation error(s) detected",
+        error_code="VAL-422",
+    )
+
+    return JSONResponse(
+        status_code=status.HTTP_422_UNPROCESSABLE_CONTENT,
+        content=error_response.model_dump(),
+    )
+
+
+def _patched_openapi(
+    app: FastAPI, original_openapi: Callable[[], dict[str, Any]]
+) -> dict[str, Any]:
+    """Generate the OpenAPI schema and replace default 422 responses.
+
+    Args:
+        app: FastAPI application instance.
+        original_openapi: The previous ``app.openapi`` callable to delegate to.
+
+    Returns:
+        Patched OpenAPI schema dict.
+    """
+    if app.openapi_schema:
+        return app.openapi_schema
+
+    openapi_schema = original_openapi()
+
+    for path_data in openapi_schema.get("paths", {}).values():
+        for operation in path_data.values():
+            if isinstance(operation, dict) and "422" in operation.get("responses", {}):
+                operation["responses"]["422"] = {
+                    "description": "Validation Error",
+                    "content": {
+                        "application/json": {
+                            "examples": {
+                                "VAL-422": {
+                                    "summary": "Validation Error",
+                                    "value": {
+                                        "data": {
+                                            "errors": [
+                                                {
+                                                    "field": "field_name",
+                                                    "message": "value is not valid",
+                                                    "type": "value_error",
+                                                }
+                                            ]
+                                        },
+                                        "status": ResponseStatus.FAIL.value,
+                                        "message": "Validation Error",
+                                        "description": "1 validation error(s) detected",
+                                        "error_code": "VAL-422",
+                                    },
+                                }
+                            }
+                        }
+                    },
+                }
+
+    app.openapi_schema = openapi_schema
+    return app.openapi_schema

src/fastapi_toolsets/fixtures/__init__.py

@@ -0,0 +1,34 @@
+"""Fixture system for seeding databases with dependency resolution."""
+
+from typing import TYPE_CHECKING
+
+from .enum import Context, LoadStrategy
+
+if TYPE_CHECKING:
+    from .registry import FixtureRegistry
+    from .utils import load_fixtures, load_fixtures_by_context
+
+__all__ = [
+    "Context",
+    "FixtureRegistry",
+    "LoadStrategy",
+    "load_fixtures",
+    "load_fixtures_by_context",
+]
+
+_LAZY = {
+    "FixtureRegistry": ".registry",
+    "load_fixtures": ".utils",
+    "load_fixtures_by_context": ".utils",
+}
+
+
+def __getattr__(name: str):
+    module_name = _LAZY.get(name)
+    if module_name is None:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    import importlib
+
+    module = importlib.import_module(module_name, __name__)
+    return getattr(module, name)

src/fastapi_toolsets/fixtures/enum.py

@@ -0,0 +1,32 @@
+"""Enums for fixture loading strategies and contexts."""
+
+from enum import Enum
+
+
+class LoadStrategy(str, Enum):
+    """Strategy for loading fixtures into the database."""
+
+    INSERT = "insert"
+    """Insert new records. Fails if record already exists."""
+
+    MERGE = "merge"
+    """Insert or update based on primary key (SQLAlchemy merge)."""
+
+    SKIP_EXISTING = "skip_existing"
+    """Insert only if record doesn't exist (based on primary key)."""
+
+
+class Context(str, Enum):
+    """Predefined fixture contexts."""
+
+    BASE = "base"
+    """Base fixtures loaded in all environments."""
+
+    PRODUCTION = "production"
+    """Production-only fixtures."""
+
+    DEVELOPMENT = "development"
+    """Development fixtures."""
+
+    TESTING = "testing"
+    """Test fixtures."""

src/fastapi_toolsets/fixtures/registry.py

@@ -0,0 +1,363 @@
+"""Fixture system with dependency management and context support."""
+
+from collections.abc import Callable, Sequence
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Any, cast
+
+from sqlalchemy.orm import DeclarativeBase
+
+from .enum import Context
+
+
+def _normalize_contexts(
+    contexts: list[str | Enum] | tuple[str | Enum, ...],
+) -> list[str]:
+    """Convert a sequence of any Enum subclass and/or plain strings to a list of strings."""
+    return [c.value if isinstance(c, Enum) else c for c in contexts]
+
+
+def _context_filter_values(contexts: tuple[str | Enum, ...]) -> set[str]:
+    """Normalize *contexts* for filtering, always including Context.BASE."""
+    return set(_normalize_contexts(contexts)) | {Context.BASE.value}
+
+
+@dataclass
+class Fixture:
+    """A fixture definition with metadata."""
+
+    name: str
+    func: Callable[[], Sequence[DeclarativeBase]]
+    depends_on: list[str] = field(default_factory=list)
+    contexts: list[str] = field(default_factory=lambda: [Context.BASE])
+
+
+class FixtureRegistry:
+    """Registry for managing fixtures with dependencies.
+
+    Example:
+        ```python
+        from fastapi_toolsets.fixtures import FixtureRegistry, Context
+
+        fixtures = FixtureRegistry()
+
+        @fixtures.register
+        def roles():
+            return [
+                Role(id=1, name="admin"),
+                Role(id=2, name="user"),
+            ]
+
+        @fixtures.register(depends_on=["roles"])
+        def users():
+            return [
+                User(id=1, username="admin", role_id=1),
+            ]
+
+        @fixtures.register(depends_on=["users"], contexts=[Context.TESTING])
+        def test_data():
+            return [
+                Post(id=1, title="Test", user_id=1),
+            ]
+        ```
+
+    Fixtures with the same name may be registered for **different** contexts.
+    When multiple contexts are loaded together, their instances are merged:
+
+        ```python
+        @fixtures.register(contexts=[Context.BASE])
+        def users():
+            return [User(id=1, username="admin")]
+
+        @fixtures.register(contexts=[Context.TESTING])
+        def users():
+            return [User(id=2, username="tester")]
+        ```
+    """
+
+    def __init__(
+        self,
+        contexts: list[str | Enum] | None = None,
+    ) -> None:
+        self._fixtures: dict[str, list[Fixture]] = {}
+        self._default_contexts: list[str] | None = (
+            _normalize_contexts(contexts) if contexts else None
+        )
+
+    def _validate_no_context_overlap(self, name: str, new_contexts: list[str]) -> None:
+        """Raise ``ValueError`` if any existing variant for *name* overlaps."""
+        existing_variants = self._fixtures.get(name, [])
+        new_set = set(new_contexts)
+        for variant in existing_variants:
+            if set(variant.contexts) & new_set:
+                raise ValueError(
+                    f"Fixture '{name}' already exists in the current registry "
+                    f"with overlapping contexts. Use distinct context sets for "
+                    f"each variant of the same fixture name."
+                )
+
+    def register(
+        self,
+        func: Callable[[], Sequence[DeclarativeBase]] | None = None,
+        *,
+        name: str | None = None,
+        depends_on: list[str] | None = None,
+        contexts: list[str | Enum] | None = None,
+    ) -> Callable[..., Any]:
+        """Register a fixture function.
+
+        Can be used as a decorator with or without arguments.
+
+        Args:
+            func: Fixture function returning list of model instances
+            name: Fixture name (defaults to function name)
+            depends_on: List of fixture names this depends on
+            contexts: List of contexts this fixture belongs to.  Both
+                :class:`Context` enum values and plain strings are accepted.
+
+        Example:
+            ```python
+            @fixtures.register
+            def roles():
+                return [Role(id=1, name="admin")]
+
+            @fixtures.register(depends_on=["roles"], contexts=[Context.TESTING])
+            def test_users():
+                return [User(id=1, username="test", role_id=1)]
+        """
+
+        def decorator(
+            fn: Callable[[], Sequence[DeclarativeBase]],
+        ) -> Callable[[], Sequence[DeclarativeBase]]:
+            fixture_name = name or cast(Any, fn).__name__
+            if contexts is not None:
+                fixture_contexts = _normalize_contexts(contexts)
+            elif self._default_contexts is not None:
+                fixture_contexts = self._default_contexts
+            else:
+                fixture_contexts = [Context.BASE.value]
+
+            self._validate_no_context_overlap(fixture_name, fixture_contexts)
+            self._fixtures.setdefault(fixture_name, []).append(
+                Fixture(
+                    name=fixture_name,
+                    func=fn,
+                    depends_on=depends_on or [],
+                    contexts=fixture_contexts,
+                )
+            )
+            return fn
+
+        if func is not None:
+            return decorator(func)
+        return decorator
+
+    def include_registry(self, registry: "FixtureRegistry") -> None:
+        """Include another `FixtureRegistry` in the same current `FixtureRegistry`.
+
+        Fixtures with the same name are allowed as long as their context sets
+        do not overlap.  Conflicting contexts raise :class:`ValueError`.
+
+        Args:
+            registry: The `FixtureRegistry` to include
+
+        Raises:
+            ValueError: If a fixture name already exists with overlapping contexts
+
+        Example:
+            ```python
+            registry = FixtureRegistry()
+            dev_registry = FixtureRegistry()
+
+            @dev_registry.register
+            def dev_data():
+                return [...]
+
+            registry.include_registry(registry=dev_registry)
+            ```
+        """
+        for name, variants in registry._fixtures.items():
+            for fixture in variants:
+                self._validate_no_context_overlap(name, fixture.contexts)
+                self._fixtures.setdefault(name, []).append(fixture)
+
+    def get(self, name: str) -> Fixture:
+        """Get a fixture by name.
+
+        Raises:
+            KeyError: If no fixture with *name* is registered.
+            ValueError: If the fixture has multiple context variants — use
+                :meth:`get_variants` in that case.
+        """
+        variants = self.get_variants(name)
+        if len(variants) > 1:
+            raise ValueError(
+                f"Fixture '{name}' has {len(variants)} context variants. "
+                f"Use get_variants('{name}') to retrieve them."
+            )
+        return variants[0]
+
+    def get_variants(self, name: str, *contexts: str | Enum) -> list[Fixture]:
+        """Return all registered variants for *name*, optionally filtered by context.
+
+        Args:
+            name: Fixture name.
+            *contexts: If given, only return variants whose context set
+                intersects with these values (:class:`Context.BASE` variants
+                are always included).  Both :class:`Context` enum values and
+                plain strings are accepted.
+
+        Returns:
+            List of matching :class:`Fixture` objects (may be empty when a
+            context filter is applied and nothing matches).
+
+        Raises:
+            KeyError: If no fixture with *name* is registered.
+        """
+        if name not in self._fixtures:
+            raise KeyError(f"Fixture '{name}' not found")
+        variants = self._fixtures[name]
+        if not contexts:
+            return list(variants)
+        context_values = _context_filter_values(contexts)
+        return [v for v in variants if set(v.contexts) & context_values]
+
+    def get_load_variants(self, name: str, *contexts: str | Enum) -> list[Fixture]:
+        """Return variants for *name* filtered by *contexts*.
+
+        Raises:
+            KeyError: If no fixture with *name* is registered.
+        """
+        variants = self.get_variants(name, *contexts)
+        if contexts and not variants:
+            return self.get_variants(name)
+        return variants
+
+    def get_all(self) -> list[Fixture]:
+        """Get all registered fixtures (all variants of all names)."""
+        return [f for variants in self._fixtures.values() for f in variants]
+
+    def get_dependencies(self, name: str) -> list[str]:
+        """Get the union of ``depends_on`` across all variants of *name*.
+
+        Raises:
+            KeyError: If no fixture named *name* is registered.
+        """
+        variants = self._fixtures.get(name)
+        if variants is None:
+            raise KeyError(f"Fixture '{name}' not found")
+
+        seen: set[str] = set()
+        deps: list[str] = []
+        for variant in variants:
+            for dep in variant.depends_on:
+                if dep not in seen:
+                    deps.append(dep)
+                    seen.add(dep)
+        return deps
+
+    def obj(self, name: str, attr_name: str, value: Any) -> DeclarativeBase:
+        """Get a model instance from a registered fixture by attribute value.
+
+        Args:
+            name: Fixture name to look up.
+            attr_name: Name of the attribute to match against.
+            value: Value to match.
+
+        Returns:
+            The first model instance where the attribute matches the given value.
+
+        Raises:
+            KeyError: If no fixture named *name* is registered.
+            StopIteration: If no matching object is found.
+        """
+        instances = (
+            obj for variant in self.get_variants(name) for obj in variant.func()
+        )
+        try:
+            return next(obj for obj in instances if getattr(obj, attr_name) == value)
+        except StopIteration:
+            raise StopIteration(
+                f"No object with {attr_name}={value} found in fixture '{name}'"
+            ) from None
+
+    def field(self, name: str, attr_name: str, value: Any, *, field: str = "id") -> Any:
+        """Get a single field value from a fixture object matched by an attribute.
+
+        Args:
+            name: Fixture name to look up.
+            attr_name: Name of the attribute to match against.
+            value: Value to match.
+            field: Attribute name to return from the matched object (default: ``"id"``).
+
+        Returns:
+            The value of ``field`` on the first matching model instance.
+
+        Raises:
+            KeyError: If no fixture named *name* is registered.
+            StopIteration: If no matching object is found.
+        """
+        return getattr(self.obj(name, attr_name, value), field)
+
+    def get_by_context(self, *contexts: str | Enum) -> list[Fixture]:
+        """Get fixtures for specific contexts."""
+        context_values = _context_filter_values(contexts)
+        return [
+            f
+            for variants in self._fixtures.values()
+            for f in variants
+            if set(f.contexts) & context_values
+        ]
+
+    def resolve_dependencies(self, *names: str) -> list[str]:
+        """Resolve fixture dependencies in topological order.
+
+        When a fixture name has multiple context variants, the union of all
+        variants' ``depends_on`` lists is used.
+
+        Args:
+            *names: Fixture names to resolve
+
+        Returns:
+            List of fixture names in load order (dependencies first)
+
+        Raises:
+            KeyError: If a fixture is not found
+            ValueError: If circular dependency detected
+        """
+        resolved: list[str] = []
+        visiting: set[str] = set()
+
+        def visit(name: str) -> None:
+            if name in resolved:
+                return
+            if name in visiting:
+                raise ValueError(f"Circular dependency detected: {name}")
+
+            visiting.add(name)
+            for dep in self.get_dependencies(name):
+                visit(dep)
+
+            visiting.remove(name)
+            resolved.append(name)
+
+        for name in names:
+            visit(name)
+
+        return resolved
+
+    def resolve_context_dependencies(self, *contexts: str | Enum) -> list[str]:
+        """Resolve all fixtures for contexts with dependencies.
+
+        Args:
+            *contexts: Contexts to load
+
+        Returns:
+            List of fixture names in load order
+        """
+        context_fixtures = self.get_by_context(*contexts)
+        # Deduplicate names while preserving first-seen order (a name can
+        # appear multiple times if it has variants in different contexts).
+        names = list(dict.fromkeys(f.name for f in context_fixtures))
+
+        return self.resolve_dependencies(*names)

src/fastapi_toolsets/fixtures/utils.py

@@ -0,0 +1,399 @@
+"""Fixture loading utilities for database seeding."""
+
+from collections.abc import Iterator
+from enum import Enum
+from typing import Any, cast
+
+from sqlalchemy import Table, select
+from sqlalchemy import inspect as sa_inspect
+from sqlalchemy.dialects.postgresql import insert as pg_insert
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase, selectinload
+from sqlalchemy.orm.interfaces import ExecutableOption, ORMOption
+
+from ..db import transaction
+from ..logger import get_logger
+from .enum import LoadStrategy
+from .registry import FixtureRegistry, _normalize_contexts
+
+logger = get_logger()
+
+
+def _instance_to_dict(instance: DeclarativeBase) -> dict[str, Any]:
+    """Extract column values from a model instance, skipping unset server-default columns."""
+    state = sa_inspect(instance)
+    state_dict = state.dict
+    result: dict[str, Any] = {}
+    for prop in state.mapper.column_attrs:
+        if prop.key not in state_dict:
+            continue
+        val = state_dict[prop.key]
+        if val is None:
+            col = prop.columns[0]
+
+            if (
+                col.server_default is not None
+                or (col.default is not None and col.default.is_callable)
+                or col.autoincrement is True
+            ):
+                continue
+        result[prop.key] = val
+    return result
+
+
+def _get_table_chain(model_cls: type[DeclarativeBase]) -> list[type[DeclarativeBase]]:
+    """Return [root, ..., model_cls] for joined-table inheritance, or [model_cls]."""
+    chain: list[type[DeclarativeBase]] = []
+    current = sa_inspect(model_cls)
+    while current is not None:
+        chain.append(current.class_)
+        current = current.inherits
+    chain.reverse()
+    seen: set[int] = set()
+    result: list[type[DeclarativeBase]] = []
+    for cls in chain:
+        tid = id(cls.__table__)
+        if tid not in seen:  # pragma: no branch
+            seen.add(tid)
+            result.append(cls)
+    return result
+
+
+def _instance_to_dict_for_cls(
+    instance: DeclarativeBase, cls: type[DeclarativeBase]
+) -> dict[str, Any]:
+    """Like _instance_to_dict but limited to columns belonging to cls's own table."""
+    own_cols = {col.key for col in cls.__table__.columns}
+    return {k: v for k, v in _instance_to_dict(instance).items() if k in own_cols}
+
+
+def _group_by_type(
+    instances: list[DeclarativeBase],
+) -> list[tuple[type[DeclarativeBase], list[DeclarativeBase]]]:
+    """Group instances by their concrete model class, preserving insertion order."""
+    groups: dict[type[DeclarativeBase], list[DeclarativeBase]] = {}
+    for instance in instances:
+        groups.setdefault(type(instance), []).append(instance)
+    return list(groups.items())
+
+
+def _group_by_column_set(
+    dicts: list[dict[str, Any]],
+    instances: list[DeclarativeBase],
+) -> list[tuple[list[dict[str, Any]], list[DeclarativeBase]]]:
+    """Group (dict, instance) pairs by their dict key sets."""
+    groups: dict[
+        frozenset[str], tuple[list[dict[str, Any]], list[DeclarativeBase]]
+    ] = {}
+    for d, inst in zip(dicts, instances):
+        key = frozenset(d)
+        if key not in groups:
+            groups[key] = ([], [])
+        groups[key][0].append(d)
+        groups[key][1].append(inst)
+    return list(groups.values())
+
+
+def _grouped_table_dicts(
+    model_cls: type[DeclarativeBase], instances: list[DeclarativeBase]
+) -> Iterator[
+    tuple[type[DeclarativeBase], list[dict[str, Any]], list[DeclarativeBase]]
+]:
+    """Yield (cls, group_dicts, group_instances) per table in the inheritance
+    chain and per column-set group, skipping empty groups.
+    """
+    for cls in _get_table_chain(model_cls):
+        dicts = [_instance_to_dict_for_cls(i, cls) for i in instances]
+        for group_dicts, group_instances in _group_by_column_set(dicts, instances):
+            if group_dicts and group_dicts[0]:  # pragma: no branch
+                yield cls, group_dicts, group_instances
+
+
+async def _batch_insert(
+    session: AsyncSession,
+    model_cls: type[DeclarativeBase],
+    instances: list[DeclarativeBase],
+) -> None:
+    """INSERT all instances, raises on conflict."""
