GET

GET retrieves a representation of a resource. It's the most common HTTP method and the foundation of how the web works.

GET Characteristics

GET /api/users/123 HTTP/1.1
Host: api.example.com
Accept: application/json

→ Safe: Does not modify server state
→ Idempotent: Same request = same response
→ Cacheable: Responses can be cached
→ No request body (server ignores it)

GET Examples

# Get a single resource
GET /api/users/123

# Get a collection with filters
GET /api/users?status=active&role=admin

# Get with pagination
GET /api/products?page=2&limit=20

# Get with field selection
GET /api/users/123?fields=name,email

Response Handling

HTTP/1.1 200 OK
Content-Type: application/json
Cache-Control: max-age=300
ETag: "abc123"

{
  "id": 123,
  "name": "Alice",
  "email": "alice@example.com",
  "role": "admin",
  "createdAt": "2026-01-15T10:30:00Z"
}

GET Design Best Practices

1. Never use GET for mutations — Browsers prefetch, crawlers follow links
2. Use query parameters for filtering — Not path segments for filter values
3. Implement pagination — Limit response size
4. Support caching — Use ETag, Cache-Control headers
5. Return appropriate status codes — 200 for success, 404 for not found

Methods

• GET: Read (safe, idempotent)
• POST: Create
• PUT: Replace (idempotent)
• PATCH: Partial update
• DELETE: Remove (idempotent)

Headers

• Content-Type: Body format
• Cache-Control: Caching rules
• Authorization: Authentication
• Accept: Desired response format

Status Codes

• 2xx: Success
• 3xx: Redirection
• 4xx: Client error
• 5xx: Server error

Key Points

• Understanding GET is essential for production systems
• Always consider scalability and maintainability
• Test thoroughly before deploying to production
• Monitor performance and set up alerting

Common Patterns

1. Validation: Always validate input at the boundary
2. Error Handling: Use structured error responses
3. Logging: Log key events for debugging
4. Testing: Unit, integration, and load tests
5. Documentation: Keep docs updated with code changes