refactor: simplify and deduplicate across crud, metrics, cli, and

exceptions

docs/examples/pagination-search.md

@@ -1,6 +1,6 @@
 # Pagination & search
 
-This example builds an articles listing endpoint that supports **offset pagination**, **cursor pagination**, **full-text search**, and **faceted filtering** — all from a single `CrudFactory` definition.
+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
 
@@ -16,7 +16,7 @@ This example builds an articles listing endpoint that supports **offset paginati
 
 ## Crud
 
-Declare `facet_fields` and `searchable_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.
+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"
@@ -46,14 +46,14 @@ Declare `facet_fields` and `searchable_fields` once on [`CrudFactory`](../refere
 
 Best for admin panels or any UI that needs a total item count and numbered pages.
 
-```python title="routes.py:1:27"
+```python title="routes.py:1:36"
---8<-- "docs_src/examples/pagination_search/routes.py:1:27"
+--8<-- "docs_src/examples/pagination_search/routes.py:1:36"
 ```
 
 **Example request**
 
 ```
-GET /articles/offset?page=2&items_per_page=10&search=fastapi&status=published
+GET /articles/offset?page=2&items_per_page=10&search=fastapi&status=published&order_by=title&order=asc
 ```
 
 **Example response**
@@ -83,14 +83,14 @@ GET /articles/offset?page=2&items_per_page=10&search=fastapi&status=published
 
 Best for feeds, infinite scroll, or any high-throughput API where offset performance degrades.
 
-```python title="routes.py:30:45"
+```python title="routes.py:39:59"
---8<-- "docs_src/examples/pagination_search/routes.py:30:45"
+--8<-- "docs_src/examples/pagination_search/routes.py:39:59"
 ```
 
 **Example request**
 
 ```
-GET /articles/cursor?items_per_page=10&status=published
+GET /articles/cursor?items_per_page=10&status=published&order_by=created_at&order=desc
 ```
 
 **Example response**

docs/module/crud.md

@@ -292,6 +292,8 @@ Use `filter_by` to pass the client's chosen filter values directly — no need t
 Use [`filter_params()`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.filter_params) to generate a dict with the facet filter values from the query parameters:
 
 ```python
+from typing import Annotated
+
 from fastapi import Depends
 
 UserCrud = CrudFactory(
@@ -303,7 +305,7 @@ UserCrud = CrudFactory(
 async def list_users(
     session: SessionDep,
     page: int = 1,
-    filter_by: dict[str, list[str]] = Depends(UserCrud.filter_params()),
+    filter_by: Annotated[dict[str, list[str]], Depends(UserCrud.filter_params())],
 ) -> PaginatedResponse[UserRead]:
     return await UserCrud.offset_paginate(
         session=session,
@@ -320,6 +322,58 @@ GET /users?status=active&country=FR   → filter_by={"status": ["active"], "coun
 GET /users?role=admin&role=editor     → filter_by={"role": ["admin", "editor"]}  (IN clause)
 ```
 
+## Sorting
+
+!!! info "Added in `v1.3`"
+
+Declare `order_fields` on the CRUD class to expose client-driven column ordering via `order_by` and `order` query parameters.
+
+```python
+UserCrud = CrudFactory(
+    model=User,
+    order_fields=[
+        User.name,
+        User.created_at,
+    ],
+)
+```
+
+Call [`order_params()`](../reference/crud.md#fastapi_toolsets.crud.factory.AsyncCrud.order_params) to generate a FastAPI dependency that maps the query parameters to an [`OrderByClause`](../reference/crud.md#fastapi_toolsets.crud.factory.OrderByClause) expression:
+
+```python
+from typing import Annotated
+
+from fastapi import Depends
+from fastapi_toolsets.crud import OrderByClause
+
+@router.get("")
+async def list_users(
+    session: SessionDep,
+    order_by: Annotated[OrderByClause | None, Depends(UserCrud.order_params())],
+) -> PaginatedResponse[UserRead]:
+    return await UserCrud.offset_paginate(session=session, order_by=order_by)
+```
+
+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=name&order=desc  → ORDER BY users.name DESC
+```
+
+An unknown `order_by` value raises [`InvalidOrderFieldError`](../reference/exceptions.md#fastapi_toolsets.exceptions.exceptions.InvalidOrderFieldError) (HTTP 422).
+
+You can also pass `order_fields` directly to `order_params()` to override the class-level defaults without modifying them:
+
+```python
+UserOrderParams = UserCrud.order_params(order_fields=[User.name])
+```
+
 ## Relationship loading
 
 !!! info "Added in `v1.1`"

docs/reference/exceptions.md

@@ -13,6 +13,7 @@ from fastapi_toolsets.exceptions import (
     ConflictError,
     NoSearchableFieldsError,
     InvalidFacetFilterError,
+    InvalidOrderFieldError,
     generate_error_responses,
     init_exceptions_handlers,
 )
@@ -32,6 +33,8 @@ from fastapi_toolsets.exceptions import (
 
 ## ::: fastapi_toolsets.exceptions.exceptions.InvalidFacetFilterError
 
+## ::: fastapi_toolsets.exceptions.exceptions.InvalidOrderFieldError
+
 ## ::: fastapi_toolsets.exceptions.exceptions.generate_error_responses
 
 ## ::: fastapi_toolsets.exceptions.handler.init_exceptions_handlers

docs_src/examples/pagination_search/app.py

@@ -1,6 +1,9 @@
 from fastapi import FastAPI
 
+from fastapi_toolsets.exceptions import init_exceptions_handlers
+
 from .routes import router
 
 app = FastAPI()
+init_exceptions_handlers(app=app)
 app.include_router(router=router)

docs_src/examples/pagination_search/crud.py

@@ -14,6 +14,8 @@ ArticleCrud = CrudFactory(
         Article.status,
         (Article.category, Category.name),
     ],
+    order_fields=[  # fields exposed for client-driven ordering
+        Article.title,
+        Article.created_at,
+    ],
 )
-
-ArticleFilters = ArticleCrud.filter_params()

docs_src/examples/pagination_search/routes.py

@@ -1,9 +1,13 @@
+from typing import Annotated
+
 from fastapi import APIRouter, Depends, Query
 
