---
title: "Responses"
method: POST
path: "/models/v2/openai/v1/responses"
---

# Responses

`POST /models/v2/openai/v1/responses`

Sends input to an OpenAI compatible Responses model and returns a unified response object. Supports text and chat-style input, streaming, tools, and (for supported reasoning models) "thinking" via the `reasoning` object. To send a request to a closed source provider, prefix your model with their provider name, e.g. `openai/gpt-5.1`.

## Headers

- `Authorization` string, required

## Request body

- ResponsesRequest
  - `model` string, required — The ID of the model to run (e.g., `anthropic/claude-opus-4-5`, `openai/gpt-5.1`)
  - `input` union, required — The input to the model. Can be a string (simple prompt) or an array of chat-style messages. For richer multimodal inputs, use the array form with multi-part `content`.
    - string
    - ResponsesInputMessage[]
      - `role` 'system' | 'user' | 'assistant' | 'developer' | 'tool', required — The role of the message sender
      - `content` union, required
        - string — Plain text content
        - object[] — Multi-part content (text, images, etc.) - provider/model dependent
          - `type` string — Content part type (e.g. `input_text`, `input_image`)
          - `text` string — Text for `input_text` parts
          - `image_url` string — URL or data URL for `input_image` parts
  - `max_output_tokens` integer — Maximum number of tokens to generate (counts reasoning + visible output for reasoning models)
  - `temperature` number — Sampling temperature
  - `stream` boolean — Whether to stream SSE events
  - `reasoning` ReasoningConfig — Optional "thinking" controls for supported reasoning models.
    - `effort` string — Reasoning effort level. Exact allowed values may be model-dependent.
    - `summary` 'none' | 'auto' | 'detailed' — Whether/how to return a reasoning summary (not full chain-of-thought).
  - `tools` ToolDefinition[] — Optional tool definitions for function/tool calling
    - `type` 'function', required
    - `function` object, required
      - `name` string
      - `description` string
      - `parameters` object — JSON Schema for tool parameters
  - `tool_choice` union — Tool selection behavior
    - 'auto' | 'none' | 'required'
    - object — Force a specific tool (provider/model dependent)
  - `metadata` object — Arbitrary key/value metadata to attach to the request
  - `user` string — End-user identifier (if supported)
  - `include` string[] — Optional list of extra fields to include in the response (e.g. logprobs). Example values may include `message.output_text.logprobs` (provider/model dependent).
  - `top_logprobs` integer — Number of most likely tokens to return at each position (if logprobs are included)

## Response `200`

Successful response

- ResponsesResponse
  - `id` string, required — Unique ID for this response
  - `object` string, required — Type of returned object (usually `response`)
  - `created` integer, required — Unix timestamp of response creation
  - `model` string, required — Model used to generate the response
  - `output` union[] — Output items (messages, reasoning summaries, tool calls, etc.)
    - union
      - ResponsesMessageItem
        - `type` 'message', required
        - `role` string, required
        - `content` ResponsesOutputTextItem[], required
          - `type` 'output_text'
          - `text` string
      - ResponsesReasoningItem
        - `type` 'reasoning'
        - `summary` object[] — Optional reasoning summary items (when `reasoning.summary` is enabled)
          - `type` 'summary_text'
          - `text` string
  - `output_text` string — Convenience field containing concatenated output text (when applicable)
  - `usage` object — Token usage details (shape may vary by provider)

## Other responses

- `400` — Bad request
- `500` — Internal server error

---

[API](https://skmtc.net/bytez/apis/closed-source-model-api.md) · [All operations](https://skmtc.net/bytez/apis/closed-source-model-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/bytez/closed-source-model-api/versions/d64c9c733afe/schema)