OpenAI Responses API mock: completion and partial output

Generate Response: Temporary rate limit

Documented Synthetic illustrative example from the catalogue, not a live capture. Run only after installing your own receiver. Replace <your-receiver-token> locally; no request is sent from this page.

HTTP 429 · rate_limit_error · slow_down · Retry-After: 5

curl / Bash request

printf '%s' '{"model":"gpt-4.1","input":"Say hello"}' | \
curl -i -X POST \
  'https://nottherealapi.com/r/<your-receiver-token>/v1/responses' \
  -H 'Authorization: Bearer synthetic-openai-token' \
  -H 'Content-Type: application/json' \
  --data-binary @-

PowerShell request

$body = '{"model":"gpt-4.1","input":"Say hello"}'
Invoke-WebRequest `
    -UseBasicParsing `
    -Uri 'https://nottherealapi.com/r/<your-receiver-token>/v1/responses' `
    -Method POST `
    -Headers @{
    Authorization = 'Bearer synthetic-openai-token'
    } `
    -ContentType 'application/json' `
    -Body ([Text.Encoding]::UTF8.GetBytes($body))

Selected synthetic response

HTTP 429
content-type: application/json
retry-after: 5
x-ratelimit-limit-requests: 60
x-ratelimit-remaining-requests: 0
x-ratelimit-reset-requests: 1s

{
  "error": {
    "message": "Request rate increased too quickly. Reduce traffic and retry.",
    "type": "rate_limit_error",
    "code": "slow_down"
  }
}

Stream Response: Error event after partial text

Representative Synthetic illustrative example from the catalogue, not a live capture. Run only after installing your own receiver. Replace <your-receiver-token> locally; no request is sent from this page.

HTTP 200 · SSE · Stream error after partial output

curl / Bash request

printf '%s' '{"model":"gpt-4.1","input":"Say hello","stream":true}' | \
curl -i --no-buffer -X POST \
  'https://nottherealapi.com/r/<your-receiver-token>/v1/responses' \
  -H 'Authorization: Bearer synthetic-openai-token' \
  -H 'Content-Type: application/json' \
  --data-binary @-

PowerShell request

$body = '{"model":"gpt-4.1","input":"Say hello","stream":true}'
Invoke-WebRequest `
    -UseBasicParsing `
    -Uri 'https://nottherealapi.com/r/<your-receiver-token>/v1/responses' `
    -Method POST `
    -Headers @{
    Authorization = 'Bearer synthetic-openai-token'
    } `
    -ContentType 'application/json' `
    -Body ([Text.Encoding]::UTF8.GetBytes($body))

Selected synthetic response

HTTP 200
content-type: text/event-stream; charset=utf-8

event: response.created
data: {"type":"response.created","response":{"id":"resp_example_001","object":"response","created_at":1792238400,"model":"gpt-4.1","status":"in_progress","error":null,"incomplete_details":null,"output":[],"parallel_tool_calls":true,"tools":[],"tool_choice":"auto","metadata":{},"usage":null},"sequence_number":0}

event: response.in_progress
data: {"type":"response.in_progress","response":{"id":"resp_example_001","object":"response","created_at":1792238400,"model":"gpt-4.1","status":"in_progress","error":null,"incomplete_details":null,"output":[],"parallel_tool_calls":true,"tools":[],"tool_choice":"auto","metadata":{},"usage":null},"sequence_number":1}

event: response.output_item.added
data: {"type":"response.output_item.added","output_index":0,"item":{"id":"msg_example_001","type":"message","role":"assistant","status":"in_progress","content":[]},"sequence_number":2}

event: response.content_part.added
data: {"type":"response.content_part.added","item_id":"msg_example_001","output_index":0,"content_index":0,"part":{"type":"output_text","text":"","annotations":[],"logprobs":[]},"sequence_number":3}

event: response.output_text.delta
data: {"type":"response.output_text.delta","item_id":"msg_example_001","output_index":0,"content_index":0,"delta":"Hello ","logprobs":[],"sequence_number":4}

event: error
data: {"type":"error","code":"server_error","message":"Synthetic mid-stream failure","param":null,"sequence_number":5}

Events above are the fixed fixture sequence. Delivery timing is simulated; see the full behaviour list for completion, error and early EOF choices.