Bearer token authentication in Rest API - Mini Project: Build & Apply

Bearer Token Authentication

📖 Scenario: You are building a simple REST API that requires users to authenticate using a bearer token. This is a common way to secure APIs by sending a secret token with each request.

🎯 Goal: Create a REST API endpoint that checks for a bearer token in the request headers and returns a success message if the token is valid, or an error message if it is missing or invalid.

📋 What You'll Learn

Create a variable called VALID_TOKEN with the exact value 'abc123token'.

Create a function called check_token that takes a headers dictionary as input.

In check_token, check if the Authorization header exists and starts with 'Bearer '.

Extract the token from the Authorization header and compare it to VALID_TOKEN.

Return True if the token matches, otherwise False.

Create a function called api_endpoint that takes a headers dictionary as input.

Use check_token inside api_endpoint to verify the token.

Return the string 'Access granted' if the token is valid, or 'Access denied' if not.

Print the result of calling api_endpoint with the headers {'Authorization': 'Bearer abc123token'}.

💡 Why This Matters

🌍 Real World

Bearer token authentication is widely used to secure APIs in web and mobile apps. It helps ensure that only authorized users can access protected resources.

💼 Career

Understanding bearer token authentication is essential for backend developers, API developers, and anyone working with secure web services.

1

Create the valid token variable

Create a variable called VALID_TOKEN and set it to the string 'abc123token'.

Rest API

# Create the valid token variable
# Your code here

Need a hint?

Think of VALID_TOKEN as the secret key that the API will accept.

2

Create the token check function

Create a function called check_token that takes a parameter headers. Inside the function, check if the Authorization header exists in headers and starts with 'Bearer '. Return True if the token after 'Bearer ' matches VALID_TOKEN, otherwise return False.

Rest API

VALID_TOKEN = 'abc123token'

def check_token(headers):
    # Your code here

Need a hint?

Use headers.get('Authorization', '') to safely get the header. Then check if it starts with 'Bearer '. Extract the token by slicing the string after 'Bearer '.

3

Create the API endpoint function

Create a function called api_endpoint that takes a parameter headers. Inside the function, use check_token(headers) to verify the token. Return the string 'Access granted' if the token is valid, otherwise return 'Access denied'.

Rest API

VALID_TOKEN = 'abc123token'

def check_token(headers):
    auth = headers.get('Authorization', '')
    if auth.startswith('Bearer '):
        token = auth[len('Bearer '):]
        return token == VALID_TOKEN
    return False

def api_endpoint(headers):
    # Your code here

Need a hint?

Use an if statement to check the result of check_token(headers). Return the correct string based on the result.

4

Print the API endpoint result

Print the result of calling api_endpoint with the headers dictionary {'Authorization': 'Bearer abc123token'}.

Rest API

VALID_TOKEN = 'abc123token'

def check_token(headers):
    auth = headers.get('Authorization', '')
    if auth.startswith('Bearer '):
        token = auth[len('Bearer '):]
        return token == VALID_TOKEN
    return False

def api_endpoint(headers):
    if check_token(headers):
        return 'Access granted'
    else:
        return 'Access denied'

print(api_endpoint({'Authorization': 'Bearer abc123token'}))  # Your code here

Need a hint?

Use print() to show the result of api_endpoint called with the correct headers.