REST API ডিজাইন — সম্পূর্ণ গাইড

REST Principles

Resource-based, Stateless, Cacheable, Uniform interface, Layered।

HTTP Methods

Method	Use	Idempotent
GET	Retrieve	✅
POST	Create	❌
PUT	Replace	✅
PATCH	Partial	❌
DELETE	Remove	✅

Status Codes

• 2xx — 200, 201, 204
• 3xx — 301, 304
• 4xx — 400, 401, 403, 404, 409, 422, 429
• 5xx — 500, 502, 503

Resource Naming ⭐

✅ /api/users (plural)
✅ /api/users/123/orders
❌ /api/getUsers (verb)
❌ /api/user_list

Filtering, Pagination

GET /api/products?category=electronics&minPrice=100
GET /api/products?sort=price&order=desc
GET /api/products?page=2&limit=20
GET /api/products?fields=id,name (sparse)

Versioning

• URL: /api/v1/users (popular)
• Header: Accept: application/vnd.app.v2+json
• Query: ?version=2

Response Format

{
  "data": [...],
  "meta": {"page": 1, "total": 250},
  "links": {"next": "/api/users?page=2"}
}

// Error
{
  "error": {
    "code": "VALIDATION_FAILED",
    "message": "Invalid input",
    "details": [{"field": "email", "msg": "Invalid"}]
  },
  "request_id": "abc-123"
}

HATEOAS (Maturity L3)

{
  "id": 1,
  "_links": {
    "self": {"href": "/users/1"},
    "orders": {"href": "/users/1/orders"}
  }
}

Best Practices

• Consistent naming
• UTC ISO 8601 timestamp
• HTTPS, gzip
• Idempotency-Key header for POST
• ETag caching
• OpenAPI/Swagger doc