+    for cls, group_dicts, group_instances in _grouped_table_dicts(model_cls, instances):
+        table = cast(Table, cls.__table__)
+        missing_pk_cols = [
+            col for col in table.primary_key.columns if col.key not in group_dicts[0]
+        ]
+        if not missing_pk_cols:
+            await session.execute(pg_insert(table), group_dicts)
+            continue
+        stmt = pg_insert(table).returning(
+            *missing_pk_cols, sort_by_parameter_order=True
+        )
+        result = await session.execute(stmt, group_dicts)
+        for inst, row in zip(group_instances, result):
+            for col, val in zip(missing_pk_cols, row):
+                setattr(inst, col.key, val)
+
+
+async def _batch_merge(
+    session: AsyncSession,
+    model_cls: type[DeclarativeBase],
+    instances: list[DeclarativeBase],
+) -> None:
+    """UPSERT: insert new rows, update existing ones with the provided values."""
+    for cls, group_dicts, _ in _grouped_table_dicts(model_cls, instances):
+        table = cast(Table, cls.__table__)
+        pk_names = [col.name for col in table.primary_key]
+        pk_names_set = set(pk_names)
+        own_col_keys = {col.key for col in table.columns}
+        non_pk_cols = [k for k in own_col_keys if k not in pk_names_set]
+
+        stmt = pg_insert(table).values(group_dicts)
+
+        inserted_keys = set(group_dicts[0])
+        update_cols = [col for col in non_pk_cols if col in inserted_keys]
+
+        if update_cols:
+            stmt = stmt.on_conflict_do_update(
+                index_elements=pk_names,
+                set_={col: stmt.excluded[col] for col in update_cols},
+            )
+        else:
+            stmt = stmt.on_conflict_do_nothing(index_elements=pk_names)
+
+        await session.execute(stmt)
+
+
+async def _batch_skip_existing(
+    session: AsyncSession,
+    model_cls: type[DeclarativeBase],
+    instances: list[DeclarativeBase],
+) -> list[DeclarativeBase]:
+    """INSERT only rows that do not already exist; return the inserted ones."""
+    if len(_get_table_chain(model_cls)) > 1:
+        loaded: list[DeclarativeBase] = []
+        for inst in instances:
+            pk = _get_primary_key(inst)
+            if pk is None or not await session.get(model_cls, pk):
+                session.add(inst)
+                loaded.append(inst)
+        await session.flush()
+        return loaded
+
+    mapper = model_cls.__mapper__
+    pk_names = [col.name for col in mapper.primary_key]
+
+    no_pk: list[DeclarativeBase] = []
+    with_pk_pairs: list[tuple[DeclarativeBase, Any]] = []
+    for inst in instances:
+        pk = _get_primary_key(inst)
+        if pk is None:
+            no_pk.append(inst)
+        else:
+            with_pk_pairs.append((inst, pk))
+
+    loaded = list(no_pk)
+    if no_pk:
+        no_pk_dicts = [_instance_to_dict(i) for i in no_pk]
+        for group_dicts, group_instances in _group_by_column_set(no_pk_dicts, no_pk):
+            stmt = pg_insert(cast(Table, model_cls.__table__)).returning(
+                *mapper.primary_key, sort_by_parameter_order=True
+            )
+            result = await session.execute(stmt, group_dicts)
+            for inst, row in zip(group_instances, result):
+                for col, val in zip(mapper.primary_key, row):
+                    setattr(inst, cast(str, col.key), val)
+
+    if with_pk_pairs:
+        with_pk = [i for i, _ in with_pk_pairs]
+        with_pk_dicts = [_instance_to_dict(i) for i in with_pk]
+        for group_dicts, group_insts in _group_by_column_set(with_pk_dicts, with_pk):
+            stmt = (
+                pg_insert(model_cls)
+                .values(group_dicts)
+                .on_conflict_do_nothing(index_elements=pk_names)
+            )
+            result = await session.execute(stmt.returning(*mapper.primary_key))
+            inserted_pks = {
+                row[0] if len(pk_names) == 1 else tuple(row) for row in result
+            }
+            loaded.extend(
+                inst
+                for inst, pk in zip(
+                    group_insts, [_get_primary_key(i) for i in group_insts]
+                )
+                if pk in inserted_pks
+            )
+
+    return loaded
+
+
+def _relationship_load_options(model: type[DeclarativeBase]) -> list[ExecutableOption]:
+    """Build selectinload options for all direct relationships on a model."""
+    return [
+        selectinload(getattr(model, rel.key)) for rel in model.__mapper__.relationships
+    ]
+
+
+async def _reload_with_relationships(
+    session: AsyncSession,
+    instances: list[DeclarativeBase],
+    load_options: list[ExecutableOption],
+) -> list[DeclarativeBase]:
+    """Reload instances in a single bulk query with relationship eager-loading."""
+    model = type(instances[0])
+    mapper = model.__mapper__
+    pk_cols = mapper.primary_key
+
+    if len(pk_cols) == 1:
+        pk_key = cast(str, pk_cols[0].key)
+        pk_attr = getattr(model, pk_key)
+        pks = [getattr(inst, pk_key) for inst in instances]
+        result = await session.execute(
+            select(model).where(pk_attr.in_(pks)).options(*load_options)
+        )
+        by_pk = {getattr(row, pk_key): row for row in result.unique().scalars()}
+        return [by_pk[pk] for pk in pks]
+
+    # Composite PK: fall back to per-instance reload
+    reloaded: list[DeclarativeBase] = []
+    for instance in instances:
+        pk = _get_primary_key(instance)
+        refreshed = await session.get(
+            model,
+            pk,
+            options=cast(list[ORMOption], load_options),
+            populate_existing=True,
+        )
+        if refreshed is not None:  # pragma: no branch
+            reloaded.append(refreshed)
+    return reloaded
+
+
+async def _refresh_loaded(
+    session: AsyncSession, instances: list[DeclarativeBase]
+) -> list[DeclarativeBase]:
+    """Re-select freshly written rows, eager-loading relationships."""
+    if not instances:
+        return []
+    refreshed: list[DeclarativeBase | None] = [None] * len(instances)
+    for model_cls, group in _group_by_type(instances):
+        positions = [i for i, inst in enumerate(instances) if type(inst) is model_cls]
+        load_options = _relationship_load_options(model_cls)
+        for pos, new in zip(
+            positions, await _reload_with_relationships(session, group, load_options)
+        ):
+            refreshed[pos] = new
+    return cast(list[DeclarativeBase], refreshed)
+
+
+async def _load_ordered(
+    session: AsyncSession,
+    registry: FixtureRegistry,
+    ordered_names: list[str],
+    strategy: LoadStrategy,
+    contexts: tuple[str, ...] | None = None,
+) -> dict[str, list[DeclarativeBase]]:
+    """Load fixtures in order using batch Core INSERT statements."""
+    results: dict[str, list[DeclarativeBase]] = {}
+
+    for name in ordered_names:
+        variants = (
+            registry.get_load_variants(name, *contexts)
+            if contexts is not None
+            else registry.get_variants(name)
+        )
+
+        if not variants:  # pragma: no cover
+            results[name] = []
+            continue
+
+        instances = [inst for v in variants for inst in v.func()]
+
+        if not instances:
+            results[name] = []
+            continue
+
+        model_name = type(instances[0]).__name__
+        loaded: list[DeclarativeBase] = []
+
+        async with transaction(session):
+            for model_cls, group in _group_by_type(instances):
+                match strategy:
+                    case LoadStrategy.INSERT:
+                        await _batch_insert(session, model_cls, group)
+                        loaded.extend(group)
+                    case LoadStrategy.MERGE:
+                        await _batch_merge(session, model_cls, group)
+                        loaded.extend(group)
+                    case LoadStrategy.SKIP_EXISTING:
+                        inserted = await _batch_skip_existing(session, model_cls, group)
+                        loaded.extend(inserted)
+                    case _:  # pragma: no cover
+                        pass
+
+            loaded = await _refresh_loaded(session, loaded)
+
+        results[name] = loaded
+        logger.info("Loaded fixture '%s': %d %s(s)", name, len(loaded), model_name)
+
+    return results
+
+
+def _get_primary_key(instance: DeclarativeBase) -> Any | None:
+    """Get the primary key value of a model instance."""
+    mapper = instance.__class__.__mapper__
+    pk_cols = mapper.primary_key
+
+    if len(pk_cols) == 1:
+        return getattr(instance, pk_cols[0].name, None)
+
+    pk_values = tuple(getattr(instance, col.name, None) for col in pk_cols)
+    if all(v is not None for v in pk_values):
+        return pk_values
+    return None
+
+
+async def load_fixtures(
+    session: AsyncSession,
+    registry: FixtureRegistry,
+    *names: str,
+    strategy: LoadStrategy = LoadStrategy.MERGE,
+) -> dict[str, list[DeclarativeBase]]:
+    """Load specific fixtures by name with dependencies.
+
+    All context variants of each requested fixture are loaded and merged.
+
+    Args:
+        session: Database session
+        registry: Fixture registry
+        *names: Fixture names to load (dependencies auto-resolved)
+        strategy: How to handle existing records
+
+    Returns:
+        Dict mapping fixture names to loaded instances
+    """
+    ordered = registry.resolve_dependencies(*names)
+    return await _load_ordered(session, registry, ordered, strategy)
+
+
+async def load_fixtures_by_context(
+    session: AsyncSession,
+    registry: FixtureRegistry,
+    *contexts: str | Enum,
+    strategy: LoadStrategy = LoadStrategy.MERGE,
+) -> dict[str, list[DeclarativeBase]]:
+    """Load all fixtures for specific contexts.
+
+    Args:
+        session: Database session
+        registry: Fixture registry
+        *contexts: Contexts to load (e.g., ``Context.TESTING``, or plain
+            strings for custom contexts)
+        strategy: How to handle existing records
+
+    Returns:
+        Dict mapping fixture names to loaded instances
+    """
+    context_strings = tuple(_normalize_contexts(contexts))
+    ordered = registry.resolve_context_dependencies(*contexts)
+    return await _load_ordered(
+        session, registry, ordered, strategy, contexts=context_strings
+    )

src/fastapi_toolsets/logger.py

@@ -0,0 +1,98 @@
+"""Logging configuration for FastAPI applications and CLI tools."""
+
+import logging
+import sys
+from typing import Literal
+
+__all__ = ["LogLevel", "configure_logging", "get_logger"]
+
+DEFAULT_FORMAT = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+UVICORN_LOGGERS = ("uvicorn", "uvicorn.access", "uvicorn.error")
+
+LogLevel = Literal["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
+
+
+def configure_logging(
+    level: LogLevel | int = "INFO",
+    fmt: str = DEFAULT_FORMAT,
+    logger_name: str | None = None,
+) -> logging.Logger:
+    """Configure logging with a stdout handler and consistent format.
+
+    Sets up a :class:`~logging.StreamHandler` writing to stdout with the
+    given format and level.  Also configures the uvicorn loggers so that
+    FastAPI access logs use the same format.
+
+    Calling this function multiple times is safe -- existing handlers are
+    replaced rather than duplicated.
+
+    Args:
+        level: Log level (e.g. ``"DEBUG"``, ``"INFO"``, or ``logging.DEBUG``).
+        fmt: Log format string.  Defaults to
+            ``"%(asctime)s - %(name)s - %(levelname)s - %(message)s"``.
+        logger_name: Logger name to configure.  ``None`` (the default)
+            configures the root logger so all loggers inherit the settings.
+
+    Returns:
+        The configured Logger instance.
+
+    Example:
+        ```python
+        from fastapi_toolsets.logger import configure_logging
+
+        logger = configure_logging("DEBUG")
+        logger.info("Application started")
+        ```
+    """
+    formatter = logging.Formatter(fmt)
+
+    handler = logging.StreamHandler(sys.stdout)
+    handler.setFormatter(formatter)
+
+    logger = logging.getLogger(logger_name)
+    logger.handlers.clear()
+    logger.addHandler(handler)
+    logger.setLevel(level)
+
+    for name in UVICORN_LOGGERS:
+        uv_logger = logging.getLogger(name)
+        uv_logger.handlers.clear()
+        uv_logger.addHandler(handler)
+        uv_logger.setLevel(level)
+
+    return logger
+
+
+_SENTINEL = object()
+
+
+def get_logger(name: str | None = _SENTINEL) -> logging.Logger:  # type: ignore[assignment]  # ty:ignore[invalid-parameter-default]
+    """Return a logger with the given *name*.
+
+    A thin convenience wrapper around :func:`logging.getLogger` that keeps
+    logging imports consistent across the codebase.
+
+    When called without arguments, the caller's ``__name__`` is used
+    automatically, so ``get_logger()`` in a module is equivalent to
+    ``logging.getLogger(__name__)``.  Pass ``None`` explicitly to get the
+    root logger.
+
+    Args:
+        name: Logger name.  Defaults to the caller's ``__name__``.
+            Pass ``None`` to get the root logger.
+
+    Returns:
+        A Logger instance.
+
+    Example:
+        ```python
+        from fastapi_toolsets.logger import get_logger
+
+        logger = get_logger()          # uses caller's __name__
+        logger = get_logger("myapp")   # explicit name
+        logger = get_logger(None)      # root logger
+        ```
+    """
+    if name is _SENTINEL:
+        name = sys._getframe(1).f_globals.get("__name__")
+    return logging.getLogger(name)

src/fastapi_toolsets/metrics/__init__.py

@@ -0,0 +1,21 @@
+"""Prometheus metrics integration for FastAPI applications."""
+
+from typing import Any
+
+from .registry import Metric, MetricsRegistry
+
+try:
+    from .handler import init_metrics
+except ImportError:
+
+    def init_metrics(*_args: Any, **_kwargs: Any) -> None:
+        from .._imports import require_extra
+
+        require_extra(package="prometheus_client", extra="metrics")
+
+
+__all__ = [
+    "Metric",
+    "MetricsRegistry",
+    "init_metrics",
+]

src/fastapi_toolsets/metrics/handler.py

@@ -0,0 +1,81 @@
+"""Prometheus metrics endpoint for FastAPI applications."""
+
+import inspect
+import os
+
+from fastapi import FastAPI
+from fastapi.responses import Response
+from prometheus_client import (
+    CONTENT_TYPE_LATEST,
+    CollectorRegistry,
+    generate_latest,
+    multiprocess,
+)
+
+from ..logger import get_logger
+from .registry import MetricsRegistry
+
+logger = get_logger()
+
+
+def _is_multiprocess() -> bool:
+    """Check if prometheus multi-process mode is enabled."""
+    return "PROMETHEUS_MULTIPROC_DIR" in os.environ
+
+
+def init_metrics(
+    app: FastAPI,
+    registry: MetricsRegistry,
+    *,
+    path: str = "/metrics",
+) -> FastAPI:
+    """Register a Prometheus ``/metrics`` endpoint on a FastAPI app.
+
+    Args:
+        app: FastAPI application instance.
+        registry: A :class:`MetricsRegistry` containing providers and collectors.
+        path: URL path for the metrics endpoint (default ``/metrics``).
+
+    Returns:
+        The same FastAPI instance (for chaining).
+
+    Example:
+        ```python
+        from fastapi import FastAPI
+        from fastapi_toolsets.metrics import MetricsRegistry, init_metrics
+
+        metrics = MetricsRegistry()
+        app = FastAPI()
+        init_metrics(app, registry=metrics)
+        ```
+    """
+    for provider in registry.get_providers():
+        logger.debug("Initialising metric provider '%s'", provider.name)
+        registry._instances[provider.name] = provider.func()
+
+    # Partition collectors and cache env check at startup — both are stable for the app lifetime.
+    async_collectors = [
+        c for c in registry.get_collectors() if inspect.iscoroutinefunction(c.func)
+    ]
+    sync_collectors = [
+        c for c in registry.get_collectors() if not inspect.iscoroutinefunction(c.func)
+    ]
+    multiprocess_mode = _is_multiprocess()
+
+    @app.get(path, include_in_schema=False)
+    async def metrics_endpoint() -> Response:
+        for collector in sync_collectors:
+            collector.func()
+        for collector in async_collectors:
+            await collector.func()
+
+        if multiprocess_mode:
+            prom_registry = CollectorRegistry()
+            multiprocess.MultiProcessCollector(prom_registry)
+            output = generate_latest(prom_registry)
+        else:
+            output = generate_latest()
+
+        return Response(content=output, media_type=CONTENT_TYPE_LATEST)
+
+    return app

src/fastapi_toolsets/metrics/registry.py

@@ -0,0 +1,104 @@
+"""Metrics registry with decorator-based registration."""
+
+from collections.abc import Callable
+from dataclasses import dataclass, field
+from typing import Any, cast
+
+from ..logger import get_logger
+
+logger = get_logger()
+
+
+@dataclass
+class Metric:
+    """A metric definition with metadata."""
+
+    name: str
+    func: Callable[..., Any]
+    collect: bool = field(default=False)
+
+
+class MetricsRegistry:
+    """Registry for managing Prometheus metric providers and collectors."""
+
+    def __init__(self) -> None:
+        self._metrics: dict[str, Metric] = {}
+        self._instances: dict[str, Any] = {}
+
+    def register(
+        self,
+        func: Callable[..., Any] | None = None,
+        *,
+        name: str | None = None,
+        collect: bool = False,
+    ) -> Callable[..., Any]:
+        """Register a metric provider or collector function.
+
+        Can be used as a decorator with or without arguments.
+
+        Args:
+            func: The metric function to register.
+            name: Metric name (defaults to function name).
+            collect: If ``True``, the function is called on every scrape.
+                If ``False`` (default), called once at init time.
+        """
+
+        def decorator(fn: Callable[..., Any]) -> Callable[..., Any]:
+            metric_name = name or cast(Any, fn).__name__
+            self._metrics[metric_name] = Metric(
+                name=metric_name,
+                func=fn,
+                collect=collect,
+            )
+            return fn
+
+        if func is not None:
+            return decorator(func)
+        return decorator
+
+    def get(self, name: str) -> Any:
+        """Return the metric instance created by a provider.
+
+        Args:
+            name: The metric name (defaults to the provider function name).
+
+        Raises:
+            KeyError: If the metric name is unknown or ``init_metrics`` has not
+                been called yet.
+        """
+        if name not in self._instances:
+            if name in self._metrics:
+                raise KeyError(
+                    f"Metric '{name}' exists but has not been initialized yet. "
+                    "Ensure init_metrics() has been called before accessing metric instances."
+                )
+            raise KeyError(f"Unknown metric '{name}'.")
+        return self._instances[name]
+
+    def include_registry(self, registry: "MetricsRegistry") -> None:
+        """Include another :class:`MetricsRegistry` into this one.
+
+        Args:
+            registry: The registry to merge in.
+
+        Raises:
+            ValueError: If a metric name already exists in the current registry.
