Create a Response

POST/v1/responses

AuthorizationLink to section

Authorizationstringrequired

Your Mixedbread API key as a bearer token. Format: `Bearer YOUR_API_KEY`.

Request BodyLink to section

modelstringdefault: toast-1

Public model ID.

instructionsstring | null

System-level instructions for this response. New instructions replace instructions from a previous response.

tool_choicestring | objectdefault: auto

Controls function selection. Use `auto`, `none`, `required`, or force a function with `{ type: 'function', name: '...' }`.

storebooleandefault: true

Persist the response so it can be retrieved and continued later. Set to `false` to prevent response content from being stored for later retrieval.

previous_response_idstring | null

ID of a stored response to continue. Send only the new input for the next turn.

streambooleandefault: false

Return semantic server-sent events such as `response.output_text.delta` and a terminal `response.completed` event.

temperaturenumber | null

top_pnumber | null

max_output_tokensinteger | null

Maximum tokens to generate for the response.

Constraints

•Minimum: 16

parallel_tool_callsbooleandefault: true

Allow the model to request multiple function calls in one response.

metadataobject | null

Up to 16 string key-value pairs. Keys may contain up to 64 characters and values up to 512 characters.

Response BodyLink to section

idstringrequired

Unique response ID, prefixed with `resp_`.

objectstringrequireddefault: response

created_atnumberrequired

Unix timestamp when the response was created.

completed_atnumber | null

Unix timestamp when generation completed.

statusenumrequired

errorobject | null

Error code and message when the response failed.

incomplete_detailsobject | null

Why the response is incomplete, such as reaching `max_output_tokens`.

modelstringrequired

The stable public model ID, `toast-1`.

parallel_tool_callsboolean

Whether parallel function calls were allowed.

tool_choicestring | object

Function selection mode used for the response.

toolsarray

Function definitions configured for the response.

max_output_tokensinteger | null

previous_response_idstring | null

The previous response continued by this response.

usageobject | null

Input, output, cached, reasoning, and total token counts.

metadataobject | null

Metadata copied from the request.

titlestring | null

Short display title for the stored conversation.

Request

POST/v1/responses

from openai import OpenAI

client = OpenAI(
    base_url="https://api.mixedbread.com/v1",
    api_key="YOUR_API_KEY",
)

response = client.responses.create(
    model="toast-1",
    input="What is a search agent?",
)

print(response.output_text)

Response

JSON

{
  "id": "resp_abc123",
  "object": "response",
  "created_at": 1786622400,
  "status": "completed",
  "completed_at": 1786622401,
  "error": null,
  "incomplete_details": null,
  "instructions": null,
  "model": "toast-1",
  "output": [
    {
      "type": "message",
      "id": "msg_abc123",
      "status": "completed",
      "role": "assistant",
      "content": [
        {
          "type": "output_text",
          "annotations": [],
          "text": "A search agent plans queries, gathers evidence with tools, and synthesizes an answer.",
          "logprobs": []
        }
      ]
    }
  ],
  "parallel_tool_calls": true,
  "temperature": null,
  "tool_choice": "auto",
  "tools": [],
  "top_p": null,
  "background": false,
  "max_output_tokens": null,
  "previous_response_id": null,
  "reasoning": null,
  "service_tier": "default",
  "text": null,
  "truncation": "disabled",
  "usage": {
    "input_tokens": 15,
    "input_tokens_details": {
      "cached_tokens": 0
    },
    "output_tokens": 19,
    "output_tokens_details": {
      "reasoning_tokens": 0
    },
    "total_tokens": 34
  },
  "metadata": null,
  "safety_identifier": null,
  "prompt_cache_key": null,
  "user": null,
  "title": "What is a search agent?"
}

Stored response lifecycleLink to section

Responses created with store: true can also use the OpenAI-compatible retrieve, delete, and input-items endpoints. These operations use the same REST paths and OpenAI SDK method names. Use the Mixedbread base URL and API key shown in the examples above.

Operation	REST endpoint	Python	TypeScript	Supported query parameters
Retrieve a response	`GET /v1/responses/{response_id}`	`client.responses.retrieve(response_id)`	`client.responses.retrieve(responseId)`	`stream`, `starting_after`
Delete a response	`DELETE /v1/responses/{response_id}`	`client.responses.delete(response_id)`	`client.responses.delete(responseId)`	None
List input items	`GET /v1/responses/{response_id}/input_items`	`client.responses.input_items.list(response_id)`	`client.responses.inputItems.list(responseId)`	`limit`, `order`, `after`

Mixedbread supports the OpenAI lifecycle shape for text messages and client-executed function items. OpenAI options or item types not documented on this page are not supported. Deleting a stored response also deletes its persisted conversation chain.