OAuth and API Authentication: Accessing Secure APIs
Explains the three main API authentication patterns, API keys (query param and header variants), HTTP Basic Auth, and OAuth 2.0, with Python code for each. Walks through the full OAuth 2.0 authorization code flow using GitHub as the example: redirect the user to an authorization URL, receive the auth code, exchange it for an access token, and call the protected API. Also covers OAuth 1.0a versus 2.0 differences and shows how to use a refresh token to silently renew expired access tokens without re-prompting the user.