+from fastapi_toolsets.crud import OrderByClause
 from fastapi_toolsets.schemas import PaginatedResponse
 
 from .crud import ArticleCrud
 from .db import SessionDep
+from .models import Article
 from .schemas import ArticleRead
 
 router = APIRouter(prefix="/articles")
@@ -12,10 +16,14 @@ router = APIRouter(prefix="/articles")
 @router.get("/offset")
 async def list_articles_offset(
     session: SessionDep,
+    filter_by: Annotated[dict[str, list[str]], Depends(ArticleCrud.filter_params())],
+    order_by: Annotated[
+        OrderByClause | None,
+        Depends(ArticleCrud.order_params(default_field=Article.created_at)),
+    ],
     page: int = Query(1, ge=1),
     items_per_page: int = Query(20, ge=1, le=100),
     search: str | None = None,
-    filter_by: dict[str, list[str]] = Depends(ArticleCrud.filter_params()),
 ) -> PaginatedResponse[ArticleRead]:
     return await ArticleCrud.offset_paginate(
         session=session,
@@ -23,6 +31,7 @@ async def list_articles_offset(
         items_per_page=items_per_page,
         search=search,
         filter_by=filter_by or None,
+        order_by=order_by,
         schema=ArticleRead,
     )
 
@@ -30,10 +39,14 @@ async def list_articles_offset(
 @router.get("/cursor")
 async def list_articles_cursor(
     session: SessionDep,
+    filter_by: Annotated[dict[str, list[str]], Depends(ArticleCrud.filter_params())],
+    order_by: Annotated[
+        OrderByClause | None,
+        Depends(ArticleCrud.order_params(default_field=Article.created_at)),
+    ],
     cursor: str | None = None,
     items_per_page: int = Query(20, ge=1, le=100),
     search: str | None = None,
-    filter_by: dict[str, list[str]] = Depends(ArticleCrud.filter_params()),
 ) -> PaginatedResponse[ArticleRead]:
     return await ArticleCrud.cursor_paginate(
         session=session,
@@ -41,5 +54,6 @@ async def list_articles_cursor(
         items_per_page=items_per_page,
         search=search,
         filter_by=filter_by or None,
+        order_by=order_by,
         schema=ArticleRead,
     )

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "fastapi-toolsets"
-version = "1.2.1"
+version = "1.3.0"
 description = "Production-ready utilities for FastAPI applications"
 readme = "README.md"
 license = "MIT"

src/fastapi_toolsets/__init__.py

@@ -21,4 +21,4 @@ Example usage:
         return Response(data={"user": user.username}, message="Success")
 """
 
-__version__ = "1.2.1"
+__version__ = "1.3.0"

src/fastapi_toolsets/cli/commands/fixtures.py

@@ -72,7 +72,7 @@ async def load(
     registry = get_fixtures_registry()
     db_context = get_db_context()
 
-    context_list = [c.value for c in contexts] if contexts else [Context.BASE]
+    context_list = list(contexts) if contexts else [Context.BASE]
 
     ordered = registry.resolve_context_dependencies(*context_list)
 

src/fastapi_toolsets/crud/__init__.py

@@ -1,12 +1,9 @@
 """Generic async CRUD operations for SQLAlchemy models."""
 
 from ..exceptions import InvalidFacetFilterError, NoSearchableFieldsError
-from .factory import CrudFactory, JoinType, M2MFieldType
+from ..types import FacetFieldType, JoinType, M2MFieldType, OrderByClause
-from .search import (
+from .factory import CrudFactory
-    FacetFieldType,
+from .search import SearchConfig, get_searchable_fields
-    SearchConfig,
-    get_searchable_fields,
-)
 
 __all__ = [
     "CrudFactory",
@@ -16,5 +13,6 @@ __all__ = [
     "JoinType",
     "M2MFieldType",
     "NoSearchableFieldsError",
+    "OrderByClause",
     "SearchConfig",
 ]

src/fastapi_toolsets/crud/factory.py

@@ -6,10 +6,10 @@ import base64
 import inspect
 import json
 import uuid as uuid_module
-from collections.abc import Awaitable, Callable, Mapping, Sequence
+from collections.abc import Awaitable, Callable, Sequence
 from datetime import date, datetime
 from decimal import Decimal
-from typing import Any, ClassVar, Generic, Literal, Self, TypeVar, cast, overload
+from typing import Any, ClassVar, Generic, Literal, Self, cast, overload
 
 from fastapi import Query
 from pydantic import BaseModel
@@ -23,23 +23,25 @@ from sqlalchemy.sql.base import ExecutableOption
 from sqlalchemy.sql.roles import WhereHavingRole
 
 from ..db import get_transaction
-from ..exceptions import NotFoundError
+from ..exceptions import InvalidOrderFieldError, NotFoundError
 from ..schemas import CursorPagination, OffsetPagination, PaginatedResponse, Response
-from .search import (
+from ..types import (
     FacetFieldType,
-    SearchConfig,
+    JoinType,
+    M2MFieldType,
+    ModelType,
+    OrderByClause,
+    SchemaType,
     SearchFieldType,
+)
+from .search import (
+    SearchConfig,
     build_facets,
     build_filter_by,
     build_search_filters,
     facet_keys,
 )
 
-ModelType = TypeVar("ModelType", bound=DeclarativeBase)
-SchemaType = TypeVar("SchemaType", bound=BaseModel)
-JoinType = list[tuple[type[DeclarativeBase], Any]]
-M2MFieldType = Mapping[str, QueryableAttribute[Any]]
-
 
 def _encode_cursor(value: Any) -> str:
     """Encode cursor column value as an base64 string."""
@@ -51,6 +53,22 @@ def _decode_cursor(cursor: str) -> str:
     return json.loads(base64.b64decode(cursor.encode()).decode())
 
 
+def _apply_joins(q: Any, joins: JoinType | None, outer_join: bool) -> Any:
+    """Apply a list of (model, condition) joins to a SQLAlchemy select query."""
+    if not joins:
+        return q
+    for model, condition in joins:
+        q = q.outerjoin(model, condition) if outer_join else q.join(model, condition)
+    return q
+
+
+def _apply_search_joins(q: Any, search_joins: list[Any]) -> Any:
+    """Apply relationship-based outer joins (from search/filter_by) to a query."""
+    for join_rel in search_joins:
+        q = q.outerjoin(join_rel)
+    return q
+
+
 class AsyncCrud(Generic[ModelType]):
     """Generic async CRUD operations for SQLAlchemy models.
 