+        """
+        for metric_name, definition in registry._metrics.items():
+            if metric_name in self._metrics:
+                raise ValueError(
+                    f"Metric '{metric_name}' already exists in the current registry"
+                )
+            self._metrics[metric_name] = definition
+
+    def get_all(self) -> list[Metric]:
+        """Get all registered metric definitions."""
+        return list(self._metrics.values())
+
+    def get_providers(self) -> list[Metric]:
+        """Get metric providers (called once at init)."""
+        return [m for m in self._metrics.values() if not m.collect]
+
+    def get_collectors(self) -> list[Metric]:
+        """Get collectors (called on each scrape)."""
+        return [m for m in self._metrics.values() if m.collect]

src/fastapi_toolsets/models/__init__.py

@@ -0,0 +1,21 @@
+"""SQLAlchemy model mixins for common column patterns."""
+
+from .columns import (
+    CreatedAtMixin,
+    TimestampMixin,
+    UpdatedAtMixin,
+    UUIDMixin,
+    UUIDv7Mixin,
+)
+from .watched import EventSession, ModelEvent, listens_for
+
+__all__ = [
+    "CreatedAtMixin",
+    "EventSession",
+    "ModelEvent",
+    "TimestampMixin",
+    "UUIDMixin",
+    "UUIDv7Mixin",
+    "UpdatedAtMixin",
+    "listens_for",
+]

src/fastapi_toolsets/models/columns.py

@@ -0,0 +1,50 @@
+"""SQLAlchemy column mixins for common column patterns."""
+
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, Uuid, text
+from sqlalchemy.orm import Mapped, mapped_column
+
+
+class UUIDMixin:
+    """Mixin that adds a UUID primary key auto-generated by the database."""
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        Uuid,
+        primary_key=True,
+        server_default=text("gen_random_uuid()"),
+    )
+
+
+class UUIDv7Mixin:
+    """Mixin that adds a UUIDv7 primary key auto-generated by the database."""
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        Uuid,
+        primary_key=True,
+        server_default=text("uuidv7()"),
+    )
+
+
+class CreatedAtMixin:
+    """Mixin that adds a ``created_at`` timestamp column."""
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=text("clock_timestamp()"),
+    )
+
+
+class UpdatedAtMixin:
+    """Mixin that adds an ``updated_at`` timestamp column."""
+
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=text("clock_timestamp()"),
+        onupdate=text("clock_timestamp()"),
+    )
+
+
+class TimestampMixin(CreatedAtMixin, UpdatedAtMixin):
+    """Mixin that combines ``created_at`` and ``updated_at`` timestamp columns."""

src/fastapi_toolsets/models/watched.py

@@ -0,0 +1,304 @@
+"""Field-change monitoring via SQLAlchemy session events."""
+
+import inspect
+from collections.abc import Callable
+from enum import Enum
+from typing import Any
+
+from sqlalchemy import event, select, tuple_
+from sqlalchemy import inspect as sa_inspect
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm.attributes import set_committed_value as _sa_set_committed_value
+
+from ..logger import get_logger
+
+_logger = get_logger()
+
+
+class ModelEvent(str, Enum):
+    """Event types dispatched by :class:`EventSession`."""
+
+    CREATE = "create"
+    DELETE = "delete"
+    UPDATE = "update"
+
+
+_CALLBACK_ERROR_MSG = "Event callback raised an unhandled exception"
+_SESSION_CREATES = "_ft_creates"
+_SESSION_DELETES = "_ft_deletes"
+_SESSION_UPDATES = "_ft_updates"
+_DEFERRED_STRATEGY_KEY = (("deferred", True), ("instrument", True))
+_EVENT_HANDLERS: dict[tuple[type, ModelEvent], list[Callable[..., Any]]] = {}
+_HANDLER_CACHE: dict[tuple[type, ModelEvent], list[Callable[..., Any]]] = {}
+
+
+def _invalidate_caches() -> None:
+    """Clear lookup caches after handler registration."""
+    _HANDLER_CACHE.clear()
+
+
+def listens_for(
+    model_class: type,
+    event_types: list[ModelEvent] | None = None,
+) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
+    """Register a callback for one or more model lifecycle events.
+
+    Args:
+        model_class: The SQLAlchemy model class to listen on.
+        event_types: List of :class:`ModelEvent` values to listen for.
+            Defaults to all event types.
+    """
+    evs = event_types if event_types is not None else list(ModelEvent)
+
+    def decorator(fn: Callable[..., Any]) -> Callable[..., Any]:
+        for ev in evs:
+            _EVENT_HANDLERS.setdefault((model_class, ev), []).append(fn)
+        _invalidate_caches()
+        return fn
+
+    return decorator
+
+
+def _get_handlers(cls: type, ev: ModelEvent) -> list[Callable[..., Any]]:
+    """Return registered handlers for *cls* and *ev*, walking the MRO."""
+    key = (cls, ev)
+    try:
+        return _HANDLER_CACHE[key]
+    except KeyError:
+        handlers: list[Callable[..., Any]] = []
+        for klass in cls.__mro__:
+            handlers.extend(_EVENT_HANDLERS.get((klass, ev), []))
+        _HANDLER_CACHE[key] = handlers
+        return handlers
+
+
+def _snapshot_column_attrs(obj: Any) -> dict[str, Any]:
+    """Read currently-loaded column values into a plain dict."""
+    state = sa_inspect(obj)  # InstanceState
+    state_dict = state.dict
+    snapshot: dict[str, Any] = {}
+    for prop in state.mapper.column_attrs:
+        if prop.key in state_dict:
+            snapshot[prop.key] = state_dict[prop.key]
+        elif (  # pragma: no cover
+            not state.expired
+            and prop.strategy_key != _DEFERRED_STRATEGY_KEY
+            and all(
+                col.nullable
+                and col.server_default is None
+                and col.server_onupdate is None
+                for col in prop.columns
+            )
+        ):
+            snapshot[prop.key] = None
+    return snapshot
+
+
+def _get_watched_fields(cls: type) -> tuple[str, ...] | None:
+    """Return the watched fields for *cls*."""
+    fields = getattr(cls, "__watched_fields__", None)
+    if fields is not None and (
+        not isinstance(fields, tuple) or not all(isinstance(f, str) for f in fields)
+    ):
+        raise TypeError(
+            f"{cls.__name__}.__watched_fields__ must be a tuple[str, ...], "
+            f"got {type(fields).__name__}"
+        )
+    return fields
+
+
+def _upsert_changes(
+    pending: dict[int, tuple[Any, dict[str, dict[str, Any]]]],
+    obj: Any,
+    changes: dict[str, dict[str, Any]],
+) -> None:
+    """Insert or merge *changes* into *pending* for *obj*."""
+    key = id(obj)
+    if key in pending:
+        existing = pending[key][1]
+        for field, change in changes.items():
+            if field in existing:
+                existing[field]["new"] = change["new"]
+            else:
+                existing[field] = change
+    else:
+        pending[key] = (obj, changes)
+
+
+@event.listens_for(AsyncSession.sync_session_class, "after_flush")
+def _after_flush(session: Any, flush_context: Any) -> None:
+    # New objects: capture reference. Attributes will be refreshed after commit.
+    for obj in session.new:
+        if _get_handlers(type(obj), ModelEvent.CREATE):
+            session.info.setdefault(_SESSION_CREATES, []).append(obj)
+
+    # Deleted objects: snapshot now while attributes are still loaded.
+    for obj in session.deleted:
+        if _get_handlers(type(obj), ModelEvent.DELETE):
+            snapshot = _snapshot_column_attrs(obj)
+            session.info.setdefault(_SESSION_DELETES, []).append((obj, snapshot))
+
+    # Dirty objects: read old/new from SQLAlchemy attribute history.
+    for obj in session.dirty:
+        if not _get_handlers(type(obj), ModelEvent.UPDATE):
+            continue
+
+        watched = _get_watched_fields(type(obj))
+        changes: dict[str, dict[str, Any]] = {}
+
+        inst_attrs = sa_inspect(obj).attrs
+        attrs = (
+            ((field, inst_attrs[field]) for field in watched)
+            if watched is not None
+            else ((s.key, s) for s in inst_attrs)
+        )
+        for field, attr_state in attrs:
+            history = attr_state.history
+            if history.has_changes() and history.deleted:
+                changes[field] = {
+                    "old": history.deleted[0],
+                    "new": history.added[0] if history.added else None,
+                }
+
+        if changes:
+            _upsert_changes(
+                session.info.setdefault(_SESSION_UPDATES, {}),
+                obj,
+                changes,
+            )
+
+
+@event.listens_for(AsyncSession.sync_session_class, "after_rollback")
+def _after_rollback(session: Any) -> None:
+    if session.in_transaction():
+        return
+    session.info.pop(_SESSION_CREATES, None)
+    session.info.pop(_SESSION_DELETES, None)
+    session.info.pop(_SESSION_UPDATES, None)
+
+
+async def _invoke_callback(
+    fn: Callable[..., Any],
+    obj: Any,
+    event_type: ModelEvent,
+    changes: dict[str, dict[str, Any]] | None,
+) -> None:
+    """Call *fn* and await the result if it is awaitable."""
+    result = fn(obj, event_type, changes)
+    if inspect.isawaitable(result):
+        await result
+
+
+async def _batch_reload(
+    session: AsyncSession, model: type, pk_tuples: list[tuple[Any, ...]]
+) -> None:
+    """Re-populate all rows of *model* identified by *pk_tuples* in one round trip."""
+    pk_cols = sa_inspect(model, raiseerr=True).primary_key
+    where = (
+        pk_cols[0].in_([pk[0] for pk in pk_tuples])
+        if len(pk_cols) == 1
+        else tuple_(*pk_cols).in_(pk_tuples)
+    )
+    q = select(model).where(where).execution_options(populate_existing=True)
+    await session.execute(q)
+
+
+class EventSession(AsyncSession):
+    """AsyncSession subclass that dispatches lifecycle callbacks after commit."""
+
+    async def commit(self) -> None:
+        await super().commit()
+
+        creates: list[Any] = self.info.pop(_SESSION_CREATES, [])
+        deletes: list[tuple[Any, dict[str, Any]]] = self.info.pop(_SESSION_DELETES, [])
+        field_changes: dict[int, tuple[Any, dict[str, dict[str, Any]]]] = self.info.pop(
+            _SESSION_UPDATES, {}
+        )
+
+        if not creates and not deletes and not field_changes:
+            return
+
+        # Suppress transient objects (created + deleted in same transaction).
+        if creates and deletes:
+            created_ids = {id(o) for o in creates}
+            deleted_ids = {id(o) for o, _ in deletes}
+            transient_ids = created_ids & deleted_ids
+            if transient_ids:
+                creates = [o for o in creates if id(o) not in transient_ids]
+                deletes = [(o, s) for o, s in deletes if id(o) not in transient_ids]
+                field_changes = {
+                    k: v for k, v in field_changes.items() if k not in transient_ids
+                }
+
+        # Suppress updates for deleted objects (row is gone, refresh would fail).
+        if deletes and field_changes:
+            deleted_ids = {id(o) for o, _ in deletes}
+            field_changes = {
+                k: v for k, v in field_changes.items() if k not in deleted_ids
+            }
+
+        # Suppress updates for newly created objects (CREATE-only semantics).
+        if creates and field_changes:
+            create_ids = {id(o) for o in creates}
+            field_changes = {
+                k: v for k, v in field_changes.items() if k not in create_ids
+            }
+
+        # Resolve reloadable state up front and group PKs by model type so
+        # the post-commit reload is one query per type instead of one
+        # session.get() per object.
+        create_items: list[Any] = []
+        update_items: list[tuple[Any, dict[str, dict[str, Any]]]] = []
+        pk_by_type: dict[type, list[tuple[Any, ...]]] = {}
+
+        for obj in creates:
+            state = sa_inspect(obj, raiseerr=False)
+            if state is None or state.detached or state.transient:  # pragma: no cover
+                continue
+            create_items.append(obj)
+            pk_by_type.setdefault(type(obj), []).append(state.key[1])
+
+        for obj, changes in field_changes.values():
+            state = sa_inspect(obj, raiseerr=False)
+            if state is None or state.detached or state.transient:  # pragma: no cover
+                continue
+            update_items.append((obj, changes))
+            pk_by_type.setdefault(type(obj), []).append(state.key[1])
+
+        for model, pk_tuples in pk_by_type.items():
+            try:
+                await _batch_reload(self, model, pk_tuples)
+            except Exception as exc:
+                _logger.error(_CALLBACK_ERROR_MSG, exc_info=exc)
+
+        # Dispatch CREATE callbacks.
+        for obj in create_items:
+            try:
+                for handler in _get_handlers(type(obj), ModelEvent.CREATE):
+                    await _invoke_callback(handler, obj, ModelEvent.CREATE, None)
+            except Exception as exc:
+                _logger.error(_CALLBACK_ERROR_MSG, exc_info=exc)
+
+        # Dispatch DELETE callbacks (restore snapshot; row is gone).
+        for obj, snapshot in deletes:
+            try:
+                for key, value in snapshot.items():
+                    _sa_set_committed_value(obj, key, value)
+                for handler in _get_handlers(type(obj), ModelEvent.DELETE):
+                    await _invoke_callback(handler, obj, ModelEvent.DELETE, None)
+            except Exception as exc:
+                _logger.error(_CALLBACK_ERROR_MSG, exc_info=exc)
+
+        # Dispatch UPDATE callbacks.
+        for obj, changes in update_items:
+            try:
+                for handler in _get_handlers(type(obj), ModelEvent.UPDATE):
+                    await _invoke_callback(handler, obj, ModelEvent.UPDATE, changes)
+            except Exception as exc:
+                _logger.error(_CALLBACK_ERROR_MSG, exc_info=exc)
+
+    async def rollback(self) -> None:
+        await super().rollback()
+        self.info.pop(_SESSION_CREATES, None)
+        self.info.pop(_SESSION_DELETES, None)
+        self.info.pop(_SESSION_UPDATES, None)

src/fastapi_toolsets/pytest/__init__.py

@@ -0,0 +1,30 @@
+"""Pytest helpers for FastAPI testing: sessions, clients, and fixtures."""
+
+try:
+    from .plugin import register_fixtures
+except ImportError:
+    from .._imports import require_extra
+
+    require_extra(package="pytest", extra="pytest")
+
+try:
+    from .utils import (
+        cleanup_tables,
+        create_async_client,
+        create_db_session,
+        create_worker_database,
+        worker_database_url,
+    )
+except ImportError:
+    from .._imports import require_extra
+
+    require_extra(package="httpx", extra="pytest")
+
+__all__ = [
+    "cleanup_tables",
+    "create_async_client",
+    "create_db_session",
+    "create_worker_database",
+    "register_fixtures",
+    "worker_database_url",
+]

src/fastapi_toolsets/pytest/plugin.py

@@ -0,0 +1,128 @@
+"""Pytest plugin for using FixtureRegistry fixtures in tests."""
+
+from collections.abc import Sequence
+from typing import Any
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase
+
+from ..fixtures import FixtureRegistry, LoadStrategy
+from ..fixtures.utils import _get_primary_key, _load_ordered, _refresh_loaded
+
+
+def register_fixtures(
+    registry: FixtureRegistry,
+    namespace: dict[str, Any],
+    *,
+    prefix: str = "fixture_",
+    session_fixture: str = "db_session",
+    strategy: LoadStrategy = LoadStrategy.MERGE,
+) -> list[str]:
+    """Register pytest fixtures from a FixtureRegistry.
+
+    Automatically creates pytest fixtures for each fixture in the registry.
+    Dependencies are resolved via pytest fixture dependencies.
+
+    Args:
+        registry: The FixtureRegistry containing fixtures
+        namespace: The module's globals() dict to add fixtures to
+        prefix: Prefix for generated fixture names (default: "fixture_")
+        session_fixture: Name of the db session fixture (default: "db_session")
+        strategy: Loading strategy for fixtures (default: MERGE)
+
+    Returns:
+        List of created fixture names
+
+    Example:
+        ```python
+        # conftest.py
+        from app.fixtures import fixtures
+        from fastapi_toolsets.pytest_plugin import register_fixtures
+
+        register_fixtures(fixtures, globals())
+
+        # Creates fixtures like:
+        # - fixture_roles
+        # - fixture_users (depends on fixture_roles if users depends on roles)
+        # - fixture_posts (depends on fixture_users if posts depends on users)
+        ```
+    """
+    created_fixtures: list[str] = []
+
+    for fixture in registry.get_all():
+        fixture_name = f"{prefix}{fixture.name}"
+
+        # Build list of pytest fixture dependencies
+        pytest_deps = [session_fixture]
+        for dep in registry.get_dependencies(fixture.name):
+            pytest_deps.append(f"{prefix}{dep}")
+
+        # Create the fixture function
+        fixture_func = _create_fixture_function(
+            registry=registry,
+            fixture_name=fixture.name,
+            dependencies=pytest_deps,
+            strategy=strategy,
+        )
+
+        # Apply pytest.fixture decorator
+        decorated = pytest.fixture(fixture_func)
+
+        # Add to namespace
+        namespace[fixture_name] = decorated
+        created_fixtures.append(fixture_name)
+
+    return created_fixtures
+
+
+def _create_fixture_function(
+    registry: FixtureRegistry,
+    fixture_name: str,
+    dependencies: list[str],
+    strategy: LoadStrategy,
+) -> Any:
+    """Create a fixture function with the correct signature.
+
+    The function signature must include all dependencies as parameters
+    for pytest (and pytest-anyio's fixture chaining) to resolve them
+    correctly — dynamic resolution via ``request.getfixturevalue`` deadlocks
+    when called from inside an already-running async fixture.
+    """
+    fixture_def = registry.get(fixture_name)
+
+    async def fixture_func(**kwargs: Any) -> Sequence[DeclarativeBase]:
+        session: AsyncSession = kwargs[dependencies[0]]
+        result = (await _load_ordered(session, registry, [fixture_name], strategy))[
+            fixture_name
+        ]
+
+        if strategy is LoadStrategy.SKIP_EXISTING:
+            # _load_ordered only returns newly-inserted rows for this
+            # strategy (the CLI seeding contract). A test fixture should
+            # still hand back the full, usable set including rows that
+            # were already present, so top up with those.
+            declared = list(fixture_def.func())
+            result_pks = {_get_primary_key(r) for r in result}
+            missing = [
+                d
+                for d in declared
+                if (pk := _get_primary_key(d)) is not None and pk not in result_pks
+            ]
+            if missing:
+                result = result + await _refresh_loaded(session, missing)
+
+        return result
+
+    # Update function signature to include dependencies
+    # This is needed for pytest to inject the right fixtures
+    params = ", ".join(dependencies)
+    code = f"async def {fixture_name}_fixture({params}):\n    return await _impl({', '.join(f'{d}={d}' for d in dependencies)})"
+
+    local_ns: dict[str, Any] = {"_impl": fixture_func}
+    exec(code, local_ns)  # noqa: S102
+
+    created_func = local_ns[f"{fixture_name}_fixture"]
+    created_func.__doc__ = f"Load {fixture_name} fixture data."
