user_dict = db[username]
        return UserInDB(**user_dict)


def fake_decode_token(token):
    # This doesn't provide any security at all
    # Check the next version
    user = get_user(fake_users_db, token)
    return user


async def get_current_user(token: Annotated[str, Depends(oauth2_scheme)]):
    user = fake_decode_token(token)
    if not user:
        raise HTTPException(

def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user

def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user

    response = client.get(
        "/items/", headers={"X-Token": "fake-super-secret-token", "X-Key": "invalid"}
    )
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "X-Key header invalid"}


def test_get_invalid_second_header_users():
    response = client.get(
        "/users/", headers={"X-Token": "fake-super-secret-token", "X-Key": "invalid"}
    )

        "/items?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200
    assert response.json() == {
        "plumbus": {"name": "Plumbus"},
        "gun": {"name": "Portal Gun"},
    }


def test_items_with_no_token_jessica(client: TestClient):
    response = client.get("/items", headers={"X-Token": "fake-super-secret-token"})
    assert response.status_code == 422

        "/items?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 200
    assert response.json() == {
        "plumbus": {"name": "Plumbus"},
        "gun": {"name": "Portal Gun"},
    }


@needs_py39
def test_items_with_no_token_jessica(client: TestClient):
    response = client.get("/items", headers={"X-Token": "fake-super-secret-token"})

from dirty_equals import IsDict, IsOneOf
from fastapi.testclient import TestClient

from docs_src.security.tutorial005_an import (
    app,
    create_access_token,
    fake_users_db,
    get_password_hash,
    verify_password,
)

client = TestClient(app)


def get_access_token(username="johndoe", password="secret", scope=None):
    data = {"username": username, "password": password}
    if scope:
        data["scope"] = scope

These examples run the server program (e.g Uvicorn), starting **a single process**, listening on all the IPs (`0.0.0.0`) on a predefined port (e.g. `80`).

This is the basic idea. But you will probably want to take care of some additional things, like:

* Security - HTTPS
* Running on startup
* Restarts
* Replication (the number of processes running)
* Memory
* Previous steps before starting

    ```

So, **FastAPI** will take care of filtering out all the data that is not declared in the output model (using Pydantic).

### `response_model` or Return Type

In this case, because the two models are different, if we annotated the function return type as `UserOut`, the editor and tools would complain that we are returning an invalid type, as those are different classes.

def get_user(db, username: str):
    if username in db:
        user_dict = db[username]
        return UserInDB(**user_dict)


def authenticate_user(fake_db, username: str, password: str):
    user = get_user(fake_db, username)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user