RoyceFastAPI: Python's Fastest Growing Framework FastAPI is now the third most popular Python...
FastAPI is now the third most popular Python web framework after Django and Flask, with downloads growing 40% year-over-year in 2025. For SaaS, its automatic OpenAPI documentation, async-first design, and type hints that generate validation make it uniquely powerful for AI/ML-backed applications.
In 2026, FastAPI's position as the default Python framework for AI services is locked in.
| Starter | Price | Auth | DB | Frontend | AI/ML | Best For |
|---|---|---|---|---|---|---|
| full-stack-fastapi-template | Free | Full | PostgreSQL | React | ❌ | Production full-stack |
| fastapi-best-practices | Free | ❌ | ❌ | ❌ | ❌ | Architecture guide |
| fastapi-users | Free | Auth only | Multiple | ❌ | ❌ | Auth library |
| fastapi-postgres | Free | JWT | PostgreSQL | ❌ | ❌ | Backend API |
| AuthX | Free | Full auth | Multiple | ❌ | ❌ | Auth + JWT |
Price: Free (MIT) | Creator: FastAPI team (Sebastián Ramírez)
The official FastAPI full-stack template. FastAPI backend, React + TypeScript + Vite frontend, PostgreSQL, SQLModel ORM, JWT auth, Docker Compose, Traefik proxy, email signup, and admin user management. Production-ready with GitHub Actions CI.
├── backend/
│ ├── app/
│ │ ├── api/ # Route handlers
│ │ ├── core/ # Config, security
│ │ ├── crud/ # Database operations
│ │ ├── models/ # SQLModel models
│ │ └── tests/ # pytest tests
├── frontend/
│ ├── src/
│ │ ├── components/ # React components
│ │ ├── routes/ # TanStack Router
│ │ └── client/ # Auto-generated API client
└── docker-compose.yml
Choose if: You want the official, maintained FastAPI full-stack starter.
Price: Free | Creator: François Voron
The standard Python library for FastAPI authentication. Not a complete boilerplate — a configurable auth system that handles registration, login, email verification, password reset, OAuth2, and JWT. Drop it into any FastAPI project.
from fastapi_users import FastAPIUsers
from fastapi_users.authentication import JWTStrategy, BearerTransport
def get_jwt_strategy() -> JWTStrategy:
return JWTStrategy(secret=SECRET, lifetime_seconds=3600)
fastapi_users = FastAPIUsers[User, uuid.UUID](
get_user_manager,
[auth_backend],
)
app.include_router(fastapi_users.get_auth_router(auth_backend))
app.include_router(fastapi_users.get_register_router(UserRead, UserCreate))
app.include_router(fastapi_users.get_verify_router(UserRead))
Choose if: You're building on top of a custom FastAPI project and need auth.
Price: Free | Creator: Community
FastAPI + PostgreSQL + SQLAlchemy async + Alembic migrations + JWT auth + pytest. Clean project structure without a frontend. The standard Python API backend template.
Choose if: You're building a pure API backend, not a full-stack app.
FastAPI generates interactive OpenAPI documentation from type hints:
from fastapi import FastAPI
from pydantic import BaseModel
app = FastAPI()
class Item(BaseModel):
name: str
price: float
is_offer: bool = None
@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
return {"item_name": item.name, "item_id": item_id}
This automatically creates /docs (Swagger UI) and /redoc — no manual API documentation needed.
FastAPI's async-first design enables high concurrency without threads:
from fastapi import FastAPI
app = FastAPI()
@app.get("/slow-endpoint")
async def slow_endpoint():
await asyncio.sleep(5) # Non-blocking — other requests served during wait
return {"message": "done"}
FastAPI's Python runtime makes AI/ML features trivial:
from fastapi import FastAPI
from transformers import pipeline # HuggingFace, no microservice needed
app = FastAPI()
classifier = pipeline("text-classification")
@app.post("/classify")
async def classify_text(text: str):
return classifier(text)[0] # Direct model call in your API
Choose FastAPI when:
Choose Express/Node.js when:
Compare all FastAPI boilerplates on StarterPick — find the right Python API starter.