+
+    return created_func

src/fastapi_toolsets/pytest/utils.py

@@ -0,0 +1,309 @@
+"""Pytest helper utilities for FastAPI testing."""
+
+import os
+from collections.abc import AsyncGenerator, Callable
+from contextlib import asynccontextmanager
+from typing import Any
+
+from httpx import ASGITransport, AsyncClient
+from sqlalchemy import text
+from sqlalchemy.engine import URL, make_url
+from sqlalchemy.ext.asyncio import (
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+from sqlalchemy.orm import DeclarativeBase
+
+from ..db.testing import cleanup_tables, create_database
+from ..models.watched import EventSession
+
+
+def _get_xdist_worker(default_test_db: str) -> str:
+    """Return the pytest-xdist worker name, or *default_test_db* when not running under xdist.
+
+    Reads the ``PYTEST_XDIST_WORKER`` environment variable that xdist sets
+    automatically in each worker process (e.g. ``"gw0"``, ``"gw1"``).
+    When xdist is not installed or not active, the variable is absent and
+    *default_test_db* is returned instead.
+
+    Args:
+        default_test_db: Fallback value returned when ``PYTEST_XDIST_WORKER``
+            is not set.
+    """
+    return os.environ.get("PYTEST_XDIST_WORKER", default_test_db)
+
+
+def worker_database_url(
+    database_url: str,
+    default_test_db: str,
+    *,
+    prefix: str | None = None,
+) -> str:
+    """Derive a per-worker database URL for pytest-xdist parallel runs.
+
+    Sets the database name to the worker name so each xdist worker operates
+    on its own database.  When not running under xdist, *default_test_db* is
+    used instead.  When *prefix* is provided, the name becomes
+    ``{prefix}_{worker}``.
+
+    The worker name is read from the ``PYTEST_XDIST_WORKER`` environment
+    variable (set automatically by xdist in each worker process).
+
+    Args:
+        database_url: Original database connection URL.
+        default_test_db: Suffix appended to the database name when
+            ``PYTEST_XDIST_WORKER`` is not set.
+        prefix: Optional prefix prepended to the worker name
+            (e.g. ``"test"`` → ``"test_gw0"``).  Without it, the database
+            name is just the worker name (e.g. ``"gw0"``).
+
+    Returns:
+        A database URL with a worker- or default-specific database name.
+    """
+    worker = _get_xdist_worker(default_test_db=default_test_db)
+
+    url = make_url(database_url)
+    db_name = f"{prefix}_{worker}" if prefix else worker
+    url = url.set(database=db_name)
+    return url.render_as_string(hide_password=False)
+
+
+@asynccontextmanager
+async def create_worker_database(
+    database_url: str,
+    default_test_db: str = "test_db",
+    *,
+    prefix: str | None = None,
+    server_url: str | None = None,
+) -> AsyncGenerator[str, None]:
+    """Create and drop a per-worker database for pytest-xdist isolation.
+
+    Derives a worker-specific database URL using :func:`worker_database_url`,
+    then delegates to :func:`~fastapi_toolsets.db.create_database` to create
+    and drop it.  Intended for use as a **session-scoped** fixture.
+
+    When running under xdist the database name is suffixed with the worker
+    name (e.g. ``_gw0``).  Otherwise it is suffixed with *default_test_db*.
+
+    Args:
+        database_url: Original database connection URL (used as the base for
+            the worker database name).
+        default_test_db: Suffix appended to the database name when
+            ``PYTEST_XDIST_WORKER`` is not set. Defaults to ``"test_db"``.
+        prefix: Optional prefix prepended to the worker name
+            (e.g. ``prefix="test"`` → ``"test_gw0"``).  Without it, the
+            database name is just the worker name (e.g. ``"gw0"``).
+        server_url: URL used for server-level DDL (must point to an existing
+            database on the same server).  Defaults to *database_url* with the
+            database omitted, letting asyncpg fall back to the username.
+
+    Yields:
+        The worker-specific database URL.
+
+    Example:
+        ```python
+        from fastapi_toolsets.pytest import create_worker_database, create_db_session
+
+        DATABASE_URL = "postgresql+asyncpg://postgres:postgres@localhost/myapp"
+
+        @pytest.fixture(scope="session")
+        async def worker_db_url():
+            async with create_worker_database(DATABASE_URL) as url:
+                yield url
+
+        @pytest.fixture
+        async def db_session(worker_db_url):
+            async with create_db_session(
+                worker_db_url, Base, cleanup=True
+            ) as session:
+                yield session
+        ```
+    """
+    worker_url = worker_database_url(
+        database_url=database_url, default_test_db=default_test_db, prefix=prefix
+    )
+    worker_db_name = make_url(worker_url).database
+    assert worker_db_name is not None
+
+    _parsed = make_url(database_url)
+    _server_url = server_url or URL.create(
+        drivername=_parsed.drivername,
+        username=_parsed.username,
+        password=_parsed.password,
+        host=_parsed.host,
+        port=_parsed.port,
+        query=_parsed.query,
+    ).render_as_string(hide_password=False)
+
+    engine = create_async_engine(_server_url, isolation_level="AUTOCOMMIT")
+    try:
+        async with engine.connect() as conn:
+            await conn.execute(
+                text(f"DROP DATABASE IF EXISTS {worker_db_name} WITH (FORCE)")
+            )
+        await create_database(db_name=worker_db_name, server_url=_server_url)
+
+        yield worker_url
+
+        async with engine.connect() as conn:
+            await conn.execute(
+                text(f"DROP DATABASE IF EXISTS {worker_db_name} WITH (FORCE)")
+            )
+    finally:
+        await engine.dispose()
+
+
+@asynccontextmanager
+async def create_async_client(
+    app: Any,
+    base_url: str = "http://test",
+    dependency_overrides: dict[Callable[..., Any], Callable[..., Any]] | None = None,
+    **kwargs: Any,
+) -> AsyncGenerator[AsyncClient, None]:
+    """Create an async httpx client for testing FastAPI applications.
+
+    Args:
+        app: FastAPI application instance.
+        base_url: Base URL for requests. Defaults to "http://test".
+        dependency_overrides: Optional mapping of original dependencies to
+            their test replacements. Applied via ``app.dependency_overrides``
+            before yielding and cleaned up after.
+        **kwargs: Additional keyword arguments forwarded to
+            :class:`httpx.AsyncClient` (e.g. ``headers``, ``cookies``,
+            ``auth``, ``timeout``).
+
+    Yields:
+        An AsyncClient configured for the app.
+
+    Example:
+        ```python
+        from fastapi import FastAPI
+        from fastapi_toolsets.pytest import create_async_client
+
+        app = FastAPI()
+
+        @pytest.fixture
+        async def client():
+            async with create_async_client(app) as c:
+                yield c
+
+        async def test_endpoint(client: AsyncClient):
+            response = await client.get("/health")
+            assert response.status_code == 200
+        ```
+
+    Example with dependency overrides:
+        ```python
+        from fastapi_toolsets.pytest import create_async_client, create_db_session
+        from app.db import get_db
+
+        @pytest.fixture
+        async def db_session():
+            async with create_db_session(DATABASE_URL, Base, cleanup=True) as session:
+                yield session
+
+        @pytest.fixture
+        async def client(db_session):
+            async def override():
+                yield db_session
+
+            async with create_async_client(
+                app, dependency_overrides={get_db: override}
+            ) as c:
+                yield c
+        ```
+    """
+    if dependency_overrides:
+        app.dependency_overrides.update(dependency_overrides)
+
+    transport = ASGITransport(app=app)
+    try:
+        async with AsyncClient(
+            transport=transport, base_url=base_url, **kwargs
+        ) as client:
+            yield client
+    finally:
+        if dependency_overrides:
+            for key in dependency_overrides:
+                app.dependency_overrides.pop(key, None)
+
+
+@asynccontextmanager
+async def create_db_session(
+    database_url: str,
+    base: type[DeclarativeBase],
+    *,
+    echo: bool = False,
+    expire_on_commit: bool = False,
+    drop_tables: bool = True,
+    cleanup: bool = False,
+    engine_kwargs: dict[str, Any] | None = None,
+    session_kwargs: dict[str, Any] | None = None,
+) -> AsyncGenerator[AsyncSession, None]:
+    """Create a database session for testing.
+
+    Creates tables before yielding the session and optionally drops them after.
+    Each call creates a fresh engine and session for test isolation.
+
+    Args:
+        database_url: Database connection URL (e.g., "postgresql+asyncpg://...").
+        base: SQLAlchemy DeclarativeBase class containing model metadata.
+        echo: Enable SQLAlchemy query logging. Defaults to False.
+        expire_on_commit: Expire objects after commit. Defaults to False.
+        drop_tables: Drop tables after test. Defaults to True.
+        cleanup: Truncate all tables after test using
+            :func:`cleanup_tables`. Defaults to False.
+        engine_kwargs: Additional keyword arguments forwarded to
+            :func:`sqlalchemy.ext.asyncio.create_async_engine`
+            (e.g. ``pool_size``, ``connect_args``).
+        session_kwargs: Additional keyword arguments forwarded to
+            :class:`sqlalchemy.ext.asyncio.async_sessionmaker`
+            (e.g. ``autoflush``, ``class_``).
+
+    Yields:
+        An AsyncSession ready for database operations.
+
+    Example:
+        ```python
+        from fastapi_toolsets.pytest import create_db_session
+        from app.models import Base
+
+        DATABASE_URL = "postgresql+asyncpg://user:pass@localhost/test_db"
+
+        @pytest.fixture
+        async def db_session():
+            async with create_db_session(
+                DATABASE_URL, Base, cleanup=True
+            ) as session:
+                yield session
+
+        async def test_create_user(db_session: AsyncSession):
+            user = User(name="test")
+            db_session.add(user)
+            await db_session.commit()
+        ```
+    """
+    engine = create_async_engine(database_url, echo=echo, **(engine_kwargs or {}))
+
+    try:
+        async with engine.begin() as conn:
+            await conn.run_sync(base.metadata.create_all)
+
+        session_maker = async_sessionmaker(
+            engine,
+            expire_on_commit=expire_on_commit,
+            class_=EventSession,
+            **(session_kwargs or {}),
+        )
+        async with session_maker() as session:
+            yield session
+
+            if cleanup:
+                await cleanup_tables(session=session, base=base)
+
+        if drop_tables:
+            async with engine.begin() as conn:
+                await conn.run_sync(base.metadata.drop_all)
+    finally:
+        await engine.dispose()

src/fastapi_toolsets/schemas.py

@@ -0,0 +1,206 @@
+"""Base Pydantic schemas for API responses."""
+
+import math
+from enum import Enum
+from typing import Annotated, Any, ClassVar, Generic, Literal, TypeVar
+
+from pydantic import BaseModel, ConfigDict, Field, computed_field
+
+from .types import DataT
+
+__all__ = [
+    "ApiError",
+    "CursorPaginatedResponse",
+    "CursorPagination",
+    "ErrorResponse",
+    "OffsetPaginatedResponse",
+    "OffsetPagination",
+    "PaginatedResponse",
+    "PaginationType",
+    "PydanticBase",
+    "Response",
+    "ResponseStatus",
+]
+
+
+class PydanticBase(BaseModel):
+    """Base class for all Pydantic models with common configuration."""
+
+    model_config: ClassVar[ConfigDict] = ConfigDict(
+        from_attributes=True,
+        validate_assignment=True,
+    )
+
+
+class ResponseStatus(str, Enum):
+    """Standard API response status."""
+
+    SUCCESS = "SUCCESS"
+    FAIL = "FAIL"
+
+
+class ApiError(PydanticBase):
+    """Structured API error definition.
+
+    Used to define standard error responses with consistent format.
+
+    Attributes:
+        code: HTTP status code
+        msg: Short error message
+        desc: Detailed error description
+        err_code: Application-specific error code (e.g., "AUTH-401")
+    """
+
+    code: int
+    msg: str
+    desc: str
+    err_code: str
+    data: Any | None = None
+
+
+class BaseResponse(PydanticBase):
+    """Base response structure for all API responses.
+
+    Attributes:
+        status: SUCCESS or FAIL
+        message: Human-readable message
+        error_code: Error code if status is FAIL, None otherwise
+    """
+
+    status: ResponseStatus = ResponseStatus.SUCCESS
+    message: str = "Success"
+    error_code: str | None = None
+
+
+class Response(BaseResponse, Generic[DataT]):
+    """Generic API response with data payload.
+
+    Example:
+        ```python
+        Response[UserRead](data=user, message="User retrieved")
+        ```
+    """
+
+    data: DataT | None = None
+
+
+class ErrorResponse(BaseResponse):
+    """Error response with additional description field.
+
+    Used for error responses that need more context.
+    """
+
+    status: ResponseStatus = ResponseStatus.FAIL
+    description: str | None = None
+    data: Any | None = None
+
+
+class OffsetPagination(PydanticBase):
+    """Pagination metadata for offset-based list responses.
+
+    Attributes:
+        total_count: Total number of items across all pages.
+            ``None`` when ``include_total=False``.
+        items_per_page: Number of items per page
+        page: Current page number (1-indexed)
+        has_more: Whether there are more pages
+        pages: Total number of pages
+    """
+
+    total_count: int | None
+    items_per_page: int
+    page: int
+    has_more: bool
+
+    @computed_field
+    @property
+    def pages(self) -> int | None:
+        """Total number of pages, or ``None`` when ``total_count`` is unknown."""
+        if self.total_count is None:
+            return None
+        if self.items_per_page == 0:
+            return 0
+        return math.ceil(self.total_count / self.items_per_page)
+
+
+class CursorPagination(PydanticBase):
+    """Pagination metadata for cursor-based list responses.
+
+    Attributes:
+        next_cursor: Encoded cursor for the next page, or None on the last page.
+        prev_cursor: Encoded cursor for the previous page, or None on the first page.
+        items_per_page: Number of items requested per page.
+        has_more: Whether there is at least one more page after this one.
+    """
+
+    next_cursor: str | None
+    prev_cursor: str | None = None
+    items_per_page: int
+    has_more: bool
+
+
+class PaginationType(str, Enum):
+    """Pagination strategy selector for :meth:`.AsyncCrud.paginate`."""
+
+    OFFSET = "offset"
+    CURSOR = "cursor"
+
+
+class PaginatedResponse(BaseResponse, Generic[DataT]):
+    """Paginated API response for list endpoints.
+
+    Base class and return type for endpoints that support both pagination
+    strategies.  Use :class:`OffsetPaginatedResponse` or
+    :class:`CursorPaginatedResponse` when the strategy is fixed.
+
+    When used as ``PaginatedResponse[T]`` in a return annotation, subscripting
+    returns ``Annotated[Union[CursorPaginatedResponse[T], OffsetPaginatedResponse[T]], Field(discriminator="pagination_type")]``
+    so FastAPI emits a proper ``oneOf`` + discriminator in the OpenAPI schema.
+    """
+
+    data: list[DataT]
+    pagination: OffsetPagination | CursorPagination
+    pagination_type: PaginationType | None = None
+    filter_attributes: dict[str, list[Any]] | None = None
+    search_columns: list[str] | None = None
+    order_columns: list[str] | None = None
+
+    _discriminated_union_cache: ClassVar[dict[Any, Any]] = {}
+
+    def __class_getitem__(  # ty:ignore[invalid-method-override]
+        cls, item: type[Any] | tuple[type[Any], ...]
+    ) -> type[Any]:
+        if cls is PaginatedResponse and not isinstance(item, TypeVar):
+            cached = cls._discriminated_union_cache.get(item)
+            if cached is None:
+                cached = Annotated[
+                    CursorPaginatedResponse[item] | OffsetPaginatedResponse[item],  # ty:ignore[invalid-type-form]
+                    Field(discriminator="pagination_type"),
+                ]
+                cls._discriminated_union_cache[item] = cached
+            return cached  # ty:ignore[invalid-return-type]
+        return super().__class_getitem__(item)  # ty:ignore[invalid-return-type]
+
+
+class OffsetPaginatedResponse(PaginatedResponse[DataT]):
+    """Paginated response with typed offset-based pagination metadata.
+
+    The ``pagination_type`` field is always ``"offset"`` and acts as a
+    discriminator, allowing frontend clients to narrow the union type returned
+    by a unified ``paginate()`` endpoint.
+    """
+
+    pagination: OffsetPagination
+    pagination_type: Literal[PaginationType.OFFSET] = PaginationType.OFFSET
+
+
+class CursorPaginatedResponse(PaginatedResponse[DataT]):
+    """Paginated response with typed cursor-based pagination metadata.
+
+    The ``pagination_type`` field is always ``"cursor"`` and acts as a
+    discriminator, allowing frontend clients to narrow the union type returned
+    by a unified ``paginate()`` endpoint.
+    """
+
+    pagination: CursorPagination
+    pagination_type: Literal[PaginationType.CURSOR] = PaginationType.CURSOR

src/fastapi_toolsets/types.py

@@ -0,0 +1,28 @@
+"""Shared type aliases for the fastapi-toolsets package."""
+
+from collections.abc import AsyncGenerator, Callable, Mapping
+from typing import Any, TypeVar
+
+from pydantic import BaseModel
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import DeclarativeBase, QueryableAttribute
+from sqlalchemy.orm.attributes import InstrumentedAttribute
+from sqlalchemy.sql.elements import ColumnElement
+
+# Generic TypeVars
+DataT = TypeVar("DataT")
+ModelType = TypeVar("ModelType", bound=DeclarativeBase)
+SchemaType = TypeVar("SchemaType", bound=BaseModel)
+
+# CRUD type aliases
+JoinType = list[tuple[type[DeclarativeBase] | Any, Any]]
+M2MFieldType = Mapping[str, QueryableAttribute[Any]]
+OrderByClause = ColumnElement[Any] | QueryableAttribute[Any]
+
+# Search / facet / order type aliases
+SearchFieldType = InstrumentedAttribute[Any] | tuple[InstrumentedAttribute[Any], ...]
+FacetFieldType = SearchFieldType
+OrderFieldType = SearchFieldType
+
+# Dependency type aliases
+SessionDependency = Callable[[], AsyncGenerator[AsyncSession, None]] | Any

stable

@@ -1 +0,0 @@
-v5.1

tests/__init__.py

@@ -0,0 +1 @@
+"""Tests for fastapi-utils package."""

tests/conftest.py

@@ -0,0 +1,500 @@
+"""Shared pytest fixtures for fastapi-utils tests."""
+
+import datetime
+import decimal
+import os
+import uuid
+from enum import Enum
+
+import pytest
+from pydantic import BaseModel
+from sqlalchemy import (
+    JSON,
+    Column,
+    Date,
+    DateTime,
+    ForeignKey,
+    Integer,
+    Numeric,
+    String,
+    Table,
+    Uuid,
+)
+from sqlalchemy import (
+    Enum as SAEnum,
+)
+from sqlalchemy.dialects.postgresql import ARRAY
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship
+
+from fastapi_toolsets.crud import CrudFactory
+from fastapi_toolsets.schemas import PydanticBase
+
+DATABASE_URL = os.getenv(
+    key="DATABASE_URL",
+    default="postgresql+asyncpg://postgres:postgres@localhost:5432/postgres",
+)
+
+
+class Base(DeclarativeBase):
+    """Base class for test models."""
