MEPX
Chapter 10 of 10All chapters
  1. 1What an API is
  2. 2The request
  3. 3The response
  4. 4REST and its alternatives
  5. 5Authentication
  6. 6JSON and data shapes
  7. 7Pagination and filtering
  8. 8Rate limits and retries
  9. 9Versioning and change
  10. 10Calling and debugging APIs

Chapter 10 of 10

Calling and debugging APIs

Tools and habits.

Try it by hand

curl or an HTTP client sends a request without writing any code, which separates your bug from theirs. The browser network tab shows exactly what was sent and returned.

  • Check the status code first, then the headers, then the body.
  • A CORS error in the console is a browser rule, not a server failure.

When it is not your fault

Third party APIs go down, rate limit unexpectedly and change without warning. Log the request id they return, handle failure as a normal path, and cache what you can.