What problem does it solve? Designing web APIs without clear conventions leads to inconsistent endpoints, breaking changes, and fragile error handling that frustrates API consumers. This Skill provides contract-first design rules for REST and GraphQL APIs so endpoints are predictable, evolvable, and backward compatible. ## Core Features & Use Cases - Contract-First API Design: Draft OpenAPI specifications for REST or schema definitions for GraphQL that match the project's existing framework (FastAPI, Express, Next.js, Django). - Standardized Error Handling: Apply RFC 7807 problem details with stable machine-readable fields instead of ad-hoc error strings. - Scalable Pagination & Filtering: Define cursor-based pagination with explicit filter and sort parameters for high-volume list endpoints. - Use Case: When adding a paginated orders endpoint to an existing FastAPI service, use this Skill to produce the OpenAPI contract, RFC 7807 error envelope, and cursor pagination parameters without changing the stack. ## Quick Start Ask the agent to design a paginated REST endpoint with an OpenAPI contract and standardized RFC 7807 error responses for the current project.
