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Resources & HTTP Methods
resource-oriented URLs GET collection GET single resource POST create resource PUT full replacement PATCH partial update DELETE resource HEAD request
Status Codes & Errors
200 OK 201 Created with Location 204 No Content 400 Bad Request 401 Unauthorized 403 Forbidden 404 Not Found 409 Conflict
Representations & Headers
Content-Type Accept negotiation Authorization Bearer token ETag If-None-Match Cache-Control Location header Link header pagination
Querying Collections
filter query parameters sorting offset pagination cursor pagination field selection search parameter date-range filtering multi-value filters
Reliability & Security
idempotency keys rate limiting CORS CSRF distinction for APIs input validation mass-assignment protection request correlation IDs timeouts and retries
Versioning & Documentation
URI versioning header versioning OpenAPI schema operationId request body schema response schema examples in OpenAPI deprecation headers
REST API Design / Representations & Headers

ETag

Learn ETag in REST API Design with a dedicated explanation, a concept-specific example, practical cautions, and a mastery check.

12 min read • Intermediate
rest-api-020.http
http 
HTTP/1.1 200 OK
ETag: "order-42-v7"
Content-Type: application/json

{"id":42,"version":7}
What to watch
Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

ETag Mastery Check →
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Authorization Bearer token
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If-None-Match