@@ -60,6 +78,7 @@ class AsyncCrud(Generic[ModelType]):
     model: ClassVar[type[DeclarativeBase]]
     searchable_fields: ClassVar[Sequence[SearchFieldType] | None] = None
     facet_fields: ClassVar[Sequence[FacetFieldType] | None] = None
+    order_fields: ClassVar[Sequence[QueryableAttribute[Any]] | None] = None
     m2m_fields: ClassVar[M2MFieldType | None] = None
     default_load_options: ClassVar[list[ExecutableOption] | None] = None
     cursor_column: ClassVar[Any | None] = None
@@ -129,6 +148,48 @@ class AsyncCrud(Generic[ModelType]):
             return set()
         return set(cls.m2m_fields.keys())
 
+    @classmethod
+    def _resolve_facet_fields(
+        cls: type[Self],
+        facet_fields: Sequence[FacetFieldType] | None,
+    ) -> Sequence[FacetFieldType] | None:
+        """Return facet_fields if given, otherwise fall back to the class-level default."""
+        return facet_fields if facet_fields is not None else cls.facet_fields
+
+    @classmethod
+    def _prepare_filter_by(
+        cls: type[Self],
+        filter_by: dict[str, Any] | BaseModel | None,
+        facet_fields: Sequence[FacetFieldType] | None,
+    ) -> tuple[list[Any], list[Any]]:
+        """Normalize filter_by and return (filters, joins) to apply to the query."""
+        if isinstance(filter_by, BaseModel):
+            filter_by = filter_by.model_dump(exclude_none=True)
+        if not filter_by:
+            return [], []
+        resolved = cls._resolve_facet_fields(facet_fields)
+        return build_filter_by(filter_by, resolved or [])
+
+    @classmethod
+    async def _build_filter_attributes(
+        cls: type[Self],
+        session: AsyncSession,
+        facet_fields: Sequence[FacetFieldType] | None,
+        filters: list[Any],
+        search_joins: list[Any],
+    ) -> dict[str, list[Any]] | None:
+        """Build facet filter_attributes, or return None if no facet fields configured."""
+        resolved = cls._resolve_facet_fields(facet_fields)
+        if not resolved:
+            return None
+        return await build_facets(
+            session,
+            cls.model,
+            resolved,
+            base_filters=filters,
+            base_joins=search_joins,
+        )
+
     @classmethod
     def filter_params(
         cls: type[Self],
@@ -149,7 +210,7 @@ class AsyncCrud(Generic[ModelType]):
             ValueError: If no facet fields are configured on this CRUD class and none are
                 provided via ``facet_fields``.
         """
-        fields = facet_fields if facet_fields is not None else cls.facet_fields
+        fields = cls._resolve_facet_fields(facet_fields)
         if not fields:
             raise ValueError(
                 f"{cls.__name__} has no facet_fields configured. "
@@ -175,6 +236,63 @@ class AsyncCrud(Generic[ModelType]):
 
         return dependency
 
+    @classmethod
+    def order_params(
+        cls: type[Self],
+        *,
+        order_fields: Sequence[QueryableAttribute[Any]] | None = None,
+        default_field: QueryableAttribute[Any] | None = None,
+        default_order: Literal["asc", "desc"] = "asc",
+    ) -> Callable[..., Awaitable[OrderByClause | None]]:
+        """Return a FastAPI dependency that resolves order query params into an order_by clause.
+
+        Args:
+            order_fields: Override the allowed order fields. Falls back to the class-level
+                ``order_fields`` if not provided.
+            default_field: Field to order by when ``order_by`` query param is absent.
+                If ``None`` and no ``order_by`` is provided, no ordering is applied.
+            default_order: Default order direction when ``order`` is absent
+                (``"asc"`` or ``"desc"``).
+
+        Returns:
+            An async dependency function named ``{Model}OrderParams`` that resolves to an
+            ``OrderByClause`` (or ``None``). Pass it to ``Depends()`` in your route.
+
+        Raises:
+            ValueError: If no order fields are configured on this CRUD class and none are
+                provided via ``order_fields``.
+            InvalidOrderFieldError: When the request provides an unknown ``order_by`` value.
+        """
+        fields = order_fields if order_fields is not None else cls.order_fields
+        if not fields:
+            raise ValueError(
+                f"{cls.__name__} has no order_fields configured. "
+                "Pass order_fields= or set them on CrudFactory."
+            )
+        field_map: dict[str, QueryableAttribute[Any]] = {f.key: f for f in fields}
+        valid_keys = sorted(field_map.keys())
+
+        async def dependency(
+            order_by: str | None = Query(
+                None, description=f"Field to order by. Valid values: {valid_keys}"
+            ),
+            order: Literal["asc", "desc"] = Query(
+                default_order, description="Sort direction"
+            ),
+        ) -> OrderByClause | None:
+            if order_by is None:
+                if default_field is None:
+                    return None
+                field = default_field
+            elif order_by not in field_map:
+                raise InvalidOrderFieldError(order_by, valid_keys)
+            else:
+                field = field_map[order_by]
+            return field.asc() if order == "asc" else field.desc()
+
+        dependency.__name__ = f"{cls.model.__name__}OrderParams"
+        return dependency
+
     @overload
     @classmethod
     async def create(  # pragma: no cover
@@ -230,8 +348,7 @@ class AsyncCrud(Generic[ModelType]):
         await session.refresh(db_model)
         result = cast(ModelType, db_model)
         if schema:
-            data_out = schema.model_validate(result) if schema else result
+            return Response(data=schema.model_validate(result))
-            return Response(data=data_out)
         return result
 
     @overload
@@ -294,13 +411,7 @@ class AsyncCrud(Generic[ModelType]):
             MultipleResultsFound: If more than one record found
         """
         q = select(cls.model)
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
         q = q.where(and_(*filters))
         if resolved := cls._resolve_load_options(load_options):
             q = q.options(*resolved)
@@ -312,8 +423,7 @@ class AsyncCrud(Generic[ModelType]):
             raise NotFoundError()
         result = cast(ModelType, item)
         if schema:
-            data_out = schema.model_validate(result) if schema else result
+            return Response(data=schema.model_validate(result))
-            return Response(data=data_out)
         return result
 
