API key authentication in FastAPI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is API key authentication?

API key authentication is a simple way to control access to an API by requiring a unique key from the client with each request. It acts like a secret password to identify and allow the user.

beginner

How do you pass an API key in a FastAPI request?

You can pass the API key in the request header, usually with a custom header like X-API-Key, or as a query parameter. FastAPI can read these values to check the key.

intermediate

What FastAPI feature helps to check API keys easily?

FastAPI's Depends function allows you to create reusable security checks, like verifying an API key before running the main code of an endpoint.

beginner

Why should API keys be kept secret and not shared publicly?

API keys grant access to your API. If someone else gets your key, they can use your API without permission, which can cause data leaks or extra costs.

beginner

What is a common way to respond if an API key is missing or invalid in FastAPI?

You return an HTTP 401 Unauthorized error with a message like 'Invalid or missing API key' to tell the client they need to provide a valid key.

In FastAPI, which method is commonly used to enforce API key authentication?

A Using class-based views

B Using global variables

C Using print statements

D Using Depends to check the API key

FastAPI uses Depends to create reusable security checks like API key verification.

Where is an API key usually sent in an HTTP request?

A In the HTML title tag

B In the response body

C In the request header

D In the server logs

API keys are typically sent in request headers or query parameters, not in responses or HTML.

What HTTP status code should you return if the API key is missing or invalid?

A 401 Unauthorized

B 200 OK

C 404 Not Found

D 500 Internal Server Error

401 Unauthorized tells the client they need to provide valid authentication credentials.

Why is it important to keep API keys secret?

A Because they allow access to your API

B Because they improve website speed

C Because they change the UI colors

D Because they store user passwords

API keys control access to your API and should be kept secret to prevent misuse.

Which FastAPI feature helps you reuse code for checking API keys across endpoints?

A Templates

B Depends

C Middleware

D Static files

Depends allows you to create reusable dependencies like API key checks.

Explain how you would implement API key authentication in a FastAPI app.

Think about how FastAPI handles dependencies and errors.

Why is API key authentication useful and what are its limitations?

Consider both benefits and security concerns.