+
+
+class Role(Base):
+    """Test role model."""
+
+    __tablename__ = "roles"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(50), unique=True)
+
+    users: Mapped[list["User"]] = relationship(back_populates="role")
+
+
+class User(Base):
+    """Test user model."""
+
+    __tablename__ = "users"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    username: Mapped[str] = mapped_column(String(50), unique=True)
+    email: Mapped[str] = mapped_column(String(100), unique=True)
+    is_active: Mapped[bool] = mapped_column(default=True)
+    notes: Mapped[str | None]
+    role_id: Mapped[uuid.UUID | None] = mapped_column(
+        ForeignKey("roles.id"), nullable=True
+    )
+
+    role: Mapped[Role | None] = relationship(back_populates="users")
+
+
+class Tag(Base):
+    """Test tag model."""
+
+    __tablename__ = "tags"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(50), unique=True)
+
+
+post_tags = Table(
+    "post_tags",
+    Base.metadata,
+    Column(
+        "post_id", Uuid, ForeignKey("posts.id", ondelete="CASCADE"), primary_key=True
+    ),
+    Column("tag_id", Uuid, ForeignKey("tags.id", ondelete="CASCADE"), primary_key=True),
+)
+
+
+class IntRole(Base):
+    """Test role model with auto-increment integer PK."""
+
+    __tablename__ = "int_roles"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
+    name: Mapped[str] = mapped_column(String(50), unique=True)
+
+
+class Permission(Base):
+    """Test model with composite primary key."""
+
+    __tablename__ = "permissions"
+
+    subject: Mapped[str] = mapped_column(String(50), primary_key=True)
+    action: Mapped[str] = mapped_column(String(50), primary_key=True)
+
+
+class Event(Base):
+    """Test model with DateTime and Date cursor columns."""
+
+    __tablename__ = "events"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(100))
+    occurred_at: Mapped[datetime.datetime] = mapped_column(DateTime)
+    scheduled_date: Mapped[datetime.date] = mapped_column(Date)
+
+
+class Product(Base):
+    """Test model with Numeric cursor column."""
+
+    __tablename__ = "products"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(100))
+    price: Mapped[decimal.Decimal] = mapped_column(Numeric(10, 2))
+
+
+class Post(Base):
+    """Test post model."""
+
+    __tablename__ = "posts"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    title: Mapped[str] = mapped_column(String(200))
+    content: Mapped[str] = mapped_column(String(1000), default="")
+    is_published: Mapped[bool] = mapped_column(default=False)
+    author_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"))
+
+    tags: Mapped[list[Tag]] = relationship(secondary=post_tags)
+
+
+class OrderStatus(int, Enum):
+    """Integer-backed enum for order status."""
+
+    PENDING = 1
+    PROCESSING = 2
+    SHIPPED = 3
+    CANCELLED = 4
+
+
+class Color(str, Enum):
+    """String-backed enum for color."""
+
+    RED = "red"
+    GREEN = "green"
+    BLUE = "blue"
+
+
+class Order(Base):
+    """Test model with an IntEnum column (Enum(int, Enum)) and a raw Integer column."""
+
+    __tablename__ = "orders"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    name: Mapped[str] = mapped_column(String(100))
+    status: Mapped[OrderStatus] = mapped_column(SAEnum(OrderStatus))
+    priority: Mapped[int] = mapped_column(Integer)
+    color: Mapped[Color] = mapped_column(SAEnum(Color))
+
+
+class Transfer(Base):
+    """Test model with two FKs to the same table (users)."""
+
+    __tablename__ = "transfers"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    amount: Mapped[str] = mapped_column(String(50))
+    sender_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"))
+    receiver_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("users.id"))
+
+
+class Article(Base):
+    """Test article model with ARRAY and JSON columns."""
+
+    __tablename__ = "articles"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    title: Mapped[str] = mapped_column(String(200))
+    labels: Mapped[list[str]] = mapped_column(ARRAY(String))
+    metadata_: Mapped[dict | None] = mapped_column("metadata", JSON, nullable=True)
+
+
+class Challenge(Base):
+    """Base challenge model (root of joined-table inheritance hierarchy)."""
+
+    __tablename__ = "challenges"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid, primary_key=True, default=uuid.uuid4)
+    title: Mapped[str] = mapped_column(String(200))
+    challenge_type: Mapped[str] = mapped_column(String(50))
+    points: Mapped[int] = mapped_column(Integer, default=0)
+
+    __mapper_args__ = {
+        "polymorphic_on": "challenge_type",
+        "polymorphic_identity": "challenge",
+    }
+
+
+class ChallengeStandard(Challenge):
+    """Standard challenge — child table in joined-table inheritance."""
+
+    __tablename__ = "challenge_standard"
+
+    id: Mapped[uuid.UUID] = mapped_column(ForeignKey("challenges.id"), primary_key=True)
+    difficulty: Mapped[str] = mapped_column(String(50))
+
+    __mapper_args__ = {
+        "polymorphic_identity": "standard",
+    }
+
+
+class RoleCreate(BaseModel):
+    """Schema for creating a role."""
+
+    id: uuid.UUID | None = None
+    name: str
+
+
+class RoleRead(PydanticBase):
+    """Schema for reading a role."""
+
+    id: uuid.UUID
+    name: str
+
+
+class RoleUpdate(BaseModel):
+    """Schema for updating a role."""
+
+    name: str | None = None
+
+
+class UserCreate(BaseModel):
+    """Schema for creating a user."""
+
+    id: uuid.UUID | None = None
+    username: str
+    email: str
+    is_active: bool = True
+    role_id: uuid.UUID | None = None
+
+
+class UserRead(PydanticBase):
+    """Schema for reading a user (subset of fields — no email)."""
+
+    id: uuid.UUID
+    username: str
+    is_active: bool = True
+
+
+class UserUpdate(BaseModel):
+    """Schema for updating a user."""
+
+    username: str | None = None
+    email: str | None = None
+    is_active: bool | None = None
+    role_id: uuid.UUID | None = None
+
+
+class TagCreate(BaseModel):
+    """Schema for creating a tag."""
+
+    id: uuid.UUID | None = None
+    name: str
+
+
+class PostCreate(BaseModel):
+    """Schema for creating a post."""
+
+    id: uuid.UUID | None = None
+    title: str
+    content: str = ""
+    is_published: bool = False
+    author_id: uuid.UUID
+
+
+class PostUpdate(BaseModel):
+    """Schema for updating a post."""
+
+    title: str | None = None
+    content: str | None = None
+    is_published: bool | None = None
+
+
+class PostM2MCreate(BaseModel):
+    """Schema for creating a post with M2M tag IDs."""
+
+    id: uuid.UUID | None = None
+    title: str
+    content: str = ""
+    is_published: bool = False
+    author_id: uuid.UUID
+    tag_ids: list[uuid.UUID] = []
+
+
+class PostM2MUpdate(BaseModel):
+    """Schema for updating a post with M2M tag IDs."""
+
+    title: str | None = None
+    content: str | None = None
+    is_published: bool | None = None
+    tag_ids: list[uuid.UUID] | None = None
+
+
+class IntRoleRead(PydanticBase):
+    """Schema for reading an IntRole."""
+
+    id: int
+    name: str
+
+
+class IntRoleCreate(BaseModel):
+    """Schema for creating an IntRole."""
+
+    name: str
+
+
+class EventRead(PydanticBase):
+    """Schema for reading an Event."""
+
+    id: uuid.UUID
+    name: str
+
+
+class EventCreate(BaseModel):
+    """Schema for creating an Event."""
+
+    name: str
+    occurred_at: datetime.datetime
+    scheduled_date: datetime.date
+
+
+class ProductRead(PydanticBase):
+    """Schema for reading a Product."""
+
+    id: uuid.UUID
+    name: str
+
+
+class ProductCreate(BaseModel):
+    """Schema for creating a Product."""
+
+    name: str
+    price: decimal.Decimal
+
+
+class ArticleCreate(BaseModel):
+    """Schema for creating an article."""
+
+    id: uuid.UUID | None = None
+    title: str
+    labels: list[str] = []
+
+
+class ArticleRead(PydanticBase):
+    """Schema for reading an article."""
+
+    id: uuid.UUID
+    title: str
+    labels: list[str]
+
+
+class OrderCreate(BaseModel):
+    """Schema for creating an order."""
+
+    id: uuid.UUID | None = None
+    name: str
+    status: OrderStatus
+    priority: int = 0
+    color: Color = Color.RED
+
+
+class OrderRead(PydanticBase):
+    """Schema for reading an order."""
+
+    id: uuid.UUID
+    name: str
+    status: OrderStatus
+    priority: int
+    color: Color
+
+
+class TransferCreate(BaseModel):
+    """Schema for creating a transfer."""
+
+    id: uuid.UUID | None = None
+    amount: str
+    sender_id: uuid.UUID
+    receiver_id: uuid.UUID
+
+
+class TransferRead(PydanticBase):
+    """Schema for reading a transfer."""
+
+    id: uuid.UUID
+    amount: str
+
+
+OrderCrud = CrudFactory(Order)
+TransferCrud = CrudFactory(Transfer)
+ArticleCrud = CrudFactory(Article)
+RoleCrud = CrudFactory(Role)
+RoleCursorCrud = CrudFactory(Role, cursor_column=Role.id)
+IntRoleCursorCrud = CrudFactory(IntRole, cursor_column=IntRole.id)
+UserCrud = CrudFactory(User)
+UserCursorCrud = CrudFactory(User, cursor_column=User.id)
+PostCrud = CrudFactory(Post)
+TagCrud = CrudFactory(Tag)
+PostM2MCrud = CrudFactory(Post, m2m_fields={"tag_ids": Post.tags})
+EventCrud = CrudFactory(Event)
+EventDateTimeCursorCrud = CrudFactory(Event, cursor_column=Event.occurred_at)
+EventDateCursorCrud = CrudFactory(Event, cursor_column=Event.scheduled_date)
+ProductCrud = CrudFactory(Product)
+ProductNumericCursorCrud = CrudFactory(Product, cursor_column=Product.price)
+
+
+@pytest.fixture
+def anyio_backend():
+    """Use asyncio for async tests."""
+    return "asyncio"
+
+
+@pytest.fixture(scope="function")
+async def engine():
+    """Create a PostgreSQL test database engine."""
+    engine = create_async_engine(DATABASE_URL, echo=False)
+    yield engine
+    await engine.dispose()
+
+
+@pytest.fixture(scope="function")
+async def session_maker(engine):
+    """Provide a session factory with tables created and dropped around the test."""
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+
+    factory = async_sessionmaker(engine, expire_on_commit=False)
+
+    try:
+        yield factory
+    finally:
+        async with engine.begin() as conn:
+            await conn.run_sync(Base.metadata.drop_all)
+
+
+@pytest.fixture(scope="function")
+async def db_session(engine):
+    """Create a test database session with tables.
+
+    Creates all tables before the test and drops them after.
+    Each test gets a clean database state.
+    """
+    # Create tables
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+
+    # Create session
+    session_factory = async_sessionmaker(engine, expire_on_commit=False)
+    session = session_factory()
+
+    try:
+        yield session
+    finally:
+        await session.close()
+        # Drop tables after test
+        async with engine.begin() as conn:
+            await conn.run_sync(Base.metadata.drop_all)
+
+
+@pytest.fixture(scope="function")
+async def db_session_expire_on_commit(engine):
+    """Session with expire_on_commit=True (the SQLAlchemy default).
+
+    Attributes read off an instance after commit are expired and trigger an
+    implicit (sync) refresh under this setting — which fails under asyncio
+    with MissingGreenlet. The other ``db_session`` fixture uses
+    ``expire_on_commit=False`` and would not catch that class of bug.
+    """
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+
+    session_factory = async_sessionmaker(engine, expire_on_commit=True)
+    session = session_factory()
+
+    try:
+        yield session
+    finally:
+        await session.close()
+        async with engine.begin() as conn:
+            await conn.run_sync(Base.metadata.drop_all)

tests/test_cli.py

@@ -0,0 +1,567 @@
+"""Tests for fastapi_toolsets.cli module."""
+
+import sys
+
+import pytest
+from typer.testing import CliRunner
+
+from fastapi_toolsets.cli.config import (
+    get_config_value,
+    get_custom_cli,
+    get_db_context,
+    get_fixtures_registry,
+    import_from_string,
+)
+from fastapi_toolsets.cli.pyproject import find_pyproject, load_pyproject
+from fastapi_toolsets.cli.utils import async_command
+from fastapi_toolsets.fixtures import FixtureRegistry
+
+runner = CliRunner()
+
+
+class TestPyproject:
+    """Tests for pyproject.toml discovery and loading."""
+
+    def test_find_pyproject_in_current_dir(self, tmp_path, monkeypatch):
+        """Finds pyproject.toml in current directory."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[project]\nname = 'test'\n")
+        monkeypatch.chdir(tmp_path)
+
+        result = find_pyproject()
+        assert result == pyproject
+
+    def test_find_pyproject_in_parent_dir(self, tmp_path, monkeypatch):
+        """Finds pyproject.toml in parent directory."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[project]\nname = 'test'\n")
+        subdir = tmp_path / "src" / "app"
+        subdir.mkdir(parents=True)
+        monkeypatch.chdir(subdir)
+
+        result = find_pyproject()
+        assert result == pyproject
+
+    def test_find_pyproject_not_found(self, tmp_path, monkeypatch):
+        """Returns None when no pyproject.toml exists."""
+        monkeypatch.chdir(tmp_path)
+        result = find_pyproject()
+        assert result is None
+
+    def test_load_pyproject_returns_tool_config(self, tmp_path, monkeypatch):
+        """load_pyproject returns the [tool.fastapi-toolsets] section."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text(
+            '[tool.fastapi-toolsets]\nfixtures = "app.fixtures:registry"\n'
+        )
+        monkeypatch.chdir(tmp_path)
+
+        result = load_pyproject()
+        assert result == {"fixtures": "app.fixtures:registry"}
+
+    def test_load_pyproject_empty_when_no_file(self, tmp_path, monkeypatch):
+        """Returns empty dict when no pyproject.toml exists."""
+        monkeypatch.chdir(tmp_path)
+        result = load_pyproject()
+        assert result == {}
+
+    def test_load_pyproject_empty_when_no_tool_section(self, tmp_path, monkeypatch):
+        """Returns empty dict when no [tool.fastapi-toolsets] section."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[project]\nname = 'test'\n")
+        monkeypatch.chdir(tmp_path)
+
+        result = load_pyproject()
+        assert result == {}
+
+    def test_load_pyproject_invalid_toml(self, tmp_path, monkeypatch):
+        """Returns empty dict when pyproject.toml is invalid."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("invalid toml {{{")
+        monkeypatch.chdir(tmp_path)
+
+        result = load_pyproject()
+        assert result == {}
+
+
+class TestImportFromString:
+    """Tests for import_from_string function."""
+
+    def test_import_valid_path(self):
+        """Import valid module:attribute path."""
+        result = import_from_string("fastapi_toolsets.fixtures:FixtureRegistry")
+        assert result is FixtureRegistry
+
+    def test_import_without_colon_raises_error(self):
+        """Import path without colon raises error."""
+        with pytest.raises(Exception) as exc_info:
+            import_from_string("fastapi_toolsets.fixtures.FixtureRegistry")
+        assert "Expected format: 'module:attribute'" in str(exc_info.value)
+
+    def test_import_nonexistent_module_raises_error(self):
+        """Import nonexistent module raises error."""
+        with pytest.raises(Exception) as exc_info:
+            import_from_string("nonexistent.module:something")
+        assert "Cannot import module" in str(exc_info.value)
+
+    def test_import_nonexistent_attribute_raises_error(self):
+        """Import nonexistent attribute raises error."""
+        with pytest.raises(Exception) as exc_info:
+            import_from_string("fastapi_toolsets.fixtures:NonexistentClass")
+        assert "has no attribute" in str(exc_info.value)
+
+
+class TestGetConfigValue:
+    """Tests for get_config_value function."""
+
+    def test_get_existing_value(self, tmp_path, monkeypatch):
+        """Returns value when key exists."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text('[tool.fastapi-toolsets]\nfixtures = "app:registry"\n')
+        monkeypatch.chdir(tmp_path)
+
+        result = get_config_value("fixtures")
+        assert result == "app:registry"
+
+    def test_get_missing_value_returns_none(self, tmp_path, monkeypatch):
+        """Returns None when key is missing and not required."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[tool.fastapi-toolsets]\n")
+        monkeypatch.chdir(tmp_path)
+
+        result = get_config_value("fixtures")
+        assert result is None
+
+    def test_get_missing_value_required_raises_error(self, tmp_path, monkeypatch):
+        """Raises error when key is missing and required."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[tool.fastapi-toolsets]\n")
+        monkeypatch.chdir(tmp_path)
+
+        with pytest.raises(Exception) as exc_info:
+            get_config_value("fixtures", required=True)
+        assert "No 'fixtures' configured" in str(exc_info.value)
+
+
+class TestGetFixturesRegistry:
+    """Tests for get_fixtures_registry function."""
+
+    def test_raises_when_not_configured(self, tmp_path, monkeypatch):
+        """Raises error when fixtures not configured."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[tool.fastapi-toolsets]\n")
+        monkeypatch.chdir(tmp_path)
+
+        with pytest.raises(Exception) as exc_info:
+            get_fixtures_registry()
+        assert "No 'fixtures' configured" in str(exc_info.value)
+
+    def test_raises_when_not_registry_instance(self, tmp_path, monkeypatch):
+        """Raises error when imported object is not a FixtureRegistry."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text(
+            '[tool.fastapi-toolsets]\nfixtures = "my_fixtures:registry"\n'
+        )
+
+        fixtures_file = tmp_path / "my_fixtures.py"
+        fixtures_file.write_text("registry = 'not a registry'\n")
+
+        monkeypatch.chdir(tmp_path)
+        if str(tmp_path) not in sys.path:
+            sys.path.insert(0, str(tmp_path))
+
+        try:
+            with pytest.raises(Exception) as exc_info:
+                get_fixtures_registry()
+            assert "must be a FixtureRegistry instance" in str(exc_info.value)
+        finally:
+            if str(tmp_path) in sys.path:
+                sys.path.remove(str(tmp_path))
+            if "my_fixtures" in sys.modules:
+                del sys.modules["my_fixtures"]
+
+
+class TestGetDbContext:
+    """Tests for get_db_context function."""
+
+    def test_raises_when_not_configured(self, tmp_path, monkeypatch):
+        """Raises error when db_context not configured."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[tool.fastapi-toolsets]\n")
+        monkeypatch.chdir(tmp_path)
+
+        with pytest.raises(Exception) as exc_info:
+            get_db_context()
+        assert "No 'db_context' configured" in str(exc_info.value)
+
+
+class TestGetCustomCli:
+    """Tests for get_custom_cli function."""