     @classmethod
@@ -339,13 +449,7 @@ class AsyncCrud(Generic[ModelType]):
             Model instance or None
         """
         q = select(cls.model)
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
         if filters:
             q = q.where(and_(*filters))
         if resolved := cls._resolve_load_options(load_options):
@@ -362,7 +466,7 @@ class AsyncCrud(Generic[ModelType]):
         joins: JoinType | None = None,
         outer_join: bool = False,
         load_options: list[ExecutableOption] | None = None,
-        order_by: Any | None = None,
+        order_by: OrderByClause | None = None,
         limit: int | None = None,
         offset: int | None = None,
     ) -> Sequence[ModelType]:
@@ -382,13 +486,7 @@ class AsyncCrud(Generic[ModelType]):
             List of model instances
         """
         q = select(cls.model)
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
         if filters:
             q = q.where(and_(*filters))
         if resolved := cls._resolve_load_options(load_options):
@@ -486,8 +584,7 @@ class AsyncCrud(Generic[ModelType]):
                     setattr(db_model, rel_attr, related_instances)
         await session.refresh(db_model)
         if schema:
-            data_out = schema.model_validate(db_model) if schema else db_model
+            return Response(data=schema.model_validate(db_model))
-            return Response(data=data_out)
         return db_model
 
     @classmethod
@@ -604,13 +701,7 @@ class AsyncCrud(Generic[ModelType]):
             Number of matching records
         """
         q = select(func.count()).select_from(cls.model)
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
         if filters:
             q = q.where(and_(*filters))
         result = await session.execute(q)
@@ -637,13 +728,7 @@ class AsyncCrud(Generic[ModelType]):
             True if at least one record matches
         """
         q = select(cls.model)
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
         q = q.where(and_(*filters)).exists().select()
         result = await session.execute(q)
         return bool(result.scalar())
@@ -657,7 +742,7 @@ class AsyncCrud(Generic[ModelType]):
         joins: JoinType | None = None,
         outer_join: bool = False,
         load_options: list[ExecutableOption] | None = None,
-        order_by: Any | None = None,
+        order_by: OrderByClause | None = None,
         page: int = 1,
         items_per_page: int = 20,
         search: str | SearchConfig | None = None,
@@ -690,47 +775,29 @@ class AsyncCrud(Generic[ModelType]):
         """
         filters = list(filters) if filters else []
         offset = (page - 1) * items_per_page
-        search_joins: list[Any] = []
 
-        if isinstance(filter_by, BaseModel):
+        fb_filters, search_joins = cls._prepare_filter_by(filter_by, facet_fields)
-            filter_by = filter_by.model_dump(exclude_none=True) or None
+        filters.extend(fb_filters)
-
-        # Build filter_by conditions from declared facet fields
-        if filter_by:
-            resolved_facets_for_filter = (
-                facet_fields if facet_fields is not None else cls.facet_fields
-            )
-            fb_filters, fb_joins = build_filter_by(
-                filter_by, resolved_facets_for_filter or []
-            )
-            filters.extend(fb_filters)
-            search_joins.extend(fb_joins)
 
         # Build search filters
         if search:
-            search_filters, search_joins = build_search_filters(
+            search_filters, new_search_joins = build_search_filters(
                 cls.model,
                 search,
                 search_fields=search_fields,
                 default_fields=cls.searchable_fields,
             )
             filters.extend(search_filters)
+            search_joins.extend(new_search_joins)
 
         # Build query with joins
         q = select(cls.model)
 
         # Apply explicit joins
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
 
         # Apply search joins (always outer joins for search)
-        for join_rel in search_joins:
+        q = _apply_search_joins(q, search_joins)
-            q = q.outerjoin(join_rel)
 
         if filters:
             q = q.where(and_(*filters))
@@ -750,17 +817,10 @@ class AsyncCrud(Generic[ModelType]):
         count_q = count_q.select_from(cls.model)
 
         # Apply explicit joins to count query
-        if joins:
+        count_q = _apply_joins(count_q, joins, outer_join)
-            for model, condition in joins:
-                count_q = (
-                    count_q.outerjoin(model, condition)
-                    if outer_join
-                    else count_q.join(model, condition)
-                )
 
         # Apply search joins to count query
-        for join_rel in search_joins:
+        count_q = _apply_search_joins(count_q, search_joins)
-            count_q = count_q.outerjoin(join_rel)
 
         if filters:
             count_q = count_q.where(and_(*filters))
@@ -768,19 +828,9 @@ class AsyncCrud(Generic[ModelType]):
         count_result = await session.execute(count_q)
         total_count = count_result.scalar_one()
 
-        # Build facets
+        filter_attributes = await cls._build_filter_attributes(
-        resolved_facet_fields = (
+            session, facet_fields, filters, search_joins
-            facet_fields if facet_fields is not None else cls.facet_fields
         )
-        filter_attributes: dict[str, list[Any]] | None = None
-        if resolved_facet_fields:
-            filter_attributes = await build_facets(
-                session,
-                cls.model,
-                resolved_facet_fields,
-                base_filters=filters or None,
-                base_joins=search_joins or None,
-            )
 
         return PaginatedResponse(
             data=items,
@@ -803,7 +853,7 @@ class AsyncCrud(Generic[ModelType]):
         joins: JoinType | None = None,
         outer_join: bool = False,
         load_options: list[ExecutableOption] | None = None,
-        order_by: Any | None = None,
+        order_by: OrderByClause | None = None,
         items_per_page: int = 20,
         search: str | SearchConfig | None = None,
         search_fields: Sequence[SearchFieldType] | None = None,
@@ -837,21 +887,9 @@ class AsyncCrud(Generic[ModelType]):
             PaginatedResponse with CursorPagination metadata
         """
         filters = list(filters) if filters else []
-        search_joins: list[Any] = []
 
