Quick Guide to RESTful API Design Principles & Standards

This concise guide combines best practices to help you design clean, consistent, and scalable RESTful APIs.

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⚙️ 1. Design Around Resources

• Use nouns, not verbs — e.g., /users, /orders/{id}.
• Keep URIs simple, consistent, and hierarchical.
• Avoid exposing internal database details.

🧭 2. Use Correct HTTP Methods

Action	Method	Example
Read	GET	/orders
Create	POST	/orders
Update	PUT or PATCH	/orders/{id}
Delete	DELETE	/orders/{id}

Ensure idempotency for PUT and DELETE requests.

🧱 3. Stateless & Cacheable

• Each request must contain all context — no server session state.
• Use caching headers like ETag and Last-Modified where appropriate.

📄 4. Use Standard Representations

• Prefer application/json as the default format.
• Set proper headers:
  • Content-Type for request format
  • Accept for desired response format

🧩 5. Pagination & Filtering

• Support ?limit=, ?offset=, or cursor-based pagination.
• Allow filtering and sorting — e.g., ?status=active&sort=desc.

🔢 6. Versioning

• Version via URI (e.g., /v1/) or headers.
• Never break existing clients — evolve your API gracefully.

🚦 7. Status Codes & Errors

• 200 – OK
• 201 – Created
• 204 – No Content
• 400 – Bad Request
• 404 – Not Found
• 500 – Server Error

Return clear JSON error messages with a code and description.

📘 8. Documentation & Specification

• Use OpenAPI (Swagger) or Postman Collections for design and documentation.
• Document endpoints, parameters, request/response examples.
• Mock and validate before implementation.

🧭 9. Consistency & Governance

• Follow organization-wide conventions for naming, versioning, and error handling.
• Maintain uniform design patterns — make every API feel familiar.

✅ 10. RESTful API Checklist

• [ ] Resource-based URIs
• [ ] Correct HTTP verbs
• [ ] Stateless operations
• [ ] Consistent JSON responses
• [ ] Pagination and filtering support
• [ ] Versioning strategy
• [ ] Meaningful error format
• [ ] OpenAPI documentation

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💡 In Short

Design first, stay consistent, be consumer-friendly, and evolve safely.