> ## Documentation Index
> Fetch the complete documentation index at: https://docs.airmux.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Responses

> Reference the Responses-compatible request fields, output items, restrictions, and streaming events.

```text theme={null}
POST /inf/v1/responses
```

The route always returns Responses-shaped output and errors.

## Request

```bash theme={null}
curl https://llm.example.com/inf/v1/responses \
  -H "Authorization: Bearer $AIRMUX_INFERENCE_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "openai/gpt-4o-mini",
    "input": "Explain request routing in one sentence",
    "max_output_tokens": 128,
    "store": false
  }'
```

## Supported fields

| Field                  | Notes                                                                       |
| ---------------------- | --------------------------------------------------------------------------- |
| `model`                | Required catalog model ID                                                   |
| `input`                | String or supported input-item array                                        |
| `instructions`         | Prepended as a system message                                               |
| `stream`               | Boolean                                                                     |
| `max_output_tokens`    | Maximum generated tokens; maps to the gateway's internal output-token limit |
| `temperature`, `top_p` | Sampling fields                                                             |
| `tools`                | Function tools only; hosted tools are rejected                              |
| `tool_choice`          | `auto`, `none`, `required`, or named function                               |
| `parallel_tool_calls`  | Boolean                                                                     |
| `reasoning`            | Reasoning configuration                                                     |
| `text.format`          | `text`, `json_object`, or `json_schema`                                     |
| `store`                | Only `false` or omitted is supported                                        |
| `include`              | Omitted, empty, or `reasoning.encrypted_content`                            |

Unknown top-level fields are rejected with `unsupported_feature` on this surface.

## Response

The buffered response contains `output` items for assistant messages, reasoning, and function calls. It also includes
usage plus an additive `gateway` object.

```json theme={null}
{
  "id": "019...",
  "object": "response",
  "status": "completed",
  "model": "openai/gpt-4o-mini",
  "output": [
    {
      "type": "message",
      "id": "msg_0",
      "role": "assistant",
      "status": "completed",
      "content": [{"type": "output_text", "text": "Requests are routed by catalog model, policy, and eligible credential."}]
    }
  ],
  "gateway": {"finish_reason": "stop", "adjustments": []}
}
```

## Streaming

The stream emits named SSE events such as `response.created`, `response.output_item.added`, text or function-argument
deltas, `response.output_item.done`, and `response.completed`. A failure after streaming begins is emitted as an `error`
event.