Complete Course
API Testing Fundamentals
Understand APIs before you automate them: HTTP, REST, auth, schemas, and what is actually worth asserting, without tying yourself to a single tool.
~3 hours of content
Course Content
10 comprehensive lessons covering everything you need to know
Introduction
Introduction
Course Overview
Learn what this course covers, who it is for, and how it relates to the hands-on API testing courses.
Introduction
Why API testing pays off
Where API tests sit in the pyramid, why they are fast and stable, and what they cannot tell you.
How APIs work
Lesson
Lesson 1HTTP in practice
Methods, the status codes testers get wrong, the headers that matter, and why idempotency changes your retries.
Lesson
Lesson 2REST conventions and resource design
Resources, collections, nesting, and versioning, and how the conventions let you predict an undocumented endpoint.
Lesson
Lesson 3Request and response anatomy
Path and query parameters, bodies, content types, JSON structure, pagination, and reading a response critically.
Lesson
Lesson 4Authentication and authorization
API keys, Basic, Bearer and JWT, OAuth, token expiry, and keeping credentials out of your tests.
Designing API tests
Lesson
Lesson 5What to assert, and what not to
Status, schema, key values, and headers, plus the over-assertion trap that makes a suite break on every harmless change.
Lesson
Lesson 6Schema and contract validation
Validating shape instead of values, OpenAPI as a source of truth, and where contract testing starts.
Lesson
Lesson 7Test data and environment independence
Setup through the API itself, avoiding shared mutable fixtures, and why a test that passes only on Tuesdays is a data problem.
Lesson
Lesson 8Error cases and negative testing
Ten categories of bad input, boundaries, rate limits, timeouts, and the security-adjacent checks every tester should cover.
Working like a professional
Lesson
Lesson 9Exploring an API before testing it
Docs, OpenAPI, curl, and real traffic in DevTools, to build a mental model before writing anything.
Lesson
Lesson 10Running API tests in CI
What belongs in the pipeline, environments and secrets, keeping the suite fast, and failures people can act on.
Bonus & Conclusion
Bonus
Bonus: choosing your API testing tool
Every concept from the course mapped onto Postman, REST Assured, Playwright, Cypress, k6, and curl.
Conclusion
Congratulations!
You have completed the API Testing Fundamentals course!