API Contract Checker

SkillDev tools

Validate API changes against an expected contract. Use when a mid-level developer needs to detect breaking changes.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the API Contract Checker skill

What this skill tells your AI

The instructions your AI receives, as published by proflead/codex-skills-library in skills/api/api-contract-checker/SKILL.md and read by ahel’s review.

Purpose

Validate API changes against an expected contract.

Inputs to request

  • Old and new API specs or examples.
  • Versioning policy and client expectations.
  • Known consumers and usage patterns.

Workflow

  1. Compare endpoints, request/response fields, and status codes.
  2. Identify breaking changes and backward-compatible adjustments.
  3. Suggest versioning or migration notes.

Output

  • Breaking change report with mitigation steps.

Quality bar

  • Flag any removal or behavior change clearly.
  • Recommend safe rollouts for clients.

Signals

GitHub stars
144
Forks
30
Last commit
Jul 2026
Advanced
Catalog kind
skill
Gateway key
api-contract-checker
Source
github.com/proflead/codex-skills-library