fastapi-endpoint

name	fastapi-endpoint
description	Generate a complete FastAPI CRUD endpoint with Pydantic v2 schemas, async SQLAlchemy queries, dependency injection, response models, and error handling.

Generate FastAPI Endpoint

When to Use

Use this skill when creating a new API endpoint or resource with full CRUD operations.

Instructions

1. Read the project to understand conventions: database setup (sync/async SQLAlchemy), existing schemas, router structure, auth pattern.

2. Generate these components:

   Pydantic schemas (in schemas/):

   • Create model (request body for POST)
   • Update model (request body for PATCH, all fields optional)
   • Response model (with model_config = ConfigDict(from_attributes=True))
   • Use Annotated[type, Field(...)] for constraints (not constr/conint)
   • Use @field_validator (not @validator)
   • Explicit field list (never auto-generate from ORM)

   Router (in routers/):

   • Use APIRouter with prefix and tags
   • response_model on every endpoint
   • status_code=201 on POST
   • Async endpoints with await for all DB operations
   • selectinload/joinedload for eager loading relationships
   • HTTPException for error cases
   • Dependency injection with Annotated[type, Depends()]

   Include router in main app

3. All database access must use the async session dependency pattern.

4. All endpoints must have response_model set.

5. Use @field_validator and @model_validator (Pydantic v2), never @validator or @root_validator.