-        if isinstance(filter_by, BaseModel):
+        fb_filters, search_joins = cls._prepare_filter_by(filter_by, facet_fields)
-            filter_by = filter_by.model_dump(exclude_none=True) or None
+        filters.extend(fb_filters)
-
-        # Build filter_by conditions from declared facet fields
-        if filter_by:
-            resolved_facets_for_filter = (
-                facet_fields if facet_fields is not None else cls.facet_fields
-            )
-            fb_filters, fb_joins = build_filter_by(
-                filter_by, resolved_facets_for_filter or []
-            )
-            filters.extend(fb_filters)
-            search_joins.extend(fb_joins)
 
         if cls.cursor_column is None:
             raise ValueError(
@@ -884,29 +922,23 @@ class AsyncCrud(Generic[ModelType]):
 
         # Build search filters
         if search:
-            search_filters, search_joins = build_search_filters(
+            search_filters, new_search_joins = build_search_filters(
                 cls.model,
                 search,
                 search_fields=search_fields,
                 default_fields=cls.searchable_fields,
             )
             filters.extend(search_filters)
+            search_joins.extend(new_search_joins)
 
         # Build query
         q = select(cls.model)
 
         # Apply explicit joins
-        if joins:
+        q = _apply_joins(q, joins, outer_join)
-            for model, condition in joins:
-                q = (
-                    q.outerjoin(model, condition)
-                    if outer_join
-                    else q.join(model, condition)
-                )
 
         # Apply search joins (always outer joins)
-        for join_rel in search_joins:
+        q = _apply_search_joins(q, search_joins)
-            q = q.outerjoin(join_rel)
 
         if filters:
             q = q.where(and_(*filters))
@@ -938,19 +970,9 @@ class AsyncCrud(Generic[ModelType]):
 
         items: list[Any] = [schema.model_validate(item) for item in items_page]
 
-        # Build facets
+        filter_attributes = await cls._build_filter_attributes(
-        resolved_facet_fields = (
+            session, facet_fields, filters, search_joins
-            facet_fields if facet_fields is not None else cls.facet_fields
         )
-        filter_attributes: dict[str, list[Any]] | None = None
-        if resolved_facet_fields:
-            filter_attributes = await build_facets(
-                session,
-                cls.model,
-                resolved_facet_fields,
-                base_filters=filters or None,
-                base_joins=search_joins or None,
-            )
 
         return PaginatedResponse(
             data=items,
@@ -969,6 +991,7 @@ def CrudFactory(
     *,
     searchable_fields: Sequence[SearchFieldType] | None = None,
     facet_fields: Sequence[FacetFieldType] | None = None,
+    order_fields: Sequence[QueryableAttribute[Any]] | None = None,
     m2m_fields: M2MFieldType | None = None,
     default_load_options: list[ExecutableOption] | None = None,
     cursor_column: Any | None = None,
@@ -981,6 +1004,8 @@ def CrudFactory(
         facet_fields: Optional list of columns to compute distinct values for in paginated
             responses. Supports direct columns (``User.status``) and relationship tuples
             (``(User.role, Role.name)``). Can be overridden per call.
+        order_fields: Optional list of model attributes that callers are allowed to order by
+            via ``order_params()``. Can be overridden per call.
         m2m_fields: Optional mapping for many-to-many relationships.
             Maps schema field names (containing lists of IDs) to
             SQLAlchemy relationship attributes.
@@ -1074,6 +1099,7 @@ def CrudFactory(
             "model": model,
             "searchable_fields": searchable_fields,
             "facet_fields": facet_fields,
+            "order_fields": order_fields,
             "m2m_fields": m2m_fields,
             "default_load_options": default_load_options,
             "cursor_column": cursor_column,

src/fastapi_toolsets/crud/search.py

@@ -1,24 +1,23 @@
 """Search utilities for AsyncCrud."""
 
 import asyncio
+import functools
 from collections import Counter
 from collections.abc import Sequence
-from dataclasses import dataclass
+from dataclasses import dataclass, replace
 from typing import TYPE_CHECKING, Any, Literal
 
-from sqlalchemy import String, or_, select
+from sqlalchemy import String, and_, or_, select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import DeclarativeBase
 from sqlalchemy.orm.attributes import InstrumentedAttribute
 
 from ..exceptions import InvalidFacetFilterError, NoSearchableFieldsError
+from ..types import FacetFieldType, SearchFieldType
 
 if TYPE_CHECKING:
     from sqlalchemy.sql.elements import ColumnElement
 
-SearchFieldType = InstrumentedAttribute[Any] | tuple[InstrumentedAttribute[Any], ...]
-FacetFieldType = SearchFieldType
-
 
 @dataclass
 class SearchConfig:
@@ -37,6 +36,7 @@ class SearchConfig:
     match_mode: Literal["any", "all"] = "any"
 
 
+@functools.lru_cache(maxsize=128)
 def get_searchable_fields(
     model: type[DeclarativeBase],
     *,
@@ -101,14 +101,11 @@ def build_search_filters(
     if isinstance(search, str):
         config = SearchConfig(query=search, fields=search_fields)
     else:
-        config = search
+        config = (
-        if search_fields is not None:
+            replace(search, fields=search_fields)
-            config = SearchConfig(
+            if search_fields is not None
-                query=config.query,
+            else search
-                fields=search_fields,
+        )
-                case_sensitive=config.case_sensitive,
-                match_mode=config.match_mode,
-            )
 
     if not config.query or not config.query.strip():
         return [], []
@@ -227,8 +224,6 @@ async def build_facets(
                 q = q.outerjoin(rel)
 
         if base_filters:
-            from sqlalchemy import and_
-
             q = q.where(and_(*base_filters))
 
         q = q.order_by(column)

src/fastapi_toolsets/dependencies.py

@@ -1,20 +1,17 @@
 """Dependency factories for FastAPI routes."""
 
