How Do You Debug An API Request Failing With a 500 Error Code?

When an API request fails with HTTP 500 (Internal Server Error), it means something went wrong on the server side — but as a tester/engineer, you can still approach debugging systematically. 1. Confirm the Failure Re-run the request to see if it’s consistent or intermittent. Try from multiple tools (Postman, curl, browser) to rule out client/tool issues. 2. Check the Request Endpoint URL → Is it correct? No typos? Correct HTTP method? Headers → Missing Content-Type, Authorization, or custom headers? Request Body → Validate JSON/XML format, required fields, and data types. Query/Path Params → Are they valid and within expected limits? 3. Review API Documentation Verify if the payload and parameters align with the latest API spec. Check for deprecated fields or new mandatory fields. 4. Check Server/Backend Logs (if you have access) Server logs often contain stack traces and root cause details. Look for null pointer errors, DB exceptions, or unhandled cases.