Lesson 23 / 24

Testing APIs

Exercising endpoints by hand and in automated suites.

Postman for exploration

Postman (or Insomnia) lets you build requests visually, save them into collections, chain requests together, and share a documented workspace with a team — great for manual and exploratory testing.

curl for scripting

A one-liner that's copy-pasteable into any shell, CI job, or bug report.

curl -X POST https://api.example.com/v1/orders \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"productId": 42, "qty": 2}'

Automate contract tests

Beyond manual checks, run automated tests that assert status codes and response shapes against every endpoint on every deploy — catch breaking changes before clients do.