 import inspect
-from collections.abc import AsyncGenerator, Callable
+from collections.abc import Callable
-from typing import Any, TypeVar, cast
+from typing import Any, cast
 
 from fastapi import Depends
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy.orm import DeclarativeBase
 
 from .crud import CrudFactory
+from .types import ModelType, SessionDependency
 
 __all__ = ["BodyDependency", "PathDependency"]
 
-ModelType = TypeVar("ModelType", bound=DeclarativeBase)
-SessionDependency = Callable[[], AsyncGenerator[AsyncSession, None]]
-
 
 def PathDependency(
     model: type[ModelType],

src/fastapi_toolsets/exceptions/__init__.py

@@ -6,6 +6,7 @@ from .exceptions import (
     ConflictError,
     ForbiddenError,
     InvalidFacetFilterError,
+    InvalidOrderFieldError,
     NoSearchableFieldsError,
     NotFoundError,
     UnauthorizedError,
@@ -21,6 +22,7 @@ __all__ = [
     "generate_error_responses",
     "init_exceptions_handlers",
     "InvalidFacetFilterError",
+    "InvalidOrderFieldError",
     "NoSearchableFieldsError",
     "NotFoundError",
     "UnauthorizedError",

src/fastapi_toolsets/exceptions/exceptions.py

@@ -128,6 +128,31 @@ class InvalidFacetFilterError(ApiException):
         super().__init__(detail)
 
 
+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
+        detail = (
+            f"'{field}' is not an allowed order field. Valid fields: {valid_fields}."
+        )
+        super().__init__(detail)
+
+
 def generate_error_responses(
     *errors: type[ApiException],
 ) -> dict[int | str, dict[str, Any]]:

src/fastapi_toolsets/exceptions/handler.py

@@ -10,6 +10,10 @@ 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.
@@ -106,9 +110,7 @@ def _format_validation_error(
 
     for error in errors:
         field_path = ".".join(
-            str(loc)
+            str(loc) for loc in error["loc"] if loc not in _VALIDATION_LOCATION_PARAMS
-            for loc in error["loc"]
-            if loc not in ("body", "query", "path", "header", "cookie")
         )
         formatted_errors.append(
             {

src/fastapi_toolsets/fixtures/utils.py

@@ -1,24 +1,84 @@
 """Fixture loading utilities for database seeding."""
 
 from collections.abc import Callable, Sequence
-from typing import Any, TypeVar
+from typing import Any
 
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import DeclarativeBase
 
 from ..db import get_transaction
 from ..logger import get_logger
+from ..types import ModelType
 from .enum import LoadStrategy
 from .registry import Context, FixtureRegistry
 
 logger = get_logger()
 
-T = TypeVar("T", bound=DeclarativeBase)
+
+async def _load_ordered(
+    session: AsyncSession,
+    registry: FixtureRegistry,
+    ordered_names: list[str],
+    strategy: LoadStrategy,
+) -> dict[str, list[DeclarativeBase]]:
+    """Load fixtures in order."""
+    results: dict[str, list[DeclarativeBase]] = {}
+
+    for name in ordered_names:
+        fixture = registry.get(name)
+        instances = list(fixture.func())
+
+        if not instances:
+            results[name] = []
+            continue
+
+        model_name = type(instances[0]).__name__
+        loaded: list[DeclarativeBase] = []
+
+        async with get_transaction(session):
+            for instance in instances:
+                if strategy == LoadStrategy.INSERT:
+                    session.add(instance)
+                    loaded.append(instance)
+
+                elif strategy == LoadStrategy.MERGE:
+                    merged = await session.merge(instance)
+                    loaded.append(merged)
+
+                else:  # LoadStrategy.SKIP_EXISTING
+                    pk = _get_primary_key(instance)
+                    if pk is not None:
+                        existing = await session.get(type(instance), pk)
+                        if existing is None:
+                            session.add(instance)
+                            loaded.append(instance)
+                    else:
+                        session.add(instance)
+                        loaded.append(instance)
+
+        results[name] = loaded
+        logger.info(f"Loaded fixture '{name}': {len(loaded)} {model_name}(s)")
+
+    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
 
 
 def get_obj_by_attr(
-    fixtures: Callable[[], Sequence[T]], attr_name: str, value: Any
+    fixtures: Callable[[], Sequence[ModelType]], attr_name: str, value: Any
-) -> T:
+) -> ModelType:
     """Get a SQLAlchemy model instance by matching an attribute value.
 
     Args:
@@ -57,13 +117,6 @@ async def load_fixtures(
 
     Returns:
         Dict mapping fixture names to loaded instances
-
-    Example:
-        ```python
-        # Loads 'roles' first (dependency), then 'users'
-        result = await load_fixtures(session, fixtures, "users")
-        print(result["users"])  # [User(...), ...]
-        ```
     """
     ordered = registry.resolve_dependencies(*names)
     return await _load_ordered(session, registry, ordered, strategy)
@@ -85,76 +138,6 @@ async def load_fixtures_by_context(
 
     Returns:
         Dict mapping fixture names to loaded instances
-
-    Example:
-        ```python
-        # Load base + testing fixtures
-        await load_fixtures_by_context(
-            session, fixtures,
-            Context.BASE, Context.TESTING
-        )
-        ```
     """
     ordered = registry.resolve_context_dependencies(*contexts)
     return await _load_ordered(session, registry, ordered, strategy)
-
-
-async def _load_ordered(
-    session: AsyncSession,
-    registry: FixtureRegistry,
-    ordered_names: list[str],
-    strategy: LoadStrategy,
-) -> dict[str, list[DeclarativeBase]]:
-    """Load fixtures in order."""
-    results: dict[str, list[DeclarativeBase]] = {}
-
-    for name in ordered_names:
-        fixture = registry.get(name)
-        instances = list(fixture.func())
-
-        if not instances:
-            results[name] = []
-            continue
-
-        model_name = type(instances[0]).__name__
-        loaded: list[DeclarativeBase] = []
-
-        async with get_transaction(session):
-            for instance in instances:
-                if strategy == LoadStrategy.INSERT:
-                    session.add(instance)
-                    loaded.append(instance)
-
-                elif strategy == LoadStrategy.MERGE:
-                    merged = await session.merge(instance)
-                    loaded.append(merged)
-
-                elif strategy == LoadStrategy.SKIP_EXISTING:
-                    pk = _get_primary_key(instance)
-                    if pk is not None:
-                        existing = await session.get(type(instance), pk)
-                        if existing is None:
-                            session.add(instance)
-                            loaded.append(instance)
-                    else:
-                        session.add(instance)
-                        loaded.append(instance)
-
-        results[name] = loaded
-        logger.info(f"Loaded fixture '{name}': {len(loaded)} {model_name}(s)")
-
-    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

src/fastapi_toolsets/metrics/handler.py

@@ -53,17 +53,23 @@ def init_metrics(
         logger.debug("Initialising metric provider '%s'", provider.name)
         provider.func()
 
