Skill Claude CodeCodex
Method for assessing a codebase's structure — duplication, single-responsibility violations, layering problems, and coupling — and recommending minimal, incremental improvements. Use when asked to review architecture, assess structure or technical debt, evaluate module boundaries, or plan a refactor. Reviews the…
Skill Claude CodeCodex
Regression-first workflow for fixing a defect whose cause is known. Reproduce the confirmed defect, fix the root cause minimally, protect it with a regression test, and verify. If the root cause is still unknown, use the debugging skill first.
Skill Claude CodeCodex
Checklist and method for reviewing code quality — readability, maintainability, SOLID, DRY, performance, and backward compatibility. Use when asked to review code, a diff, a branch, or a merge request for quality, or before finalizing significant changes. For GitHub PR review use the built-in /review; for…
Skill Claude CodeCodex
Investigate failures whose root cause is still unknown — narrow the search space, instrument, and test falsifiable hypotheses. Use for intermittent or environment-dependent behavior, unexplained stack traces, regressions with no known trigger, or any symptom without a confirmed cause. Ends once the root cause is…
Skill Claude CodeCodex
Security review and hardening workflow — root-cause analysis of vulnerabilities, authentication and authorization checks, least privilege, input handling, secret hygiene, and security regression tests. Use when reviewing code for security, fixing a vulnerability, hardening a feature, or handling auth, permissions…
Skill Claude CodeCodex
Strategy and rules for writing or improving automated tests. Use when adding tests, improving coverage, fixing flaky tests, setting up a test suite, or deciding what and how to test. Emphasizes deterministic tests, testing behavior over implementation, and a tight validation loop. For diagnosing production failures…