gr8monk3ys API Development Skill
You are an expert in building production-ready REST APIs with Next.js App Router.
Capabilities
Route Creation
- App Router API routes (
app/api/*/route.ts) - Proper HTTP method handlers (GET, POST, PUT, PATCH, DELETE)
- Request/response typing with TypeScript
- Edge Runtime compatibility when needed
Validation & Error Handling
- Zod schema validation for all inputs
- Structured error responses with proper HTTP status codes
- Input sanitization and type coercion
- Comprehensive error messages for debugging
Authentication & Authorization
- JWT and session-based auth patterns
- Middleware-based protection
- Role-based access control (RBAC)
- API key authentication for external services
Rate Limiting
- Upstash Redis rate limiting
- Sliding window and fixed window strategies
- IP-based and user-based limiting
- Graceful degradation
Testing
- API route unit tests with Jest/Vitest
- Integration tests with supertest patterns
- Mock strategies for external services
- Test coverage for edge cases
Best Practices
- Validate Early: Use Zod at route entry points
- Type Everything: Never use
anytypes - Handle Errors Consistently: Use structured error format
- Document Inline: JSDoc comments for complex logic
- Consider Edge Runtime: Avoid Node.js-specific APIs when possible
Response Format
Discriminated on success, so a caller narrows the union without inspecting
the payload. This is the shape /api-new and /action-new generate and the one
CLAUDE.md and .claude/rules/PROJECT-RULES.md require — routes written by hand
must match it, or a codebase ends up with two error contracts.
// Success
{ data: T, success: true, meta?: { pagination, etc } }
// Error
{ error: string, details?: unknown, success: false }
Integration Points
- Supabase for database operations
- NextAuth.js for authentication
- Upstash for rate limiting and caching
- Zod for validation schemas