-    collectors = registry.get_collectors()
+    # 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 asyncio.iscoroutinefunction(c.func)
+    ]
+    sync_collectors = [
+        c for c in registry.get_collectors() if not asyncio.iscoroutinefunction(c.func)
+    ]
+    multiprocess_mode = _is_multiprocess()
 
     @app.get(path, include_in_schema=False)
     async def metrics_endpoint() -> Response:
-        for collector in collectors:
+        for collector in sync_collectors:
-            if asyncio.iscoroutinefunction(collector.func):
+            collector.func()
-                await collector.func()
+        for collector in async_collectors:
-            else:
+            await collector.func()
-                collector.func()
 
-        if _is_multiprocess():
+        if multiprocess_mode:
             prom_registry = CollectorRegistry()
             multiprocess.MultiProcessCollector(prom_registry)
             output = generate_latest(prom_registry)

src/fastapi_toolsets/schemas.py

@@ -1,10 +1,12 @@
 """Base Pydantic schemas for API responses."""
 
 from enum import Enum
-from typing import Any, ClassVar, Generic, TypeVar
+from typing import Any, ClassVar, Generic
 
 from pydantic import BaseModel, ConfigDict
 
+from .types import DataT
+
 __all__ = [
     "ApiError",
     "CursorPagination",
@@ -16,8 +18,6 @@ __all__ = [
     "ResponseStatus",
 ]
 
-DataT = TypeVar("DataT")
-
 
 class PydanticBase(BaseModel):
     """Base class for all Pydantic models with common configuration."""

src/fastapi_toolsets/types.py

@@ -0,0 +1,27 @@
+"""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]]
+M2MFieldType = Mapping[str, QueryableAttribute[Any]]
+OrderByClause = ColumnElement[Any] | QueryableAttribute[Any]
+
+# Search / facet type aliases
+SearchFieldType = InstrumentedAttribute[Any] | tuple[InstrumentedAttribute[Any], ...]
+FacetFieldType = SearchFieldType
+
+# Dependency type aliases
+SessionDependency = Callable[[], AsyncGenerator[AsyncSession, None]]

tests/conftest.py

@@ -92,6 +92,15 @@ class IntRole(Base):
     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."""
 

tests/test_crud_search.py

@@ -1,9 +1,11 @@
 """Tests for CRUD search functionality."""
 
+import inspect
 import uuid
 
 import pytest
 from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.sql.elements import ColumnElement, UnaryExpression
 
 from fastapi_toolsets.crud import (
     CrudFactory,
@@ -11,6 +13,7 @@ from fastapi_toolsets.crud import (
     SearchConfig,
     get_searchable_fields,
 )
+from fastapi_toolsets.exceptions import InvalidOrderFieldError
 from fastapi_toolsets.schemas import OffsetPagination
 
 from .conftest import (
@@ -1046,3 +1049,144 @@ class TestFilterParamsSchema:
 
         assert isinstance(result.pagination, OffsetPagination)
         assert result.pagination.total_count == 2
+
+
+class TestOrderParamsSchema:
+    """Tests for AsyncCrud.order_params()."""
+
+    def test_generates_order_by_and_order_params(self):
+        """Returned dependency has order_by and order query params."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username, User.email])
+        dep = UserOrderCrud.order_params()
+
+        param_names = set(inspect.signature(dep).parameters)
+        assert param_names == {"order_by", "order"}
+
+    def test_dependency_name_includes_model_name(self):
+        """Dependency function is named after the model."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params()
+        assert getattr(dep, "__name__") == "UserOrderParams"
+
+    def test_raises_when_no_order_fields(self):
+        """ValueError raised when no order_fields are configured or provided."""
+        with pytest.raises(ValueError, match="no order_fields"):
+            UserCrud.order_params()
+
+    def test_order_fields_override(self):
+        """order_fields= parameter overrides the class-level default."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username, User.email])
+        dep = UserOrderCrud.order_params(order_fields=[User.email])
+
+        param_names = set(inspect.signature(dep).parameters)
+        assert "order_by" in param_names
+        # description should only mention email, not username
+        sig = inspect.signature(dep)
+        description = sig.parameters["order_by"].default.description
+        assert "email" in description
+        assert "username" not in description
+
+    def test_order_by_description_lists_valid_fields(self):
+        """order_by query param description mentions each allowed field."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username, User.email])
+        dep = UserOrderCrud.order_params()
+
+        sig = inspect.signature(dep)
+        description = sig.parameters["order_by"].default.description
+        assert "username" in description
+        assert "email" in description
+
+    def test_default_order_reflected_in_order_default(self):
+        """default_order is used as the default value for order."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep_asc = UserOrderCrud.order_params(default_order="asc")
+        dep_desc = UserOrderCrud.order_params(default_order="desc")
+
+        sig_asc = inspect.signature(dep_asc)
+        sig_desc = inspect.signature(dep_desc)
+        assert sig_asc.parameters["order"].default.default == "asc"
+        assert sig_desc.parameters["order"].default.default == "desc"
+
+    @pytest.mark.anyio
+    async def test_no_order_by_no_default_returns_none(self):
+        """Returns None when order_by is absent and no default_field is set."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params()
+        result = await dep(order_by=None, order="asc")
+        assert result is None
+
+    @pytest.mark.anyio
+    async def test_no_order_by_with_default_field_returns_asc_expression(self):
+        """Returns default_field.asc() when order_by absent and order=asc."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params(default_field=User.username)
+        result = await dep(order_by=None, order="asc")
+        assert isinstance(result, UnaryExpression)
+        assert "ASC" in str(result)
+
+    @pytest.mark.anyio
+    async def test_no_order_by_with_default_field_returns_desc_expression(self):
+        """Returns default_field.desc() when order_by absent and order=desc."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params(default_field=User.username)
+        result = await dep(order_by=None, order="desc")
+        assert isinstance(result, UnaryExpression)
+        assert "DESC" in str(result)
+
+    @pytest.mark.anyio
+    async def test_valid_order_by_asc(self):
+        """Returns field.asc() for a valid order_by with order=asc."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params()
+        result = await dep(order_by="username", order="asc")
+        assert isinstance(result, UnaryExpression)
+        assert "ASC" in str(result)
+
+    @pytest.mark.anyio
+    async def test_valid_order_by_desc(self):
+        """Returns field.desc() for a valid order_by with order=desc."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params()
+        result = await dep(order_by="username", order="desc")
+        assert isinstance(result, UnaryExpression)
+        assert "DESC" in str(result)
+
+    @pytest.mark.anyio
+    async def test_invalid_order_by_raises_invalid_order_field_error(self):
+        """Raises InvalidOrderFieldError for an unknown order_by value."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        dep = UserOrderCrud.order_params()
+        with pytest.raises(InvalidOrderFieldError) as exc_info:
+            await dep(order_by="nonexistent", order="asc")
+        assert exc_info.value.field == "nonexistent"
+        assert "username" in exc_info.value.valid_fields
+
+    @pytest.mark.anyio
+    async def test_multiple_fields_all_resolve(self):
+        """All configured fields resolve correctly via order_by."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username, User.email])
+        dep = UserOrderCrud.order_params()
+        result_username = await dep(order_by="username", order="asc")
+        result_email = await dep(order_by="email", order="desc")
+        assert isinstance(result_username, ColumnElement)
+        assert isinstance(result_email, ColumnElement)
+
+    @pytest.mark.anyio
+    async def test_order_params_integrates_with_get_multi(
+        self, db_session: AsyncSession
+    ):
+        """order_params output is accepted by get_multi(order_by=...)."""
+        UserOrderCrud = CrudFactory(User, order_fields=[User.username])
+        await UserCrud.create(
+            db_session, UserCreate(username="charlie", email="c@test.com")
+        )
+        await UserCrud.create(
+            db_session, UserCreate(username="alice", email="a@test.com")
+        )
+
+        dep = UserOrderCrud.order_params()
+        order_by = await dep(order_by="username", order="asc")
+        results = await UserOrderCrud.get_multi(db_session, order_by=order_by)
+
+        assert results[0].username == "alice"
+        assert results[1].username == "charlie"

