phase-4-api_skill

Overview

This skill helps design and implement backend RESTful APIs and validate them using a Zero Script QA methodology. It focuses on practical endpoint design, clean request/response contracts, implementation structure, and log-driven verification instead of formal test scripts. Use it proactively when you need reliable, production-ready backend APIs.

How this skill works

I guide you through defining resource-based endpoints, HTTP methods, status codes, and consistent response formats. I provide an implementation layout (routes, controllers, services) and prescribe Zero Script QA: structured runtime logs that document inputs, processing steps, outputs, and results for validation. The skill also includes PDCA guidance to plan, build, check with logs, and iterate.

When to use it

• Designing a new REST API for a backend service
• Implementing CRUD endpoints with clear contracts
• Validating API behavior quickly without writing test scripts
• Migrating or versioning existing APIs (v1, v2)
• Preparing backend APIs for integration with frontends or BaaS alternatives

Best practices

• Use resource-based, plural URLs and proper HTTP verbs (GET, POST, PUT, PATCH, DELETE).
• Return consistent success and error payloads with meta and pagination where applicable.
• Include status codes: 200/201/204 for success, 4xx for client errors, 5xx for server errors.
• Log structured steps for Zero Script QA: [INPUT], [PROCESS] entries, [OUTPUT], [RESULT].
• Version APIs via URL or headers and document contracts with OpenAPI/Swagger.

Example use cases

• Create a /users API with endpoints for list, retrieve, create, update, delete and structured responses with pagination.
• Implement order management endpoints (/orders) with clear status transitions and idempotent updates where applicable.
• Use Zero Script QA during bug triage: reproduce a request, inspect structured logs showing each processing step, and fix the failing stage.
• Design a public v1 API for a service and prepare a v2 migration plan with backward-compatible routes and header versioning.