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name: rest-patterns description: "Quick reference for RESTful API design patterns, HTTP semantics, caching, and rate limiting. Triggers on: rest api, http methods, status codes, api design, endpoint design, api versioning, rate limiting, caching headers." allowed-tools: "Read Write"

REST Patterns

Quick reference for RESTful API design patterns and HTTP semantics.

HTTP Methods

Method	Purpose	Idempotent	Cacheable
GET	Retrieve resource(s)	Yes	Yes
POST	Create new resource	No	No
PUT	Replace entire resource	Yes	No
PATCH	Partial update	Maybe	No
DELETE	Remove resource	Yes	No

Essential Status Codes

Code	Name	Use
200	OK	Success with body
201	Created	POST success (add Location header)
204	No Content	Success, no body
400	Bad Request	Invalid syntax
401	Unauthorized	Not authenticated
403	Forbidden	Not authorized
404	Not Found	Resource doesn't exist
422	Unprocessable	Validation error
429	Too Many Requests	Rate limited
500	Server Error	Internal failure

Resource Design

GET    /users              # List
POST   /users              # Create
GET    /users/{id}         # Get one
PUT    /users/{id}         # Replace
PATCH  /users/{id}         # Update
DELETE /users/{id}         # Delete

# Query parameters
GET /users?page=2&limit=20          # Pagination
GET /users?sort=created_at:desc     # Sorting
GET /users?role=admin               # Filtering

Security Checklist

• HTTPS/TLS only
• OAuth 2.0 or JWT for auth
• Validate all inputs
• Rate limit per client
• CORS headers configured
• No sensitive data in URLs
• Use no-store for sensitive responses

Common Mistakes

Mistake	Fix
Verbs in URLs	/getUsers → /users
Deep nesting	Flatten or use query params
200 for errors	Use proper 4xx/5xx
No pagination	Always paginate collections
Missing rate limits	Protect against abuse

Quick Reference

Task	Pattern
Paginate	?page=2&limit=20
Sort	?sort=field:asc
Filter	?status=active
Sparse fields	?fields=id,name
Include related	?include=orders

When to Use

• Designing new API endpoints
• Choosing HTTP methods and status codes
• Implementing caching headers
• Setting up rate limiting
• Structuring error responses

Additional Resources

For detailed patterns, load:

• ./references/status-codes.md - Complete status code reference with examples
• ./references/caching-patterns.md - Cache-Control, ETag, CDN patterns
• ./references/rate-limiting.md - Rate limiting strategies and headers
• ./references/response-formats.md - Errors, versioning, bulk ops, HATEOAS