Bearer token handling in FastAPI - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the correct FastAPI security class for bearer token handling.

FastAPI

from fastapi.security import [1]

Drag options to blanks, or click blank then click option'

AHTTPBasic

BAPIKeyHeader

COAuth2PasswordBearer

DHTTPBearer

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing OAuth2PasswordBearer which is for OAuth2 flows, not simple bearer tokens.

Choosing HTTPBasic which is for basic auth, not bearer tokens.

The HTTPBearer class is used in FastAPI to handle bearer token authentication.

2fill in blank

medium

Complete the code to create an instance of the HTTPBearer security scheme.

FastAPI

security = [1]()

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AOAuth2PasswordBearer

BHTTPBearer

CHTTPBasic

DAPIKeyHeader

Attempts:

3 left

💡 Hint

Common Mistakes

Instantiating OAuth2PasswordBearer which requires a token URL.

Using HTTPBasic which is unrelated to bearer tokens.

Creating an instance of HTTPBearer allows FastAPI to extract bearer tokens from requests.

3fill in blank

hard

Fix the error in the dependency function to correctly extract the bearer token string.

FastAPI

async def get_token(credentials: HTTPAuthorizationCredentials = Depends(security)):
    return credentials.[1]

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Atoken

Btoken_type

Ccredentials

Daccess_token

Attempts:

3 left

💡 Hint

Common Mistakes

Using token_type which is usually 'Bearer', not the token itself.

Using access_token which is not an attribute of HTTPAuthorizationCredentials.

The HTTPAuthorizationCredentials object has a token attribute that contains the bearer token string.

4fill in blank

hard

Fill both blanks to define a FastAPI route that requires a bearer token and returns it.

FastAPI

from fastapi import FastAPI, Depends
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials

app = FastAPI()
security = HTTPBearer()

@app.get("/token")
async def read_token(credentials: [1] = Depends(security)):
    return {"token": credentials.[2]

Drag options to blanks, or click blank then click option'

AHTTPAuthorizationCredentials

BHTTPBearer

Ctoken

Dtoken_type

Attempts:

3 left

💡 Hint

Common Mistakes

Using HTTPBearer as the parameter type instead of HTTPAuthorizationCredentials.

Returning token_type instead of token.

The route depends on HTTPAuthorizationCredentials to get the credentials object, and returns the token attribute.

5fill in blank

hard

Fill all three blanks to create a dependency that validates the bearer token prefix and returns the token string.

FastAPI

from fastapi import HTTPException, status

async def verify_token(credentials: HTTPAuthorizationCredentials = Depends(security)):
    if credentials.scheme != [1]:
        raise HTTPException(status_code=[2], detail="Invalid authentication scheme")
    return credentials.[3]

Drag options to blanks, or click blank then click option'

A"Bearer"

Bstatus.HTTP_401_UNAUTHORIZED

Ctoken

D"Basic"

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for "Basic" scheme instead of "Bearer".

Using wrong status code like 403 instead of 401.

Returning scheme or token_type instead of token.

The scheme must be "Bearer" to accept bearer tokens. If not, raise 401 Unauthorized. Return the token string.