api-designlisted

# API Design ## Purpose Design REST/RPC endpoint contracts with request/response types, error handling, and versioning strategy. Produces TypeScript type definitions and endpoint documentation that serve as the contract between frontend and backend. ## Scope Constraints - Produces endpoint contracts and type definitions only; does not implement route handlers. - Covers endpoint specification, request/response types, error contracts, pagination, and caching. - Does not design database schemas or run codebase analysis — hand off to schema-design or codebase-context. ## Inputs - Feature requirements (from interview/idea phase) - Schema design output (entities, relationships — drives endpoint shape) - Existing endpoints (current route handlers, naming conventions) - Authentication/authorization model (who can call what) ## Input Sanitization No user-provided values are used in commands or file paths. All inputs are treated as read-only analysis targets. ## Procedure ### Progress Checklist <!-- Track completion across compaction boundaries --> - [ ] Step 1: Inventory Existing Endpoints - [ ] Step 2: Identify New Endpoints Needed - [ ] Step 3: Define Endpoint Contracts - [ ] Step 4: Design Type Definitions - [ ] Step 5: Plan Authentication/Authorization - [ ] Step 6: Define Error Contract - [ ] Step 7: Consider Pagination and Filtering - [ ] Step 8: Document Rate Limits and Caching ### Step 1: Inventory Existing Endpoints Read current route handlers and list all existin