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Getting Started

Use Python 3.13 if you can (see Python 3.13 & compatibility); the minimum supported release is 3.10. Create a virtual environment before installing dependencies.

Install

pip install faster-api-web

Optional uvloop (recommended on Linux for lower event-loop overhead):

pip install faster-api-web[all]

For TestClient (integration tests), add httpx:

pip install faster-api-web[test]

For development (tests, linting, benchmarks):

pip install faster-api-web[dev]

Minimal application

Create main.py:

import msgspec
from FasterAPI import Faster

app = Faster()


class Item(msgspec.Struct):
    name: str
    price: float


@app.get("/items/{item_id}")
async def read_item(item_id: str):
    return {"item_id": item_id}


@app.post("/items")
async def create_item(item: Item):
    return {"received": item}

Run with Uvicorn

uvicorn main:app --reload

You should see:

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [...]
INFO:     Started server process [...]
INFO:     Waiting for application startup.
INFO:     Application startup complete.

Try it with curl

# GET request
curl http://127.0.0.1:8000/items/42
# {"item_id":"42"}

# POST request with JSON body
curl -X POST http://127.0.0.1:8000/items \
  -H "Content-Type: application/json" \
  -d '{"name":"Widget","price":9.99}'
# {"received":{"name":"Widget","price":9.99}}

Interactive API docs

Open http://127.0.0.1:8000/docs for the Swagger UI — automatically generated from your route definitions.

From the Swagger UI you can:

  • Browse all endpoints grouped by tags
  • Click Try it out on any route to send a live request
  • See the full request and response schema

Alternative docs are available at http://127.0.0.1:8000/redoc.

Imports at a glance

What you need Import
Application class from FasterAPI import Faster
Router (sub-router) from FasterAPI import FasterRouter
Request body helpers from FasterAPI import Body, Form, File
URL / query helpers from FasterAPI import Path, Query, Header, Cookie
Responses from FasterAPI import JSONResponse, HTMLResponse, FileResponse, …
Models import msgspec — use msgspec.Struct
DI from FasterAPI import Depends
Exceptions from FasterAPI import HTTPException
Middleware from FasterAPI import CORSMiddleware, GZipMiddleware, …
WebSocket from FasterAPI import WebSocket, WebSocketDisconnect
Background tasks from FasterAPI import BackgroundTasks
Testing from FasterAPI import TestClient 
myproject/
├── main.py          # app = Faster(), include_router calls
├── routers/
│   ├── items.py     # FasterRouter for items
│   └── users.py     # FasterRouter for users
├── models.py        # msgspec.Struct definitions
├── dependencies.py  # Shared Depends() callables
└── tests/
    ├── conftest.py
    └── test_items.py

Next steps