Java fuzz testing with CATS

Design and implement contract-driven fuzz testing for Java APIs using CATS to uncover edge cases and input-validation defects early.

What is covered in this Skill?

• CATS setup and baseline command usage for OpenAPI-driven fuzzing
• Negative testing strategy for invalid payloads, missing fields, wrong types, and malformed values
• Boundary testing for size, range, format, and enum constraints
• CI integration patterns with actionable logs and reproducible failures
• Local execution workflow for contributors before opening pull requests
• Reporting and triage practices for fuzzing findings

Scope: Focus on HTTP API fuzzing and contract validation with CATS. Use this skill to define practical, repeatable checks in both local and CI workflows.

Constraints

Before applying any fuzz testing changes, ensure the project compiles. If compilation fails, stop immediately. After implementation, regenerate skills and run verification.