from fastapi import Depends, FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


async def user_exists(user_id: int):
    return True


@app.get("/users/{user_id}", dependencies=[Depends(user_exists)])
async def read_users(user_id: int):
    pass


client = TestClient(app)


def test_read_users():
    response = client.get("/users/42")
    assert response.status_code == 200, response.text

from fastapi import Depends, FastAPI, Security
from fastapi.security import APIKeyHeader
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyHeader(name="key")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user


@app.get("/users/me")

from fastapi import Depends, FastAPI, Security
from fastapi.security import APIKeyHeader
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()

api_key = APIKeyHeader(name="key", description="An API Key Header")


class User(BaseModel):
    username: str


def get_current_user(oauth_header: str = Security(api_key)):
    user = User(username=oauth_header)
    return user

/// info | Technical Details

`Security` is actually a subclass of `Depends`, and it has just one extra parameter that we'll see later.

But by using `Security` instead of `Depends`, **FastAPI** will know that it can declare security scopes, use them internally, and document the API with OpenAPI.

But when you import `Query`, `Path`, `Depends`, `Security` and others from `fastapi`, those are actually functions that return special classes.

                sb.append("'>");
                sb.append(option.getLongOpt());
                sb.append("</a>");
            }

            if (option.hasArg()) {
                if (option.hasArgName()) {
                    sb.append(" &lt;").append(option.getArgName()).append("&gt;");
                } else {
                    sb.append(' ');
                }
            }
            sb.append("</code>");

        sb.append(dm).append(includedPaths);
        sb.append(dm).append(intervalTime);
        sb.append(dm).append(maxAccessCount);
        sb.append(dm).append(name);
        sb.append(dm).append(numOfThread);
        sb.append(dm).append(paths);
        sb.append(dm).append(permissions);
        sb.append(dm).append(sortOrder);
        sb.append(dm).append(timeToLive);
        sb.append(dm).append(updatedBy);

        sb.append(dm).append(includedUrls);
        sb.append(dm).append(intervalTime);
        sb.append(dm).append(maxAccessCount);
        sb.append(dm).append(name);
        sb.append(dm).append(numOfThread);
        sb.append(dm).append(permissions);
        sb.append(dm).append(sortOrder);
        sb.append(dm).append(timeToLive);
        sb.append(dm).append(updatedBy);
        sb.append(dm).append(updatedTime);

		return
	}
	// string "Endpoint"
	o = append(o, 0xa8, 0x45, 0x6e, 0x64, 0x70, 0x6f, 0x69, 0x6e, 0x74)
	o = msgp.AppendString(o, z.Endpoint)
	// string "Path"
	o = append(o, 0xa4, 0x50, 0x61, 0x74, 0x68)
	o = msgp.AppendString(o, z.Path)
	// string "Creds"
	o = append(o, 0xa5, 0x43, 0x72, 0x65, 0x64, 0x73)
	// map header, size 3
	// string "AccessKey"

        StringBuilder sb = new StringBuilder(256);
        sb.append("[scope=").append(scope.getScope());
        if (classpath != null) {
            for (ArtifactMetadata md : classpath) {
                sb.append(": ")
                        .append(md.toString())
                        .append('{')
                        .append(md.getArtifactUri())
                        .append('}');
            }
        }

        StringBuilder sb = new StringBuilder(128);
        sb.append(artifact.getArtifactId());
        sb.append('-').append(artifact.getBaseVersion());
        if (artifact.getClassifier() != null) {
            sb.append('-').append(artifact.getClassifier());
        }
        sb.append('.').append(artifact.getType()).append(LAST_UPDATE_TAG);
        return new File(artifact.getFile().getParentFile(), sb.toString());