Cancel Response

POST

responses

{response_id}

cancel

curl -X POST https://gateway.bud.studio/v1/responses/resp_abc123/cancel \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "x-model-name: gpt-4"

{
  "id": "resp_abc123",
  "object": "response",
  "status": "cancelled",
  "created_at": 1699000000,
  "cancelled_at": 1699000030,
  "conversation": { "id": "conv_9f2c1d7b4a6e08f35c1d2b7e4a9f6038" },
  "output": [
    {
      "id": "msg_xyz",
      "type": "message",
      "role": "assistant",
      "status": "in_progress",
      "content": [
        { "type": "output_text", "text": "The capital of Fra", "annotations": [] }
      ]
    }
  ]
}

curl -X POST https://gateway.bud.studio/v1/responses/resp_abc123/cancel \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "x-model-name: gpt-4"

{
  "id": "resp_abc123",
  "object": "response",
  "status": "cancelled",
  "created_at": 1699000000,
  "cancelled_at": 1699000030,
  "conversation": { "id": "conv_9f2c1d7b4a6e08f35c1d2b7e4a9f6038" },
  "output": [
    {
      "id": "msg_xyz",
      "type": "message",
      "role": "assistant",
      "status": "in_progress",
      "content": [
        { "type": "output_text", "text": "The capital of Fra", "annotations": [] }
      ]
    }
  ]
}

Headers

Parameter	Type	Required	Description
Authorization	string	Yes	Bearer authentication header
x-model-name	string	No	Model name for routing. Default: gpt-4-responses

Path Parameters

Parameter	Type	Required	Description
response_id	string	Yes	The ID of the response to cancel

What can be cancelled

The response is…	Result
a background run (`background: true`), still working	`200` — the run is stopped and the envelope comes back `cancelled`.
a streaming run, still in flight	`200` — the stream is ended (see below) and the model call is stopped so it stops billing.
an ordinary non-streaming run	`409 cannot_cancel_non_background` — there is nothing to interrupt: the result is returned to the request that is waiting for it.
already `cancelled`	`200`, idempotent — the existing envelope. A client cannot tell whether its cancel raced the stream’s own ending, so answering beats an error.
a background run, already `completed` / `failed` / `incomplete`	`200`, idempotent — the existing envelope.
a non-streaming run, already `completed` / `failed` / `incomplete`	`409 cannot_cancel_non_background`.
unknown, or owned by another API key	`404`.

The id is cancellable from the moment the run starts — including the id in the response.created frame, the first thing a stream sends.

409

{
  "error": {
    "message": "This response is not streaming, so there is nothing to interrupt: a synchronous result is returned to the request waiting for it. Only a streaming or a background response can be cancelled.",
    "type": "invalid_request_error",
    "code": "cannot_cancel_non_background"
  }
}

What the streaming client sees

The stream ends within one chunk of the cancel — the client keeps every byte the model had already produced — and the last frame it receives is:

event: response.incomplete
data: {"type":"response.incomplete","sequence_number":42,"response":{"id":"resp_abc123","status":"cancelled", ...}}

The event type is response.incomplete because OpenAI’s stream-event union has no response.cancelled member; the response object it carries says cancelled, which is what a later GET /v1/responses/{id} reports too — so the stream and the stored response never disagree about how the run ended. A cancel that arrives after the stream has already sent its terminal frame changes nothing about the answer: no second terminal frame is emitted, and the output that was delivered stays on the stored response.

Cancel works across replicas. A cancel served by a different pod than the one driving the stream is picked up from the stored response’s status within about two seconds, so the caller does not need to reach a particular instance.

What is kept

A cancelled run keeps what it had produced: the partial output that was streamed to the client is stored on the response rather than being discarded, so GET /v1/responses/{id} returns status: "cancelled" alongside the tokens that were actually delivered.

Supported Providers

Cancellation is provider-agnostic — it applies to any background or streaming response Bud is driving, whichever model is behind it.

curl -X POST https://gateway.bud.studio/v1/responses/resp_abc123/cancel \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "x-model-name: gpt-4"

{
  "id": "resp_abc123",
  "object": "response",
  "status": "cancelled",
  "created_at": 1699000000,
  "cancelled_at": 1699000030,
  "conversation": { "id": "conv_9f2c1d7b4a6e08f35c1d2b7e4a9f6038" },
  "output": [
    {
      "id": "msg_xyz",
      "type": "message",
      "role": "assistant",
      "status": "in_progress",
      "content": [
        { "type": "output_text", "text": "The capital of Fra", "annotations": [] }
      ]
    }
  ]
}

Introduction

Gateway APIs

Python SDK & CLI

Headers

Path Parameters

What can be cancelled

What the streaming client sees

What is kept

Supported Providers

​Headers

​Path Parameters

​What can be cancelled

​What the streaming client sees

​What is kept

​Supported Providers

Headers

Path Parameters

What can be cancelled

What the streaming client sees

What is kept

Supported Providers