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A worked example

HTTP response map

One exchange at a time. Read what changes, then explain it in your own words before moving on.

  1. Meet the components
  2. Follow the steps
  3. Compare an example
  4. Check your understanding
Interactive Lab

HTTP response map

Select a status and watch where the request is handled.

Steps1. GET guide 2. Forward 3. 200 4. 200
Click a box or choose its name to learn what it means.
BrowserReadyGatewayReadyAPI serviceReadyBrowserReadyGatewayReadyAPI serviceReady
Ready to trace200 OK
Before you start · 4 steps200 OK

A successful request returns a representation.

How to use this example

Select Next step to read at your own pace, or Animate step to watch one exchange. Nothing advances until you choose.

Inspect components & read every step
  • Browser

    The program you use to open websites.

    Example: Your browser requests a web page and displays the response.

  • Gateway

    A system between a client and services that routes requests and may apply checks.

    Example: It may reject a request over a configured rate limit before it reaches a service.

  • API service

    A system that accepts structured requests from other software and returns results.

    Example: A weather service returns the forecast requested by an app.

200 OK

A successful request returns a representation.

  1. Browser Gateway: GET guide. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 200. A successful request returns a representation. Example response: Representation returned
  4. Gateway Browser: 200. The gateway returns the response to the client.

201 Created

Creation succeeds; the Location header can identify the new resource.

  1. Browser Gateway: POST order. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 201. Creation succeeds; the Location header can identify the new resource. Example response: Location: /orders/42
  4. Gateway Browser: 201. The gateway returns the response to the client.

204 No Content

The operation succeeds without response content.

  1. Browser Gateway: DELETE item. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 204. The operation succeeds without response content. Example response: No response body
  4. Gateway Browser: 204. The gateway returns the response to the client.

301 Moved Permanently

The client learns a permanent redirect; method handling requires care.

  1. Browser Gateway: GET old URL. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 301. The client learns a permanent redirect; method handling requires care. Example response: Location: /new
  4. Gateway Browser: 301. The gateway returns the response to the client.

400 Bad Request

The server rejects malformed input without leaking internals.

  1. Browser Gateway: Malformed request. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 400. The server rejects malformed input without leaking internals. Example response: Safe client error
  4. Gateway Browser: 400. The gateway returns the response to the client.

401 Unauthorized

The private endpoint requires valid authentication credentials.

  1. Browser Gateway: No valid credentials. The request reaches the edge.
  2. Gateway Browser: 401. The private endpoint requires valid authentication credentials. Example response: WWW-Authenticate

403 Forbidden

The server refuses the operation despite understanding the request.

  1. Browser Gateway: Other user’s record. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 403. The server refuses the operation despite understanding the request. Example response: No protected body
  4. Gateway Browser: 403. The gateway returns the response to the client.

404 Not Found

The server cannot find the resource or chooses not to disclose it.

  1. Browser Gateway: Unknown path. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 404. The server cannot find the resource or chooses not to disclose it. Example response: Resource unavailable
  4. Gateway Browser: 404. The gateway returns the response to the client.

429 Too Many Requests

This example limiter asks the client to wait; retry guidance is policy-specific.

  1. Browser Gateway: Request burst. The request reaches the edge.
  2. Gateway Browser: 429. This example limiter asks the client to wait; retry guidance is policy-specific. Example response: Retry-After: 30

500 Server Error

An unexpected server failure is recorded privately, not exposed as a stack trace.

  1. Browser Gateway: Valid request. The request reaches the edge.
  2. Gateway API service: Forward. This example passes the edge checks.
  3. API service Gateway: 500. An unexpected server failure is recorded privately, not exposed as a stack trace. Example response: Safe error response
  4. Gateway Browser: 500. The gateway returns the response to the client.

Fictional teaching trace. One moving dot represents an exchange, not a measured network capture.