+
+    def test_returns_none_when_not_configured(self, tmp_path, monkeypatch):
+        """Returns None when custom_cli not configured."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text("[tool.fastapi-toolsets]\n")
+        monkeypatch.chdir(tmp_path)
+
+        result = get_custom_cli()
+        assert result is None
+
+    def test_raises_when_not_typer_instance(self, tmp_path, monkeypatch):
+        """Raises error when imported object is not a Typer instance."""
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text('[tool.fastapi-toolsets]\ncustom_cli = "my_cli:cli"\n')
+
+        cli_file = tmp_path / "my_cli.py"
+        cli_file.write_text("cli = 'not a typer'\n")
+
+        monkeypatch.chdir(tmp_path)
+        if str(tmp_path) not in sys.path:
+            sys.path.insert(0, str(tmp_path))
+
+        try:
+            with pytest.raises(Exception) as exc_info:
+                get_custom_cli()
+            assert "must be a Typer instance" in str(exc_info.value)
+        finally:
+            if str(tmp_path) in sys.path:
+                sys.path.remove(str(tmp_path))
+            if "my_cli" in sys.modules:
+                del sys.modules["my_cli"]
+
+
+class TestCliApp:
+    """Tests for CLI application."""
+
+    def test_cli_help(self, tmp_path, monkeypatch):
+        """CLI shows help without fixtures."""
+        monkeypatch.chdir(tmp_path)
+
+        # Need to reload the module to pick up new cwd
+        import importlib
+
+        from fastapi_toolsets.cli import app
+
+        importlib.reload(app)
+
+        result = runner.invoke(app.cli, ["--help"])
+        assert result.exit_code == 0
+        assert "CLI utilities for FastAPI projects" in result.output
+
+
+class TestFixturesCli:
+    """Tests for fixtures CLI commands."""
+
+    @pytest.fixture
+    def cli_env(self, tmp_path, monkeypatch):
+        """Set up CLI environment with fixtures config."""
+        # Create pyproject.toml
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text(
+            "[tool.fastapi-toolsets]\n"
+            'fixtures = "fixtures:registry"\n'
+            'db_context = "db:get_session"\n'
+        )
+
+        # Create fixtures module
+        fixtures_file = tmp_path / "fixtures.py"
+        fixtures_file.write_text(
+            "from fastapi_toolsets.fixtures import FixtureRegistry, Context\n"
+            "\n"
+            "registry = FixtureRegistry()\n"
+            "\n"
+            "@registry.register(contexts=[Context.BASE])\n"
+            "def roles():\n"
+            '    return [{"id": 1, "name": "admin"}, {"id": 2, "name": "user"}]\n'
+            "\n"
+            '@registry.register(depends_on=["roles"], contexts=[Context.TESTING])\n'
+            "def users():\n"
+            '    return [{"id": 1, "name": "alice", "role_id": 1}]\n'
+            "\n"
+            '@registry.register(contexts=["staging"])\n'
+            "def staging_only():\n"
+            '    return [{"id": 3, "name": "staging-user"}]\n'
+        )
+
+        # Create db module
+        db_file = tmp_path / "db.py"
+        db_file.write_text(
+            "from contextlib import asynccontextmanager\n"
+            "\n"
+            "@asynccontextmanager\n"
+            "async def get_session():\n"
+            "    yield None\n"
+        )
+
+        monkeypatch.chdir(tmp_path)
+
+        # Add tmp_path to sys.path for imports
+        if str(tmp_path) not in sys.path:
+            sys.path.insert(0, str(tmp_path))
+
+        # Reload the CLI module to pick up new config
+        import importlib
+
+        from fastapi_toolsets.cli import app
+
+        importlib.reload(app)
+
+        yield tmp_path, app.cli
+
+        # Cleanup
+        if str(tmp_path) in sys.path:
+            sys.path.remove(str(tmp_path))
+
+    def test_fixtures_list(self, cli_env):
+        """fixtures list shows registered fixtures."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(cli, ["fixtures", "list"])
+
+        assert result.exit_code == 0
+        assert "roles" in result.output
+        assert "users" in result.output
+        assert "Total: 3 fixture(s)" in result.output
+
+    def test_fixtures_list_with_context(self, cli_env):
+        """fixtures list --context filters by context."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(cli, ["fixtures", "list", "--context", "base"])
+
+        assert result.exit_code == 0
+        assert "roles" in result.output
+        assert "users" not in result.output
+        assert "Total: 1 fixture(s)" in result.output
+
+    def test_fixtures_load_dry_run(self, cli_env):
+        """fixtures load --dry-run shows what would be loaded."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(cli, ["fixtures", "load", "base", "--dry-run"])
+
+        assert result.exit_code == 0
+        assert "Fixtures to load" in result.output
+        assert "roles" in result.output
+        assert "[Dry run - no changes made]" in result.output
+
+    def test_fixtures_list_with_custom_context(self, cli_env):
+        """fixtures list --context accepts contexts outside the Context enum, and
+        always includes base fixtures alongside the requested context."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(cli, ["fixtures", "list", "--context", "staging"])
+
+        assert result.exit_code == 0
+        assert "staging_only" in result.output
+        assert "roles" in result.output
+        assert "Total: 2 fixture(s)" in result.output
+
+    def test_fixtures_load_custom_context_dry_run(self, cli_env):
+        """fixtures load accepts a custom context argument outside the Context enum,
+        and always loads base fixtures alongside it."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(cli, ["fixtures", "load", "staging", "--dry-run"])
+
+        assert result.exit_code == 0
+        assert "staging_only" in result.output
+        assert "roles" in result.output
+
+    def test_fixtures_load_invalid_strategy(self, cli_env):
+        """fixtures load with invalid strategy shows error."""
+        tmp_path, cli = cli_env
+        result = runner.invoke(
+            cli, ["fixtures", "load", "base", "--strategy", "invalid"]
+        )
+
+        assert result.exit_code != 0
+
+
+class TestCliWithoutFixturesConfig:
+    """Tests for CLI when fixtures is not configured."""
+
+    def test_no_fixtures_command(self, tmp_path, monkeypatch):
+        """fixtures command is not available when not configured."""
+        # Create pyproject.toml without fixtures
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text('[project]\nname = "test"\n')
+
+        monkeypatch.chdir(tmp_path)
+
+        # Reload the CLI module
+        import importlib
+
+        from fastapi_toolsets.cli import app
+
+        importlib.reload(app)
+
+        result = runner.invoke(app.cli, ["--help"])
+
+        assert result.exit_code == 0
+        assert "fixtures" not in result.output
+
+
+class TestCustomCliConfig:
+    """Tests for custom CLI configuration."""
+
+    def test_cli_with_custom_cli(self, tmp_path, monkeypatch):
+        """CLI uses custom Typer instance when configured."""
+        import typer
+
+        # Create pyproject.toml with custom_cli config
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text('[tool.fastapi-toolsets]\ncustom_cli = "my_cli:cli"\n')
+
+        # Create custom CLI module with its own Typer and commands
+        cli_file = tmp_path / "my_cli.py"
+        cli_file.write_text(
+            "import typer\n"
+            "\n"
+            "cli = typer.Typer(name='my-app', help='My custom CLI')\n"
+            "\n"
+            "@cli.command()\n"
+            "def hello():\n"
+            '    print("Hello from custom CLI!")\n'
+        )
+
+        monkeypatch.chdir(tmp_path)
+
+        # Add tmp_path to sys.path for imports
+        if str(tmp_path) not in sys.path:
+            sys.path.insert(0, str(tmp_path))
+
+        # Remove my_cli from sys.modules if it was previously loaded
+        if "my_cli" in sys.modules:
+            del sys.modules["my_cli"]
+
+        # Reload the CLI module to pick up new config
+        import importlib
+
+        from fastapi_toolsets.cli import app
+
+        importlib.reload(app)
+
+        try:
+            # Verify custom CLI is used
+            assert isinstance(app.cli, typer.Typer)
+
+            result = runner.invoke(app.cli, ["--help"])
+            assert result.exit_code == 0
+            assert "My custom CLI" in result.output
+            assert "hello" in result.output
+
+            result = runner.invoke(app.cli, ["hello"])
+            assert result.exit_code == 0
+            assert "Hello from custom CLI!" in result.output
+        finally:
+            if str(tmp_path) in sys.path:
+                sys.path.remove(str(tmp_path))
+            if "my_cli" in sys.modules:
+                del sys.modules["my_cli"]
+
+    def test_custom_cli_with_fixtures(self, tmp_path, monkeypatch):
+        """Custom CLI gets fixtures command added when configured."""
+        # Create pyproject.toml with both custom_cli and fixtures
+        pyproject = tmp_path / "pyproject.toml"
+        pyproject.write_text(
+            "[tool.fastapi-toolsets]\n"
+            'custom_cli = "my_cli:cli"\n'
+            'fixtures = "fixtures:registry"\n'
+            'db_context = "db:get_session"\n'
+        )
+
+        # Create custom CLI module
+        cli_file = tmp_path / "my_cli.py"
+        cli_file.write_text(
+            "import typer\n"
+            "\n"
+            "cli = typer.Typer(name='my-app', help='My custom CLI')\n"
+            "\n"
+            "@cli.command()\n"
+            "def hello():\n"
+            '    print("Hello!")\n'
+        )
+
+        # Create fixtures module
+        fixtures_file = tmp_path / "fixtures.py"
+        fixtures_file.write_text(
+            "from fastapi_toolsets.fixtures import FixtureRegistry\n"
+            "\n"
+            "registry = FixtureRegistry()\n"
+        )
+
+        # Create db module
+        db_file = tmp_path / "db.py"
+        db_file.write_text(
+            "from contextlib import asynccontextmanager\n"
+            "\n"
+            "@asynccontextmanager\n"
+            "async def get_session():\n"
+            "    yield None\n"
+        )
+
+        monkeypatch.chdir(tmp_path)
+
+        if str(tmp_path) not in sys.path:
+            sys.path.insert(0, str(tmp_path))
+
+        for mod in ["my_cli", "fixtures", "db"]:
+            if mod in sys.modules:
+                del sys.modules[mod]
+
+        import importlib
+
+        from fastapi_toolsets.cli import app
+
+        importlib.reload(app)
+
+        try:
+            result = runner.invoke(app.cli, ["--help"])
+            assert result.exit_code == 0
+            # Should have both custom command and fixtures
+            assert "hello" in result.output
+            assert "fixtures" in result.output
+        finally:
+            if str(tmp_path) in sys.path:
+                sys.path.remove(str(tmp_path))
+            for mod in ["my_cli", "fixtures", "db"]:
+                if mod in sys.modules:
+                    del sys.modules[mod]
+
+
+class TestAsyncCommand:
+    """Tests for async_command decorator."""
+
+    def test_async_command_runs_coroutine(self):
+        """async_command runs async function synchronously."""
+
+        @async_command
+        async def async_func(value: int) -> int:
+            return value * 2
+
+        result = async_func(21)
+        assert result == 42
+
+    def test_async_command_preserves_signature(self):
+        """async_command preserves function signature."""
+
+        @async_command
+        async def async_func(name: str, count: int = 1) -> str:
+            return f"{name} x {count}"
+
+        result = async_func("test", count=3)
+        assert result == "test x 3"
+
+    def test_async_command_preserves_docstring(self):
+        """async_command preserves function docstring."""
+
+        @async_command
+        async def async_func() -> None:
+            """This is a docstring."""
+
+        assert async_func.__doc__ == """This is a docstring."""
+
+    def test_async_command_preserves_name(self):
+        """async_command preserves function name."""
+
+        @async_command
+        async def my_async_function() -> None:
+            pass
+
+        assert my_async_function.__name__ == "my_async_function"

tests/test_dependencies.py

@@ -0,0 +1,277 @@
+"""Tests for fastapi_toolsets.dependencies module."""
+
+import inspect
+import uuid
+from collections.abc import AsyncGenerator
+from typing import Annotated, Any, cast
+
+import pytest
+from fastapi.params import Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from fastapi_toolsets.dependencies import (
+    BodyDependency,
+    PathDependency,
+    _unwrap_session_dep,
+)
+
+from .conftest import Role, RoleCreate, RoleCrud, User
+
+
+async def mock_get_db() -> AsyncGenerator[AsyncSession, None]:
+    """Mock session dependency for testing."""
+    yield None  # type: ignore[misc]  # ty:ignore[invalid-yield]
+
+
+MockSessionDep = Annotated[AsyncSession, Depends(mock_get_db)]
+
+
+class TestUnwrapSessionDep:
+    def test_plain_callable_returned_as_is(self):
+        """Plain callable is returned unchanged."""
+        assert _unwrap_session_dep(mock_get_db) is mock_get_db
+
+    def test_annotated_with_depends_unwrapped(self):
+        """Annotated form with Depends is unwrapped to the plain callable."""
+        assert _unwrap_session_dep(MockSessionDep) is mock_get_db
+
+    def test_annotated_without_depends_returned_as_is(self):
+        """Annotated form with no Depends falls back to returning session_dep as-is."""
+        annotated_no_dep = Annotated[AsyncSession, "not_a_depends"]
+        assert _unwrap_session_dep(annotated_no_dep) is annotated_no_dep
+
+
+class TestPathDependency:
+    """Tests for PathDependency factory."""
+
+    def test_returns_depends_instance(self):
+        """PathDependency returns a Depends instance."""
+        dep = PathDependency(Role, Role.id, session_dep=mock_get_db)
+        assert isinstance(dep, Depends)
+
+    def test_signature_has_default_param_name(self):
+        """PathDependency uses model_field as default param name."""
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=mock_get_db))
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+        params = list(sig.parameters.keys())
+
+        assert "role_id" in params
+        assert "session" in params
+
+    def test_signature_has_correct_type_annotation(self):
+        """PathDependency uses field's python type for annotation."""
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=mock_get_db))
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+
+        assert sig.parameters["role_id"].annotation == uuid.UUID
+        assert sig.parameters["session"].annotation == AsyncSession
+
+    def test_signature_session_has_depends_default(self):
+        """PathDependency session param has Depends as default."""
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=mock_get_db))
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+
+        assert isinstance(sig.parameters["session"].default, Depends)
+
+    def test_custom_param_name_in_signature(self):
+        """PathDependency uses custom param_name in signature."""
+        dep = cast(
+            Any,
+            PathDependency(
+                Role, Role.id, session_dep=mock_get_db, param_name="role_uuid"
+            ),
+        )
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+        params = list(sig.parameters.keys())
+
+        assert "role_uuid" in params
+        assert "id" not in params
+
+    def test_string_field_type(self):
+        """PathDependency handles string field types."""
+        dep = cast(Any, PathDependency(User, User.username, session_dep=mock_get_db))
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+
+        assert sig.parameters["user_username"].annotation is str
+
+    @pytest.mark.anyio
+    async def test_dependency_fetches_object(self, db_session):
+        """PathDependency inner function fetches object from database."""
+        role = await RoleCrud.create(db_session, RoleCreate(name="test_role"))
+
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=mock_get_db))
+        func = dep.dependency
+
+        result = await func(session=db_session, role_id=role.id)
+
+        assert result.id == role.id
+        assert result.name == "test_role"
+
+    def test_annotated_session_dep_returns_depends_instance(self):
+        """PathDependency accepts Annotated[AsyncSession, Depends(...)] form."""
+        dep = PathDependency(Role, Role.id, session_dep=MockSessionDep)
+        assert isinstance(dep, Depends)
+
+    def test_annotated_session_dep_signature(self):
+        """PathDependency with Annotated session_dep produces a valid signature."""
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=MockSessionDep))
+        sig = inspect.signature(dep.dependency)
+
+        assert "role_id" in sig.parameters
+        assert "session" in sig.parameters
+        assert isinstance(sig.parameters["session"].default, Depends)
+
+    def test_annotated_session_dep_unwraps_callable(self):
+        """PathDependency with Annotated form uses the underlying callable, not the Annotated type."""
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=MockSessionDep))
+        sig = inspect.signature(dep.dependency)
+
+        inner_dep = sig.parameters["session"].default
+        assert inner_dep.dependency is mock_get_db
+
+    @pytest.mark.anyio
+    async def test_annotated_session_dep_fetches_object(self, db_session):
+        """PathDependency with Annotated session_dep correctly fetches object from database."""
+        role = await RoleCrud.create(db_session, RoleCreate(name="annotated_role"))
+
+        dep = cast(Any, PathDependency(Role, Role.id, session_dep=MockSessionDep))
+        result = await dep.dependency(session=db_session, role_id=role.id)
+
+        assert result.id == role.id
+        assert result.name == "annotated_role"
+
+
+class TestBodyDependency:
+    """Tests for BodyDependency factory."""
+
+    def test_returns_depends_instance(self):
+        """BodyDependency returns a Depends instance."""
+        dep = BodyDependency(
+            Role, Role.id, session_dep=mock_get_db, body_field="role_id"
+        )
+        assert isinstance(dep, Depends)
+
+    def test_signature_has_body_field_as_param(self):
+        """BodyDependency uses body_field as param name."""
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=mock_get_db, body_field="role_id"
+            ),
+        )
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+        params = list(sig.parameters.keys())
+
+        assert "role_id" in params
+        assert "session" in params
+
+    def test_signature_has_correct_type_annotation(self):
+        """BodyDependency uses field's python type for annotation."""
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=mock_get_db, body_field="role_id"
+            ),
+        )
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+
+        assert sig.parameters["role_id"].annotation == uuid.UUID
+        assert sig.parameters["session"].annotation == AsyncSession
+
+    def test_signature_session_has_depends_default(self):
+        """BodyDependency session param has Depends as default."""
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=mock_get_db, body_field="role_id"
+            ),
+        )
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+
+        assert isinstance(sig.parameters["session"].default, Depends)
+
+    def test_different_body_field_name(self):
+        """BodyDependency can use any body_field name."""
+        dep = cast(
+            Any,
+            BodyDependency(
+                User, User.id, session_dep=mock_get_db, body_field="user_uuid"
+            ),
+        )
+        func = dep.dependency
+
+        sig = inspect.signature(func)
+        params = list(sig.parameters.keys())
+
+        assert "user_uuid" in params
+        assert "id" not in params
+
+    @pytest.mark.anyio
+    async def test_dependency_fetches_object(self, db_session):
+        """BodyDependency inner function fetches object from database."""
+        role = await RoleCrud.create(db_session, RoleCreate(name="body_test_role"))
+
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=mock_get_db, body_field="role_id"
+            ),
+        )
+        func = dep.dependency
+
+        result = await func(session=db_session, role_id=role.id)
+
+        assert result.id == role.id
+        assert result.name == "body_test_role"
+
+    def test_annotated_session_dep_returns_depends_instance(self):
+        """BodyDependency accepts Annotated[AsyncSession, Depends(...)] form."""
