Api Contract Guardian For Ai Coding Agents

Protects API endpoints from accidental breaking changes by generating contract maps, validation rules, integration tests, documentation, and safe AI coding prompts.

Install
cmdop skills install agensi-api-contract-guardian-for-ai-coding-agents

API Contract Guardian is a skill for AI coding agents, backend and frontend engineers, QA teams, integration teams, SaaS builders, and API maintainers who need to protect API behavior before creating, modifying, documenting, or testing endpoints. It converts vague API change requests into structured artifacts: contract maps that capture the shape and intent of an endpoint, consumer dependency reviews that surface which clients rely on existing behavior, and breaking-change risk audits that flag what a modification would affect. From there it produces request validation plans, response schema plans, error format standards, and contract test strategies so teams know exactly what to verify before shipping. For documentation needs it generates OpenAPI-style documentation outlines and webhook verification plans. For teams managing API lifecycles it produces versioning plans and migration notes. All outputs can be formatted as paste-ready prompts for AI coding environments including Cursor, Claude Code, Codex CLI, OpenCode, Replit, and ChatGPT Agents, making it straightforward to feed the analysis directly into whichever tool is writing the code. The skill is particularly suited to preventing frontend-backend drift, protecting mobile app and SDK consumers from unexpected contract changes, documenting endpoints that currently have no formal spec, testing REST APIs, and reviewing GraphQL schema changes before they reach production. It does not execute code, run live tests, or connect to a database.

Use cases

  • Generate a breaking-change risk audit before modifying a production REST endpoint
  • Produce an OpenAPI-style documentation outline for an undocumented internal API
  • Create a contract test strategy to protect mobile SDK consumers from schema drift
  • Build a versioning plan and migration notes when deprecating an API field
  • Generate paste-ready prompts for Cursor or Claude Code that encode endpoint contracts
  • Review a proposed GraphQL schema change for downstream consumer impact

When to use it

  • When an AI coding agent is about to modify an endpoint and the impact on consumers is unclear
  • When frontend and backend teams are diverging on expected request or response shapes
  • When an undocumented endpoint needs a formal contract before further development
  • When a QA or integration team needs a contract test strategy for a REST or GraphQL API
  • When a versioning or migration plan is needed before deprecating API fields

When not to use it

  • When live API execution, actual HTTP requests, or real test runs are required — this skill produces plans and documents, not running code
  • When the project uses a non-REST, non-GraphQL protocol such as gRPC or WebSocket-only interfaces
  • When automated CI pipeline integration is needed, as the skill generates prompts and documents rather than runnable test files
  • When a database schema tool is needed rather than an API contract tool