14. Auth - API Keys

In this final part, you will look at API keys as a simple mechanism for machine-to-machine authentication, and you will review the authentication methods covered in the session.

1. API keys: concept

• API keys are usually long, random strings given to other services or scripts.
• The client includes the key with each request (for example in an x-api-key header).
• The server validates the key and decides whether to allow the request.
• API keys are convenient for machines, but not ideal as the only method of authenticating human users.

2. Adding an API-key-protected route (Snippets API)

As an example, you can:

• Introduce an environment variable like API_KEY.
• Create a middleware (e.g. requireApiKey) that:

  • Reads the x-api-key header.
  • Compares it with the configured key.
  • Returns 401 if it is missing or incorrect.
• Use this middleware on a “machine-style” endpoint, such as:

  • A /metrics or /health endpoint.
  • A bulk export route for snippets data.

3. Optional rate limiting idea

To prevent abuse, you can sketch (or implement) a very simple rate limiting strategy:

• Use an in-memory object to count requests per API key.
• Deny further requests after a certain number within a short time window.
• Discuss why a production-grade solution would need shared storage and more robust logic.