Hoeseong (Hayden) Kim, Hugo Mano, Hyeontaek Lim, Ibrahim Umit Akgun, ILCSFNO, Ilia Sergachev, Ilya Tikhonovskiy, Iman Hosseini, Ionel Gog, Isha Arkatkar, isharif168, Ivo Ristovski List, Jacques Pienaar, Jae H. Yoo, Jaeyoon Jung, Jake Harmon, James Hilliard, jameslovespancakes, James Spooner, Jane Liu, Jaroslav Sevcik, Jeff Parker, Jeffrey A. Dean, Jeremy Meredith, Jialei Chen, Jian Cai, Jian Li, Jie Luo, Jim Lin, Jing Pu, Jinliang Wei, Jiya Zhang, Joel Wee, Johannes Buchner, Johannes Reifferscheid,...

from fastapi import Depends, FastAPI, Header, HTTPException


async def verify_token(x_token: str = Header()):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def verify_key(x_key: str = Header()):
    if x_key != "fake-super-secret-key":
        raise HTTPException(status_code=400, detail="X-Key header invalid")
    return x_key

from fastapi import FastAPI, Response

app = FastAPI()


@app.post("/cookie-and-object/")
def create_cookie(response: Response):
    response.set_cookie(key="fakesession", value="fake-cookie-session-value")

from typing import Annotated

from fastapi import Header, HTTPException


async def get_token_header(x_token: Annotated[str, Header()]):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def get_query_token(token: str):
    if token != "jessica":

### Create a dependency, or "dependable" { #create-a-dependency-or-dependable }

Let's first focus on the dependency.

It is just a function that can take all the same parameters that a *path operation function* can take:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8:9] *}

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

          @Override
          String toPendingString() {

            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

          @Override
          String toPendingString() {

# FastAPI Cloud { #fastapi-cloud }

You can deploy your FastAPI app to [FastAPI Cloud](https://fastapicloud.com) with **one command**, go and join the waiting list if you haven't. 🚀

## Login { #login }

Make sure you already have a **FastAPI Cloud** account (we invited you from the waiting list 😉).

Then log in:

<div class="termy">

```console
$ fastapi login

You are logged in to FastAPI Cloud 🚀
```

</div>

But `OAuth2PasswordRequestForm` is just a class dependency that you could have written yourself, or you could have declared `Form` parameters directly.

But as it's a common use case, it is provided by **FastAPI** directly, just to make it easier.

///

### Use the form data { #use-the-form-data }

/// tip

    MoreFiles.touch(temp);
    assertThat(Files.getLastModifiedTime(temp).toMillis()).isNotEqualTo(0);
  }

  public void testCreateParentDirectories_root() throws IOException {
    // We use a fake filesystem to sidestep flaky problems with Windows (b/136041958).
    try (FileSystem fs = Jimfs.newFileSystem(Configuration.unix())) {
      Path root = fs.getRootDirectories().iterator().next();