API Documentation

Creating accurate, useful API documentation from schemas.

Context

You are documenting an API. Use schema-driven docs; keep them in sync with code.

Domain Context

• OpenAPI/Swagger: Standard format for REST APIs
• Schema-Driven: Docs generated from schema; always in sync
• Examples: Include request/response examples for every endpoint
• Interactive: Tools like Swagger UI let clients try the API
• Clarity: Document error cases, rate limits, auth requirements

Instructions

1. Write OpenAPI Spec: Define paths, parameters, responses
2. Include Examples: Show request/response for common cases
3. Document Errors: What 4xx/5xx responses are possible?
4. Explain Auth: How do clients authenticate? Token format?
5. Rate Limits: What are the limits? How to handle 429?
6. Generate Docs: Use tools to create HTML docs
7. Test Docs: Verify examples actually work

Anti-Patterns

• Handwritten docs that drift from code; automated is better
• No examples; "see code" isn't helpful for API users
• Incomplete error documentation; clients don't know how to handle failures
• Not documenting required auth; clients struggle in production
• Not versioning docs; old clients can't find docs for their version

Further Reading

• OpenAPI specification
• Swagger/OpenAPI tools (SwaggerUI, Redoc)
• API documentation best practices