API Testing Basics: Your First Test Patterns
API testing basics for beginners: negative testing, retries and timeouts, and validation errors, the first test categories that catch real bugs.
Track 4 of 9 in API 101, our free API testing course for beginners.
- For Manual testers
- For Automation engineers
API Negative Testing: Breaking Your API Before Attackers Do
Happy paths prove your API works. Negative paths prove it fails safely. Here are the seven categories, a worked example, and where AI generation helps.
Retries and Timeouts: Testing APIs That Live on Unreliable Networks
The network is unreliable. Here's how clients should retry, how servers should behave, and how to test both.
Testing Validation Errors: The Most Neglected Test Category
Most API bugs live in input validation. Here's how to test it systematically.
Practice these lessons on your own APIs.
The Free Developer License of Shift-Left API is a single-user license that renews free every 6 months. Import your OpenAPI spec, generate tests, mock APIs and run workflows on your own machine. Want the full guides first? Browse the API testing hub.