+        dep = BodyDependency(
+            Role, Role.id, session_dep=MockSessionDep, body_field="role_id"
+        )
+        assert isinstance(dep, Depends)
+
+    def test_annotated_session_dep_unwraps_callable(self):
+        """BodyDependency with Annotated form uses the underlying callable, not the Annotated type."""
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=MockSessionDep, body_field="role_id"
+            ),
+        )
+        sig = inspect.signature(dep.dependency)
+
+        inner_dep = sig.parameters["session"].default
+        assert inner_dep.dependency is mock_get_db
+
+    @pytest.mark.anyio
+    async def test_annotated_session_dep_fetches_object(self, db_session):
+        """BodyDependency with Annotated session_dep correctly fetches object from database."""
+        role = await RoleCrud.create(db_session, RoleCreate(name="body_annotated_role"))
+
+        dep = cast(
+            Any,
+            BodyDependency(
+                Role, Role.id, session_dep=MockSessionDep, body_field="role_id"
+            ),
+        )
+        result = await dep.dependency(session=db_session, role_id=role.id)
+
+        assert result.id == role.id
+        assert result.name == "body_annotated_role"

tests/test_example_pagination_search.py

@@ -0,0 +1,492 @@
+"""Live test for the docs/examples/pagination-search.md example.
+
+Spins up the exact FastAPI app described in the example (sourced from
+docs_src/examples/pagination_search/) and exercises it through a real HTTP
+client against a real PostgreSQL database.
+"""
+
+import datetime
+
+import pytest
+from fastapi import FastAPI
+from httpx import ASGITransport, AsyncClient
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from docs_src.examples.pagination_search.db import get_db
+from docs_src.examples.pagination_search.models import Article, Base, Category
+from docs_src.examples.pagination_search.routes import router
+from fastapi_toolsets.exceptions import init_exceptions_handlers
+from fastapi_toolsets.pytest import create_db_session
+
+from .conftest import DATABASE_URL
+
+
+def build_app(session: AsyncSession) -> FastAPI:
+    app = FastAPI()
+    init_exceptions_handlers(app)
+
+    async def override_get_db():
+        yield session
+
+    app.dependency_overrides[get_db] = override_get_db
+    app.include_router(router)
+    return app
+
+
+@pytest.fixture(scope="function")
+async def ex_db_session():
+    """Isolated session for the example models (separate tables from conftest)."""
+    async with create_db_session(DATABASE_URL, Base) as session:
+        yield session
+
+
+@pytest.fixture
+async def client(ex_db_session: AsyncSession):
+    app = build_app(ex_db_session)
+    async with AsyncClient(
+        transport=ASGITransport(app=app), base_url="http://test"
+    ) as ac:
+        yield ac
+
+
+async def seed(session: AsyncSession):
+    """Insert representative fixture data."""
+    python = Category(name="python")
+    backend = Category(name="backend")
+    session.add_all([python, backend])
+    await session.flush()
+
+    now = datetime.datetime(2024, 1, 1, tzinfo=datetime.UTC)
+    session.add_all(
+        [
+            Article(
+                title="FastAPI tips",
+                body="Ten useful tips for FastAPI.",
+                status="published",
+                published=True,
+                category_id=python.id,
+                created_at=now,
+            ),
+            Article(
+                title="SQLAlchemy async",
+                body="How to use async SQLAlchemy.",
+                status="published",
+                published=True,
+                category_id=backend.id,
+                created_at=now + datetime.timedelta(seconds=1),
+            ),
+            Article(
+                title="Draft notes",
+                body="Work in progress.",
+                status="draft",
+                published=False,
+                category_id=None,
+                created_at=now + datetime.timedelta(seconds=2),
+            ),
+        ]
+    )
+    await session.commit()
+
+
+class TestAppSessionDep:
+    @pytest.mark.anyio
+    async def test_get_db_yields_async_session(self):
+        """The Database dependency yields a real AsyncSession when called directly."""
+        from starlette.requests import Request
+
+        from fastapi_toolsets.db import Database
+
+        db = Database(DATABASE_URL)
+        try:
+            gen = db(Request({"type": "http", "headers": []}))
+            session = await gen.__anext__()
+            assert isinstance(session, AsyncSession)
+            await gen.aclose()
+        finally:
+            await db.engine.dispose()
+
+
+class TestOffsetPagination:
+    @pytest.mark.anyio
+    async def test_returns_all_articles(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 3
+        assert len(body["data"]) == 3
+
+    @pytest.mark.anyio
+    async def test_pagination_page_size(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?items_per_page=2&page=1")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body["data"]) == 2
+        assert body["pagination"]["total_count"] == 3
+        assert body["pagination"]["has_more"] is True
+
+    @pytest.mark.anyio
+    async def test_full_text_search(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?search=fastapi")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 1
+        assert body["data"][0]["title"] == "FastAPI tips"
+
+    @pytest.mark.anyio
+    async def test_search_traverses_relationship(
+        self, client: AsyncClient, ex_db_session
+    ):
+        await seed(ex_db_session)
+
+        # "python" matches Category.name, not Article.title or body
+        resp = await client.get("/articles/offset?search=python")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 1
+        assert body["data"][0]["title"] == "FastAPI tips"
+
+    @pytest.mark.anyio
+    async def test_facet_filter_scalar(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?status=published")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 2
+        assert all(a["status"] == "published" for a in body["data"])
+
+    @pytest.mark.anyio
+    async def test_facet_filter_multi_value(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?status=published&status=draft")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 3
+
+    @pytest.mark.anyio
+    async def test_filter_attributes_in_response(
+        self, client: AsyncClient, ex_db_session
+    ):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        fa = body["filter_attributes"]
+        assert set(fa["status"]) == {"draft", "published"}
+        assert set(fa["category__name"]) == {"backend", "python"}
+
+    @pytest.mark.anyio
+    async def test_filter_attributes_scoped_to_filter(
+        self, client: AsyncClient, ex_db_session
+    ):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?status=published")
+
+        body = resp.json()
+        # a facet excludes its own filter_by condition, so filtering by
+        # status=published still shows every status the facet offers
+        assert "draft" in body["filter_attributes"]["status"]
+
+    @pytest.mark.anyio
+    async def test_search_and_filter_combined(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?search=async&status=published")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination"]["total_count"] == 1
+        assert body["data"][0]["title"] == "SQLAlchemy async"
+
+
+class TestCursorPagination:
+    @pytest.mark.anyio
+    async def test_first_page(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor?items_per_page=2")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body["data"]) == 2
+        assert body["pagination"]["has_more"] is True
+        assert body["pagination"]["next_cursor"] is not None
+        assert body["pagination"]["prev_cursor"] is None
+
+    @pytest.mark.anyio
+    async def test_second_page(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        first = await client.get("/articles/cursor?items_per_page=2")
+        next_cursor = first.json()["pagination"]["next_cursor"]
+
+        resp = await client.get(
+            f"/articles/cursor?items_per_page=2&cursor={next_cursor}"
+        )
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body["data"]) == 1
+        assert body["pagination"]["has_more"] is False
+
+    @pytest.mark.anyio
+    async def test_facet_filter(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor?status=draft")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body["data"]) == 1
+        assert body["data"][0]["status"] == "draft"
+
+    @pytest.mark.anyio
+    async def test_full_text_search(self, client: AsyncClient, ex_db_session):
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor?search=sqlalchemy")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert len(body["data"]) == 1
+        assert body["data"][0]["title"] == "SQLAlchemy async"
+
+
+class TestOffsetSorting:
+    """Tests for order_by / order query parameters on the offset endpoint."""
+
+    @pytest.mark.anyio
+    async def test_default_order_uses_created_at_asc(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """No order_by → default field (created_at) ASC."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset")
+
+        assert resp.status_code == 200
+        titles = [a["title"] for a in resp.json()["data"]]
+        assert titles == ["FastAPI tips", "SQLAlchemy async", "Draft notes"]
+
+    @pytest.mark.anyio
+    async def test_order_by_title_asc(self, client: AsyncClient, ex_db_session):
+        """order_by=title&order=asc returns alphabetical order."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?order_by=title&order=asc")
+
+        assert resp.status_code == 200
+        titles = [a["title"] for a in resp.json()["data"]]
+        assert titles == ["Draft notes", "FastAPI tips", "SQLAlchemy async"]
+
+    @pytest.mark.anyio
+    async def test_order_by_title_desc(self, client: AsyncClient, ex_db_session):
+        """order_by=title&order=desc returns reverse alphabetical order."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?order_by=title&order=desc")
+
+        assert resp.status_code == 200
+        titles = [a["title"] for a in resp.json()["data"]]
+        assert titles == ["SQLAlchemy async", "FastAPI tips", "Draft notes"]
+
+    @pytest.mark.anyio
+    async def test_order_by_created_at_desc(self, client: AsyncClient, ex_db_session):
+        """order_by=created_at&order=desc returns newest-first."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/offset?order_by=created_at&order=desc")
+
+        assert resp.status_code == 200
+        titles = [a["title"] for a in resp.json()["data"]]
+        assert titles == ["Draft notes", "SQLAlchemy async", "FastAPI tips"]
+
+    @pytest.mark.anyio
+    async def test_invalid_order_by_returns_422(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """Unknown order_by field returns 422 with SORT-422 error code."""
+        resp = await client.get("/articles/offset?order_by=nonexistent_field")
+
+        assert resp.status_code == 422
+        body = resp.json()
+        assert body["error_code"] == "SORT-422"
+        assert body["status"] == "FAIL"
+
+
+class TestCursorSorting:
+    """Tests for order_by / order query parameters on the cursor endpoint.
+
+    In cursor_paginate the cursor_column is always the primary sort; order_by
+    acts as a secondary tiebreaker. With the seeded articles (all having unique
+    created_at values) the overall ordering is always created_at ASC regardless
+    of the order_by value — only the valid/invalid field check and the response
+    shape are meaningful here.
+    """
+
+    @pytest.mark.anyio
+    async def test_default_order_uses_created_at_asc(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """No order_by → default field (created_at) ASC."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor")
+
+        assert resp.status_code == 200
+        titles = [a["title"] for a in resp.json()["data"]]
+        assert titles == ["FastAPI tips", "SQLAlchemy async", "Draft notes"]
+
+    @pytest.mark.anyio
+    async def test_order_by_title_asc_accepted(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """order_by=title is a valid field — request succeeds and returns all articles."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor?order_by=title&order=asc")
+
+        assert resp.status_code == 200
+        assert len(resp.json()["data"]) == 3
+
+    @pytest.mark.anyio
+    async def test_order_by_title_desc_accepted(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """order_by=title&order=desc is valid — request succeeds and returns all articles."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/cursor?order_by=title&order=desc")
+
+        assert resp.status_code == 200
+        assert len(resp.json()["data"]) == 3
+
+    @pytest.mark.anyio
+    async def test_invalid_order_by_returns_422(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """Unknown order_by field returns 422 with SORT-422 error code."""
+        resp = await client.get("/articles/cursor?order_by=nonexistent_field")
+
+        assert resp.status_code == 422
+        body = resp.json()
+        assert body["error_code"] == "SORT-422"
+        assert body["status"] == "FAIL"
+
+
+class TestPaginateUnified:
+    """Tests for the unified GET /articles/ endpoint using paginate()."""
+
+    @pytest.mark.anyio
+    async def test_defaults_to_offset_pagination(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """Without pagination_type, defaults to offset pagination."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination_type"] == "offset"
+        assert "total_count" in body["pagination"]
+        assert body["pagination"]["total_count"] == 3
+
+    @pytest.mark.anyio
+    async def test_explicit_offset_pagination(self, client: AsyncClient, ex_db_session):
+        """pagination_type=offset returns OffsetPagination metadata."""
+        await seed(ex_db_session)
+
+        resp = await client.get(
+            "/articles/?pagination_type=offset&page=1&items_per_page=2"
+        )
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination_type"] == "offset"
+        assert body["pagination"]["total_count"] == 3
+        assert body["pagination"]["page"] == 1
+        assert body["pagination"]["has_more"] is True
+        assert len(body["data"]) == 2
+
+    @pytest.mark.anyio
+    async def test_cursor_pagination_type(self, client: AsyncClient, ex_db_session):
+        """pagination_type=cursor returns CursorPagination metadata."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/?pagination_type=cursor&items_per_page=2")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination_type"] == "cursor"
+        assert "next_cursor" in body["pagination"]
+        assert "total_count" not in body["pagination"]
+        assert body["pagination"]["has_more"] is True
+        assert len(body["data"]) == 2
+
+    @pytest.mark.anyio
+    async def test_cursor_pagination_navigate_pages(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """Cursor from first page can be used to fetch the next page."""
+        await seed(ex_db_session)
+
+        first = await client.get("/articles/?pagination_type=cursor&items_per_page=2")
+        assert first.status_code == 200
+        first_body = first.json()
+        next_cursor = first_body["pagination"]["next_cursor"]
+        assert next_cursor is not None
+
+        second = await client.get(
+            f"/articles/?pagination_type=cursor&items_per_page=2&cursor={next_cursor}"
+        )
+        assert second.status_code == 200
+        second_body = second.json()
+        assert second_body["pagination_type"] == "cursor"
+        assert second_body["pagination"]["has_more"] is False
+        assert len(second_body["data"]) == 1
+
+    @pytest.mark.anyio
+    async def test_cursor_pagination_with_search(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """paginate() with cursor type respects search parameter."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/?pagination_type=cursor&search=fastapi")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination_type"] == "cursor"
+        assert len(body["data"]) == 1
+        assert body["data"][0]["title"] == "FastAPI tips"
+
+    @pytest.mark.anyio
+    async def test_offset_pagination_with_filter(
+        self, client: AsyncClient, ex_db_session
+    ):
+        """paginate() with offset type respects filter_by parameter."""
+        await seed(ex_db_session)
+
+        resp = await client.get("/articles/?pagination_type=offset&status=published")
+
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["pagination_type"] == "offset"
+        assert body["pagination"]["total_count"] == 2

tests/test_exceptions.py

@@ -0,0 +1,834 @@
+"""Tests for fastapi_toolsets.exceptions module."""
+
+import pytest
+from fastapi import FastAPI
+from fastapi.exceptions import HTTPException
+from fastapi.testclient import TestClient
+
+from fastapi_toolsets.exceptions import (
+    ApiException,
+    ConflictError,
+    ForbiddenError,
+    InvalidOrderFieldError,
+    LockTimeoutError,
+    NotFoundError,
+    PoolExhaustedError,
+    UnauthorizedError,
+    generate_error_responses,
+    init_exceptions_handlers,
+)
+from fastapi_toolsets.schemas import ApiError
+
+
+class TestApiException:
+    """Tests for ApiException base class."""
+
+    def test_subclass_with_api_error(self):
+        """Subclasses can define api_error."""
+
+        class CustomError(ApiException):
+            api_error = ApiError(
+                code=418,
+                msg="I'm a teapot",
+                desc="The server is a teapot.",
+                err_code="TEA-418",
+            )
+
+        error = CustomError()
+        assert error.api_error.code == 418
+        assert error.api_error.msg == "I'm a teapot"
+        assert str(error) == "I'm a teapot"
+
+    def test_detail_overrides_msg_and_str(self):
+        """detail sets both str(exc) and api_error.msg; class-level msg is unchanged."""
+
+        class CustomError(ApiException):
+            api_error = ApiError(
+                code=400,
+                msg="Bad Request",
+                desc="Request was bad.",
+                err_code="BAD-400",
+            )
+
+        error = CustomError("Widget not found")
+        assert str(error) == "Widget not found"
+        assert error.api_error.msg == "Widget not found"
+        assert CustomError.api_error.msg == "Bad Request"  # class unchanged
+
+    def test_desc_override(self):
+        """desc kwarg overrides api_error.desc on the instance only."""
+
+        class MyError(ApiException):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Default.", err_code="ERR-400"
+            )
+
+        err = MyError(desc="Custom desc.")
+        assert err.api_error.desc == "Custom desc."
+        assert MyError.api_error.desc == "Default."  # class unchanged
+
+    def test_data_override(self):
+        """data kwarg sets api_error.data on the instance only."""
+
+        class MyError(ApiException):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Default.", err_code="ERR-400"
+            )
+
+        err = MyError(data={"key": "value"})
+        assert err.api_error.data == {"key": "value"}
+        assert MyError.api_error.data is None  # class unchanged
+
+    def test_desc_and_data_override(self):
+        """detail, desc and data can all be overridden together."""
+
+        class MyError(ApiException):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Default.", err_code="ERR-400"
+            )
+
+        err = MyError("custom msg", desc="New desc.", data={"x": 1})
+        assert str(err) == "custom msg"
+        assert err.api_error.msg == "custom msg"  # detail also updates msg
+        assert err.api_error.desc == "New desc."
+        assert err.api_error.data == {"x": 1}
+        assert err.api_error.code == 400  # other fields unchanged
+
+    def test_class_api_error_not_mutated_after_instance_override(self):
+        """Raising with desc/data does not mutate the class-level api_error."""
+
+        class MyError(ApiException):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Default.", err_code="ERR-400"
+            )
+
+        MyError(desc="Changed", data={"x": 1})
+        assert MyError.api_error.desc == "Default."
+        assert MyError.api_error.data is None
+
+    def test_subclass_uses_super_with_desc_and_data(self):
+        """Subclasses can delegate detail/desc/data to super().__init__()."""
+
+        class BuildValidationError(ApiException):
+            api_error = ApiError(
+                code=422,
+                msg="Build Validation Error",
+                desc="The build configuration is invalid.",
+                err_code="BUILD-422",
+            )
+
+            def __init__(self, *errors: str) -> None:
+                super().__init__(
+                    f"{len(errors)} validation error(s)",
+                    desc=", ".join(errors),
+                    data={"errors": [{"message": e} for e in errors]},
+                )
+
+        err = BuildValidationError("Field A is required", "Field B is invalid")
+        assert str(err) == "2 validation error(s)"
+        assert err.api_error.msg == "2 validation error(s)"  # detail set msg
+        assert err.api_error.desc == "Field A is required, Field B is invalid"
+        assert err.api_error.data == {
+            "errors": [
+                {"message": "Field A is required"},
+                {"message": "Field B is invalid"},
+            ]
+        }
+        assert err.api_error.code == 422  # other fields unchanged
+
+    def test_detail_desc_data_in_http_response(self):
+        """detail/desc/data overrides all appear correctly in the FastAPI HTTP response."""
+
+        class DynamicError(ApiException):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Default.", err_code="ERR-400"
+            )
+
+            def __init__(self, message: str) -> None:
+                super().__init__(
+                    message,
+                    desc=f"Detail: {message}",
+                    data={"reason": message},
+                )
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/error")
+        async def raise_error():
+            raise DynamicError("something went wrong")
+
+        client = TestClient(app)
+        response = client.get("/error")
+
+        assert response.status_code == 400
+        body = response.json()
+        assert body["message"] == "something went wrong"
+        assert body["description"] == "Detail: something went wrong"
+        assert body["data"] == {"reason": "something went wrong"}
+
+
+class TestApiExceptionGuard:
+    """Tests for the __init_subclass__ api_error guard."""
