/// note | `async` Technical Details

When you use the `async` methods, **FastAPI** runs the file methods in a threadpool and awaits for them.

///

/// note | Starlette Technical Details

**FastAPI**'s `UploadFile` inherits directly from **Starlette**'s `UploadFile`, but adds some necessary parts to make it compatible with **Pydantic** and the other parts of FastAPI.

///

## What is "Form Data" { #what-is-form-data }

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str = Query(min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

---

For example, in Visual Studio Code, you can:

* Go to the "Debug" panel.
* "Add configuration...".
* Select "Python"
* Run the debugger with the option "`Python: Current File (Integrated Terminal)`".

It will then start the server with your **FastAPI** code, stop at your breakpoints, etc.

Here's how it might look:

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(
    hidden_query: str | None = Query(default=None, include_in_schema=False),
):
    if hidden_query:
        return {"hidden_query": hidden_query}
    else:

name: FastAPI People Contributors

on:
  schedule:
    - cron: "0 3 1 * *"
  workflow_dispatch:
    inputs:
      debug_enabled:
        description: "Run the build with tmate debugging enabled (https://github.com/marketplace/actions/debugging-with-tmate)"
        required: false
        default: "false"

jobs:
  job:
    if: github.repository_owner == 'fastapi'
    runs-on: ubuntu-latest
    permissions:
      contents: write

name: FastAPI People Sponsors

on:
  schedule:
    - cron: "0 6 1 * *"
  workflow_dispatch:
    inputs:
      debug_enabled:
        description: "Run the build with tmate debugging enabled (https://github.com/marketplace/actions/debugging-with-tmate)"
        required: false
        default: "false"

jobs:
  job:
    if: github.repository_owner == 'fastapi'
    runs-on: ubuntu-latest
    permissions:
      contents: write

from base64 import b64encode

from fastapi import FastAPI, Security
from fastapi.security import HTTPBasic, HTTPBasicCredentials
from fastapi.testclient import TestClient
from inline_snapshot import snapshot

app = FastAPI()

security = HTTPBasic(realm="simple")


@app.get("/users/me")
def read_current_user(credentials: HTTPBasicCredentials = Security(security)):
    return {"username": credentials.username, "password": credentials.password}

from fastapi import FastAPI, File, Form, UploadFile

app = FastAPI()


@app.post("/files/")
async def create_file(
    file: bytes = File(), fileb: UploadFile = File(), token: str = Form()
):
    return {
        "file_size": len(file),
        "token": token,
        "fileb_content_type": fileb.content_type,

from collections.abc import Callable
from typing import Annotated

from fastapi import Body, FastAPI, HTTPException, Request, Response
from fastapi.exceptions import RequestValidationError
from fastapi.routing import APIRoute


class ValidationErrorLoggingRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

        async def custom_route_handler(request: Request) -> Response:

import pytest
from fastapi import APIRouter, FastAPI
from fastapi.exceptions import FastAPIError
from fastapi.testclient import TestClient

app = FastAPI()

router = APIRouter()


@router.get("")
def get_empty():
    return ["OK"]


app.include_router(router, prefix="/prefix")


client = TestClient(app)


def test_use_empty():
    with client:
        response = client.get("/prefix")