Question 1

How do I write API documentation?

Accepted Answer

API documentation structure: Overview (purpose, base URL, versioning). Authentication (API keys, OAuth, headers). Endpoints (each endpoint with method, path, parameters, request body, response). Errors (status codes, error format). Rate limits (limits, retry strategies). Examples (code in multiple languages). Changelog (updates, deprecations). Tools: Swagger/OpenAPI for interactive docs, Postman for testing, Redoc for rendering. Good docs: self-service, no support tickets needed.

Question 2

What is OpenAPI/Swagger?

Accepted Answer

OpenAPI (formerly Swagger): standard format for REST API documentation. YAML/JSON file describing: endpoints, methods, parameters, request/response schemas, authentication. Benefits: machine-readable, auto-generate docs, client SDKs, validation, testing. Swagger UI: interactive documentation (try endpoints in browser). Swagger Editor: write and validate OpenAPI specs. Use OpenAPI 3.0+ for modern features. Tools: swagger-jsdoc, swagger-ui-express for Node.js integration.

Question 3

What are the RESTful API methods?

Accepted Answer

RESTful methods: GET (retrieve data, no body, safe/idempotent). POST (create new resource, body required, not idempotent). PUT (update entire resource, body required, idempotent). PATCH (partial update, body with changes, not always idempotent). DELETE (remove resource, no body, idempotent). HEAD (get headers only, no body). OPTIONS (get allowed methods). Idempotent = same result from repeated calls. Use correct method for operation type.

Question 4

How do I document API errors?

Accepted Answer

Error documentation: List all error codes (400, 401, 403, 404, 429, 500). Consistent error format: { error: { code: 'USER_NOT_FOUND', message: '...', details: {} } }. Include: HTTP status code, error code (machine-readable), message (human-readable), details (context). Document each error: when it occurs, how to fix. Example responses for each error. Retry guidance for 5xx/429. Good error docs = developers can debug without contacting support.

Question 5

What should API rate limit documentation include?

Accepted Answer

Rate limit documentation: Limits (requests per minute/hour/day), headers returned (X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset), response when exceeded (429 status, Retry-After header), retry strategies (exponential backoff, queue requests), how to request higher limits (contact support, upgrade plan). Example: 100 requests/minute, X-RateLimit headers in every response, 429 with retry guidance. Clear rate limit docs prevent frustration and abuse.

API Documentation Guide

RESTful Methods

Documentation Sections

Best Practices

Documentation Tools

API Doc Checklist