+
+    def test_missing_api_error_raises_type_error(self):
+        """Defining a subclass without api_error raises TypeError at class creation time."""
+        with pytest.raises(
+            TypeError, match="must define an 'api_error' class attribute"
+        ):
+
+            class BrokenError(ApiException):
+                pass
+
+    def test_abstract_subclass_skips_guard(self):
+        """abstract=True allows intermediate base classes without api_error."""
+
+        class BaseGroupError(ApiException, abstract=True):
+            pass
+
+        # Concrete child must still define it
+        class ConcreteError(BaseGroupError):
+            api_error = ApiError(
+                code=400, msg="Error", desc="Desc.", err_code="ERR-400"
+            )
+
+        err = ConcreteError()
+        assert err.api_error.code == 400
+
+    def test_abstract_child_still_requires_api_error_on_concrete(self):
+        """Concrete subclass of an abstract class must define api_error."""
+
+        class Base(ApiException, abstract=True):
+            pass
+
+        with pytest.raises(
+            TypeError, match="must define an 'api_error' class attribute"
+        ):
+
+            class Concrete(Base):
+                pass
+
+    def test_inherited_api_error_satisfies_guard(self):
+        """Subclass that inherits api_error from a parent does not need its own."""
+
+        class ConcreteError(NotFoundError):
+            pass
+
+        err = ConcreteError()
+        assert err.api_error.code == 404
+
+
+class TestDbExceptions:
+    """Tests for database-related exception classes."""
+
+    def test_pool_exhausted_error_attributes(self):
+        """PoolExhaustedError has 503 status and DB-503-POOL error code."""
+        error = PoolExhaustedError()
+        assert error.api_error.code == 503
+        assert error.api_error.err_code == "DB-503-POOL"
+        assert error.api_error.msg == "Service Unavailable"
+
+    def test_pool_exhausted_error_with_detail(self):
+        """PoolExhaustedError accepts a detail string that overrides msg."""
+        error = PoolExhaustedError("pool full")
+        assert error.api_error.msg == "pool full"
+        assert PoolExhaustedError.api_error.msg == "Service Unavailable"
+
+    def test_lock_timeout_error_attributes(self):
+        """LockTimeoutError has 503 status and DB-503-LOCK error code."""
+        error = LockTimeoutError()
+        assert error.api_error.code == 503
+        assert error.api_error.err_code == "DB-503-LOCK"
+        assert error.api_error.msg == "Service Unavailable"
+
+    def test_lock_timeout_error_with_detail(self):
+        """LockTimeoutError accepts a detail string that overrides msg."""
+        error = LockTimeoutError("contended")
+        assert error.api_error.msg == "contended"
+        assert LockTimeoutError.api_error.msg == "Service Unavailable"
+
+    def test_pool_exhausted_handled_as_503(self):
+        """init_exceptions_handlers turns PoolExhaustedError into a 503 response."""
+        from fastapi import FastAPI
+
+        from fastapi_toolsets.exceptions import init_exceptions_handlers
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/db")
+        async def endpoint():
+            raise PoolExhaustedError()
+
+        client = TestClient(app)
+        response = client.get("/db")
+        assert response.status_code == 503
+        assert response.json()["error_code"] == "DB-503-POOL"
+
+    def test_lock_timeout_handled_as_503(self):
+        """init_exceptions_handlers turns LockTimeoutError into a 503 response."""
+        from fastapi import FastAPI
+
+        from fastapi_toolsets.exceptions import init_exceptions_handlers
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/lock")
+        async def endpoint():
+            raise LockTimeoutError()
+
+        client = TestClient(app)
+        response = client.get("/lock")
+        assert response.status_code == 503
+        assert response.json()["error_code"] == "DB-503-LOCK"
+
+
+class TestBuiltInExceptions:
+    """Tests for built-in exception classes."""
+
+    def test_unauthorized_error(self):
+        """UnauthorizedError has correct attributes."""
+        error = UnauthorizedError()
+        assert error.api_error.code == 401
+        assert error.api_error.err_code == "AUTH-401"
+
+    def test_forbidden_error(self):
+        """ForbiddenError has correct attributes."""
+        error = ForbiddenError()
+        assert error.api_error.code == 403
+        assert error.api_error.err_code == "AUTH-403"
+
+    def test_not_found_error(self):
+        """NotFoundError has correct attributes."""
+        error = NotFoundError()
+        assert error.api_error.code == 404
+        assert error.api_error.err_code == "RES-404"
+
+    def test_conflict_error(self):
+        """ConflictError has correct attributes."""
+        error = ConflictError()
+        assert error.api_error.code == 409
+        assert error.api_error.err_code == "RES-409"
+
+
+class TestGenerateErrorResponses:
+    """Tests for generate_error_responses function."""
+
+    def test_generates_single_response(self):
+        """Generates response for single exception."""
+        responses = generate_error_responses(NotFoundError)
+
+        assert 404 in responses
+        assert responses[404]["description"] == "Not Found"
+
+    def test_generates_multiple_responses(self):
+        """Generates responses for multiple exceptions with distinct status codes."""
+        responses = generate_error_responses(
+            UnauthorizedError,
+            ForbiddenError,
+            NotFoundError,
+        )
+
+        assert 401 in responses
+        assert 403 in responses
+        assert 404 in responses
+
+    def test_response_has_named_example(self):
+        """Generated response uses named examples keyed by err_code."""
+        responses = generate_error_responses(NotFoundError)
+        examples = responses[404]["content"]["application/json"]["examples"]
+
+        assert "RES-404" in examples
+        value = examples["RES-404"]["value"]
+        assert value["status"] == "FAIL"
+        assert value["error_code"] == "RES-404"
+        assert value["message"] == "Not Found"
+        assert value["data"] is None
+
+    def test_response_example_has_summary(self):
+        """Each named example carries a summary equal to api_error.msg."""
+        responses = generate_error_responses(NotFoundError)
+        example = responses[404]["content"]["application/json"]["examples"]["RES-404"]
+
+        assert example["summary"] == "Not Found"
+
+    def test_response_example_with_data(self):
+        """Generated response includes data when set on ApiError."""
+
+        class ErrorWithData(ApiException):
+            api_error = ApiError(
+                code=400,
+                msg="Bad Request",
+                desc="Invalid input.",
+                err_code="BAD-400",
+                data={"details": "some context"},
+            )
+
+        responses = generate_error_responses(ErrorWithData)
+        value = responses[400]["content"]["application/json"]["examples"]["BAD-400"][
+            "value"
+        ]
+
+        assert value["data"] == {"details": "some context"}
+
+    def test_two_errors_same_code_both_present(self):
+        """Two exceptions with the same HTTP code produce two named examples."""
+
+        class BadRequestA(ApiException):
+            api_error = ApiError(
+                code=400, msg="Bad A", desc="Reason A.", err_code="ERR-A"
+            )
+
+        class BadRequestB(ApiException):
+            api_error = ApiError(
+                code=400, msg="Bad B", desc="Reason B.", err_code="ERR-B"
+            )
+
+        responses = generate_error_responses(BadRequestA, BadRequestB)
+
+        assert 400 in responses
+        examples = responses[400]["content"]["application/json"]["examples"]
+        assert "ERR-A" in examples
+        assert "ERR-B" in examples
+        assert examples["ERR-A"]["value"]["message"] == "Bad A"
+        assert examples["ERR-B"]["value"]["message"] == "Bad B"
+
+    def test_two_errors_same_code_single_top_level_entry(self):
+        """Two exceptions with the same HTTP code produce exactly one top-level entry."""
+
+        class BadRequestA(ApiException):
+            api_error = ApiError(
+                code=400, msg="Bad A", desc="Reason A.", err_code="ERR-A"
+            )
+
+        class BadRequestB(ApiException):
+            api_error = ApiError(
+                code=400, msg="Bad B", desc="Reason B.", err_code="ERR-B"
+            )
+
+        responses = generate_error_responses(BadRequestA, BadRequestB)
+        assert len([k for k in responses if k == 400]) == 1
+
+
+class TestInitExceptionsHandlers:
+    """Tests for init_exceptions_handlers function."""
+
+    def test_returns_app(self):
+        """Returns the FastAPI app."""
+        app = FastAPI()
+        result = init_exceptions_handlers(app)
+        assert result is app
+
+    def test_handles_api_exception(self):
+        """Handles ApiException with structured response."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/error")
+        async def raise_error():
+            raise NotFoundError()
+
+        client = TestClient(app)
+        response = client.get("/error")
+
+        assert response.status_code == 404
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "RES-404"
+        assert data["message"] == "Not Found"
+
+    def test_handles_api_exception_without_data(self):
+        """ApiException without data returns null data field."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/error")
+        async def raise_error():
+            raise NotFoundError()
+
+        client = TestClient(app)
+        response = client.get("/error")
+
+        assert response.status_code == 404
+        assert response.json()["data"] is None
+
+    def test_handles_api_exception_with_data(self):
+        """ApiException with data returns the data payload."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        class CustomValidationError(ApiException):
+            api_error = ApiError(
+                code=422,
+                msg="Validation Error",
+                desc="1 validation error(s) detected",
+                err_code="CUSTOM-422",
+                data={
+                    "errors": [
+                        {
+                            "field": "email",
+                            "message": "invalid format",
+                            "type": "value_error",
+                        }
+                    ]
+                },
+            )
+
+        @app.get("/error")
+        async def raise_error():
+            raise CustomValidationError()
+
+        client = TestClient(app)
+        response = client.get("/error")
+
+        assert response.status_code == 422
+        data = response.json()
+        assert data["data"] == {
+            "errors": [
+                {"field": "email", "message": "invalid format", "type": "value_error"}
+            ]
+        }
+        assert data["error_code"] == "CUSTOM-422"
+
+    def test_handles_validation_error(self):
+        """Handles validation errors with structured response."""
+        from pydantic import BaseModel
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        class Item(BaseModel):
+            name: str
+            price: float
+
+        @app.post("/items")
+        async def create_item(item: Item):
+            return item
+
+        client = TestClient(app)
+        response = client.post("/items", json={"name": 123})
+
+        assert response.status_code == 422
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "VAL-422"
+        assert "errors" in data["data"]
+
+    def test_handles_generic_exception(self):
+        """Handles unhandled exceptions with 500 response."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/crash")
+        async def crash():
+            raise RuntimeError("Something went wrong")
+
+        client = TestClient(app, raise_server_exceptions=False)
+        response = client.get("/crash")
+
+        assert response.status_code == 500
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "SERVER-500"
+
+    def test_handles_http_exception(self):
+        """Handles starlette HTTPException with consistent ErrorResponse envelope."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/protected")
+        async def protected():
+            raise HTTPException(status_code=403, detail="Forbidden")
+
+        client = TestClient(app)
+        response = client.get("/protected")
+
+        assert response.status_code == 403
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "HTTP-403"
+        assert data["message"] == "Forbidden"
+
+    def test_handles_http_exception_404_from_route(self):
+        """HTTPException(404) raised inside a route uses the consistent ErrorResponse envelope."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/items/{item_id}")
+        async def get_item(item_id: int):
+            raise HTTPException(status_code=404, detail="Item not found")
+
+        client = TestClient(app)
+        response = client.get("/items/99")
+
+        assert response.status_code == 404
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "HTTP-404"
+        assert data["message"] == "Item not found"
+
+    def test_handles_http_exception_forwards_headers(self):
+        """HTTPException with WWW-Authenticate header forwards it in the response."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/secure")
+        async def secure():
+            raise HTTPException(
+                status_code=401,
+                detail="Not authenticated",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+
+        client = TestClient(app)
+        response = client.get("/secure")
+
+        assert response.status_code == 401
+        assert response.headers.get("www-authenticate") == "Bearer"
+
+    def test_custom_openapi_schema(self):
+        """Customises OpenAPI schema for 422 responses using named examples."""
+        from pydantic import BaseModel
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        class Item(BaseModel):
+            name: str
+
+        @app.post("/items")
+        async def create_item(item: Item):
+            return item
+
+        openapi = app.openapi()
+
+        post_op = openapi["paths"]["/items"]["post"]
+        assert "422" in post_op["responses"]
+        resp_422 = post_op["responses"]["422"]
+        examples = resp_422["content"]["application/json"]["examples"]
+        assert "VAL-422" in examples
+        assert examples["VAL-422"]["value"]["error_code"] == "VAL-422"
+
+    def test_custom_openapi_preserves_app_metadata(self):
+        """_patched_openapi preserves custom FastAPI app-level metadata."""
+        app = FastAPI(
+            title="My API",
+            version="2.0.0",
+            description="Custom description",
+        )
+        init_exceptions_handlers(app)
+
+        schema = app.openapi()
+        assert schema["info"]["title"] == "My API"
+        assert schema["info"]["version"] == "2.0.0"
+
+    def test_handles_response_validation_error(self):
+        """Handles ResponseValidationError with a structured 422 response."""
+        from pydantic import BaseModel
+
+        class CountResponse(BaseModel):
+            count: int
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/broken", response_model=CountResponse)
+        async def broken():
+            return {"count": "not-a-number"}  # triggers ResponseValidationError
+
+        client = TestClient(app, raise_server_exceptions=False)
+        response = client.get("/broken")
+
+        assert response.status_code == 422
+        data = response.json()
+        assert data["status"] == "FAIL"
+        assert data["error_code"] == "VAL-422"
+        assert "errors" in data["data"]
+
+    def test_handles_validation_error_with_non_standard_loc(self):
+        """Validation error with empty loc tuple maps the field to 'root'."""
+        from fastapi.exceptions import RequestValidationError
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/root-error")
+        async def root_error():
+            raise RequestValidationError(
+                [
+                    {
+                        "type": "custom",
+                        "loc": (),
+                        "msg": "root level error",
+                        "input": None,
+                        "url": "",
+                    }
+                ]
+            )
+
+        client = TestClient(app)
+        response = client.get("/root-error")
+
+        assert response.status_code == 422
+        data = response.json()
+        assert data["data"]["errors"][0]["field"] == "root"
+
+    def test_openapi_schema_cached_after_first_call(self):
+        """app.openapi() returns the cached schema on subsequent calls."""
+        from pydantic import BaseModel
+
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        class Item(BaseModel):
+            name: str
+
+        @app.post("/items")
+        async def create_item(item: Item):
+            return item
+
+        schema_first = app.openapi()
+        schema_second = app.openapi()
+        assert schema_first is schema_second
+
+    def test_openapi_skips_operations_without_422(self):
+        """_patched_openapi leaves operations that have no 422 response unchanged."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/ping")
+        async def ping():
+            return {"ok": True}
+
+        schema = app.openapi()
+        get_op = schema["paths"]["/ping"]["get"]
+        assert "422" not in get_op["responses"]
+        assert "200" in get_op["responses"]
+
+    def test_openapi_skips_non_dict_path_item_values(self):
+        """_patched_openapi ignores non-dict values in path items (e.g. path-level parameters)."""
+        from fastapi_toolsets.exceptions.handler import _patched_openapi
+
+        app = FastAPI()
+
+        def fake_openapi() -> dict:
+            return {
+                "paths": {
+                    "/items": {
+                        "parameters": [
+                            {"name": "q", "in": "query"}
+                        ],  # list, not a dict
+                        "get": {"responses": {"200": {"description": "OK"}}},
+                    }
+                }
+            }
+
+        schema = _patched_openapi(app, fake_openapi)
+        # The list value was skipped without error; the GET operation is intact
+        assert schema["paths"]["/items"]["parameters"] == [{"name": "q", "in": "query"}]
+        assert "422" not in schema["paths"]["/items"]["get"]["responses"]
+
+
+class TestExceptionIntegration:
+    """Integration tests for exception handling."""
+
+    @pytest.fixture
+    def app_with_routes(self):
+        """Create app with test routes."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/users/{user_id}")
+        async def get_user(user_id: int):
+            if user_id == 404:
+                raise NotFoundError()
+            if user_id == 401:
+                raise UnauthorizedError()
+            if user_id == 403:
+                raise ForbiddenError()
+            if user_id == 409:
+                raise ConflictError()
+            return {"id": user_id}
+
+        return app
+
+    def test_not_found_response(self, app_with_routes):
+        """NotFoundError returns 404."""
+        client = TestClient(app_with_routes)
+        response = client.get("/users/404")
+
+        assert response.status_code == 404
+        assert response.json()["error_code"] == "RES-404"
+
+    def test_unauthorized_response(self, app_with_routes):
+        """UnauthorizedError returns 401."""
+        client = TestClient(app_with_routes)
+        response = client.get("/users/401")
+
+        assert response.status_code == 401
+        assert response.json()["error_code"] == "AUTH-401"
+
+    def test_forbidden_response(self, app_with_routes):
+        """ForbiddenError returns 403."""
+        client = TestClient(app_with_routes)
+        response = client.get("/users/403")
+
+        assert response.status_code == 403
+        assert response.json()["error_code"] == "AUTH-403"
+
+    def test_conflict_response(self, app_with_routes):
+        """ConflictError returns 409."""
+        client = TestClient(app_with_routes)
+        response = client.get("/users/409")
+
+        assert response.status_code == 409
+        assert response.json()["error_code"] == "RES-409"
+
+    def test_success_response(self, app_with_routes):
+        """Successful requests return normally."""
+        client = TestClient(app_with_routes)
+        response = client.get("/users/1")
+
+        assert response.status_code == 200
+        assert response.json() == {"id": 1}
+
+
+class TestInvalidOrderFieldError:
+    """Tests for InvalidOrderFieldError exception."""
+
+    def test_api_error_attributes(self):
+        """InvalidOrderFieldError has correct api_error metadata."""
+        assert InvalidOrderFieldError.api_error.code == 422
+        assert InvalidOrderFieldError.api_error.err_code == "SORT-422"
+        assert InvalidOrderFieldError.api_error.msg == "Invalid Order Field"
+
+    def test_stores_field_and_valid_fields(self):
+        """InvalidOrderFieldError stores field and valid_fields on the instance."""
+        error = InvalidOrderFieldError("unknown", ["name", "created_at"])
+        assert error.field == "unknown"
+        assert error.valid_fields == ["name", "created_at"]
+
+    def test_description_contains_field_and_valid_fields(self):
+        """api_error.desc mentions the bad field and valid options."""
+        error = InvalidOrderFieldError("bad_field", ["name", "email"])
+        assert "bad_field" in error.api_error.desc
+        assert "name" in error.api_error.desc
+        assert "email" in error.api_error.desc
+
+    def test_handled_as_422_by_exception_handler(self):
+        """init_exceptions_handlers turns InvalidOrderFieldError into a 422 response."""
+        app = FastAPI()
+        init_exceptions_handlers(app)
+
+        @app.get("/items")
+        async def list_items():
+            raise InvalidOrderFieldError("bad", ["name"])
+
+        client = TestClient(app)
+        response = client.get("/items")
+
+        assert response.status_code == 422
+        data = response.json()
+        assert data["error_code"] == "SORT-422"
+        assert data["status"] == "FAIL"