API Builder
CautionScaffold REST and GraphQL APIs with route generation, validation, authentication middleware, and OpenAPI documentation.
$ claude install api-builder About This Skill
Overview
API Builder accelerates backend development by generating production-ready API endpoints from high-level descriptions. Whether you need a REST API with Express or a GraphQL server with Apollo, this skill handles the boilerplate while you focus on business logic.
Key Features
- Route Scaffolding: Describe your resources and relationships, and the skill generates CRUD endpoints with proper HTTP methods, status codes, and response formats.
- Input Validation: Every endpoint includes request validation using Zod or Joi schemas, with meaningful error messages for invalid inputs.
- Auth Middleware: Generates JWT or session-based authentication middleware with role-based access control out of the box.
- OpenAPI Generation: Automatically produces OpenAPI 3.1 documentation that stays in sync with your code, including request/response examples.
Supported Frameworks
Express.js, Fastify, Hono, and Koa for REST APIs. Apollo Server and Yoga for GraphQL. Python support includes FastAPI and Flask. Each framework follows its idiomatic patterns and best practices.
Architecture Patterns
The skill supports controller-service-repository layering, dependency injection, and middleware composition. Generated code is modular and easy to extend without modifying generated files.
Use Cases
- Scaffold a complete REST API from a data model description
- Generate Express/Fastify route handlers with validation
- Create authentication and authorization middleware
- Auto-generate OpenAPI 3.1 specification from code
Pros & Cons
Pros
- +Generates production-quality API code with security best practices built in
- +Supports multiple frameworks while maintaining idiomatic patterns
- +OpenAPI docs are always in sync with implementation
- +Validation and error handling included by default
Cons
- -Complex business logic still requires manual implementation after scaffolding
- -Framework-specific advanced features may not be fully covered
Related AI Tools
Claude
Anthropic's AI assistant built for thoughtful analysis and safe, nuanced conversations
- 200K token context window for massive document processing
- Artifacts — interactive side-panel for code, docs, and visualizations
- Projects with persistent context and custom instructions
Cursor
AI-native code editor with deep multi-model integration and agentic coding
- AI-native Cmd+K inline editing and generation
- Composer Agent for autonomous multi-file changes
- Full codebase indexing and context awareness
Bolt.new
AI app builder with in-browser WebContainers for instant full-stack apps
- In-browser WebContainers for zero-latency development
- Full-stack app generation from natural language prompts
- Live preview with hot module replacement
Related Skills
GraphQL Schema Designer
Design GraphQL schemas with type definitions, resolver generation, pagination, and N+1 query prevention using DataLoader.
Prisma ORM Workflow
Design Prisma schemas, generate migrations, optimize queries, and implement type-safe database access patterns.
Error Handling Patterns
Implement comprehensive error handling with typed errors, recovery strategies, logging integration, and user-friendly messages.
FAQ
What does API Builder do?
What platforms support API Builder?
What are the use cases for API Builder?
What tools work with API Builder?
100+ free AI tools
Writing, PDF, image, and developer tools — all in your browser.
Next Step
Use the skill detail page to evaluate fit and install steps. For a direct browser workflow, move into a focused tool route instead of staying in broader support surfaces.