tests/test_example_pagination_search.py

@@ -15,12 +15,14 @@ from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_asyn
 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 .conftest import DATABASE_URL
 
 
 def build_app(session: AsyncSession) -> FastAPI:
     app = FastAPI()
+    init_exceptions_handlers(app)
 
     async def override_get_db():
         yield session
@@ -269,3 +271,125 @@ class TestCursorPagination:
         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"

tests/test_exceptions.py

@@ -8,6 +8,7 @@ from fastapi_toolsets.exceptions import (
     ApiException,
     ConflictError,
     ForbiddenError,
+    InvalidOrderFieldError,
     NotFoundError,
     UnauthorizedError,
     generate_error_responses,
@@ -334,3 +335,43 @@ class TestExceptionIntegration:
 
         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_message_contains_field_and_valid_fields(self):
+        """Exception message mentions the bad field and valid options."""
+        error = InvalidOrderFieldError("bad_field", ["name", "email"])
+        assert "bad_field" in str(error)
+        assert "name" in str(error)
+        assert "email" in str(error)
+
+    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"

tests/test_fixtures.py

@@ -14,7 +14,9 @@ from fastapi_toolsets.fixtures import (
     load_fixtures_by_context,
 )
 
-from .conftest import Role, User
+from fastapi_toolsets.fixtures.utils import _get_primary_key
+
+from .conftest import IntRole, Permission, Role, User
 
 
 class TestContext:
@@ -597,6 +599,46 @@ class TestLoadFixtures:
         count = await RoleCrud.count(db_session)
         assert count == 2
 
+    @pytest.mark.anyio
+    async def test_skip_existing_skips_if_record_exists(self, db_session: AsyncSession):
+        """SKIP_EXISTING returns empty loaded list when the record already exists."""
+        registry = FixtureRegistry()
+        role_id = uuid.uuid4()
+
+        @registry.register
+        def roles():
+            return [Role(id=role_id, name="admin")]
+
+        # First load — inserts the record.
+        result1 = await load_fixtures(
+            db_session, registry, "roles", strategy=LoadStrategy.SKIP_EXISTING
+        )
+        assert len(result1["roles"]) == 1
+
+        # Remove from identity map so session.get() queries the DB in the second load.
+        db_session.expunge_all()
+
+        # Second load — record exists in DB, nothing should be added.
+        result2 = await load_fixtures(
+            db_session, registry, "roles", strategy=LoadStrategy.SKIP_EXISTING
+        )
+        assert result2["roles"] == []
+
+    @pytest.mark.anyio
+    async def test_skip_existing_null_pk_inserts(self, db_session: AsyncSession):
+        """SKIP_EXISTING inserts when the instance has no PK set (auto-increment)."""
+        registry = FixtureRegistry()
+
+        @registry.register
+        def int_roles():
+            # No id provided — PK is None before INSERT (autoincrement).
+            return [IntRole(name="member")]
+
+        result = await load_fixtures(
+            db_session, registry, "int_roles", strategy=LoadStrategy.SKIP_EXISTING
+        )
+        assert len(result["int_roles"]) == 1
+
 
 class TestLoadFixturesByContext:
     """Tests for load_fixtures_by_context function."""
@@ -755,3 +797,19 @@ class TestGetObjByAttr:
         """Raises StopIteration when value type doesn't match."""
         with pytest.raises(StopIteration):
             get_obj_by_attr(self.roles, "id", "not-a-uuid")
+
+
+class TestGetPrimaryKey:
+    """Unit tests for the _get_primary_key helper (composite PK paths)."""
+
+    def test_composite_pk_all_set(self):
+        """Returns a tuple when all composite PK values are set."""
+        instance = Permission(subject="post", action="read")
+        pk = _get_primary_key(instance)
+        assert pk == ("post", "read")
+
+    def test_composite_pk_partial_none(self):
+        """Returns None when any composite PK value is None."""
+        instance = Permission(subject="post")  # action is None
+        pk = _get_primary_key(instance)
+        assert pk is None

uv.lock

@@ -251,7 +251,7 @@ wheels = [
 
 [[package]]
 name = "fastapi-toolsets"
-version = "1.2.1"
+version = "1.3.0"
 source = { editable = "." }
 dependencies = [
     { name = "asyncpg" },