add-backend-endpoint

name	Add Backend Endpoint
description	Checklist and guide for adding a new API endpoint to the FastAPI backend

Add Backend Endpoint Skill

Follow this checklist to add a new endpoint, ensuring all layers (Schema, Model, CRUD, Router) are covered.

Checklist

1. Define Pydantic Schemas (backend/app/schemas/)

Create or update a schema file. You need:

• BaseSchema: Common fields.
• CreateSchema: Fields required for creation.
• ResponseSchema: Fields returned to the client (include id, created_at).

2. Update Database Model (backend/app/models/)

If this endpoint involves new data, define the SQLAlchemy model.

• Action: Run database_migration skill if you modify models.

3. Service/CRUD Layer (backend/app/services/ or directly in Router)

For simple logic, you can put it in the router. for complex logic, create a service.

4. Create/Update Router (backend/app/routers/)

• Path Operations: Use @router.get, @router.post, etc.
• Response Model: Always specify response_model.
• Async: Use async def.
• DB Session: Inject dependencies: db: AsyncSession = Depends(get_db).

from fastapi import APIRouter, Depends
from sqlalchemy.ext.asyncio import AsyncSession
from app.database import get_db
from app.schemas.item import ItemResponse

router = APIRouter()

@router.get("/items", response_model=list[ItemResponse])
async def read_items(db: AsyncSession = Depends(get_db)):
    # ... logic
    return items

5. Register Router (backend/app/main.py)

If this is a new router file, include it in main.py:

from app.routers import new_router
app.include_router(new_router.router, prefix="/api/v1/resource", tags=["Resource"])