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

# Messages

> Anthropic-compatible messages endpoint.

The messages endpoint is compatible with Anthropic's API.

## Endpoint

```
POST https://gateway.muxx.dev/v1/messages
```

## Request

```bash theme={null}
curl https://gateway.muxx.dev/v1/messages \
  -H "Content-Type: application/json" \
  -H "X-Muxx-Api-Key: muxx_sk_live_xxxxxxxxxxxx" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-3-5-sonnet-20241022",
    "max_tokens": 1024,
    "messages": [
      {"role": "user", "content": "Hello!"}
    ]
  }'
```

## Parameters

| Parameter   | Type    | Required | Description           |
| ----------- | ------- | -------- | --------------------- |
| model       | string  | Yes      | Model ID              |
| max\_tokens | integer | Yes      | Max output tokens     |
| messages    | array   | Yes      | Conversation messages |
| system      | string  | No       | System prompt         |
| temperature | number  | No       | Randomness (0-1)      |
| stream      | boolean | No       | Enable streaming      |
| tools       | array   | No       | Tool definitions      |

## Response

```json theme={null}
{
  "id": "msg_abc123",
  "type": "message",
  "role": "assistant",
  "content": [
    {
      "type": "text",
      "text": "Hello! How can I help you today?"
    }
  ],
  "model": "claude-3-5-sonnet-20241022",
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 10,
    "output_tokens": 15
  }
}
```

## Muxx Headers

### Request Headers

| Header              | Description                  |
| ------------------- | ---------------------------- |
| `X-Muxx-Api-Key`    | Your Muxx API key (required) |
| `X-Muxx-Metadata`   | Custom metadata JSON         |
| `anthropic-version` | Anthropic API version        |

### Response Headers

| Header              | Description            |
| ------------------- | ---------------------- |
| `X-Muxx-Request-Id` | Unique request ID      |
| `X-Muxx-Cache`      | `HIT` or `MISS`        |
| `X-Muxx-Cost`       | Calculated cost in USD |

## Streaming

```bash theme={null}
curl https://gateway.muxx.dev/v1/messages \
  -H "Content-Type: application/json" \
  -H "X-Muxx-Api-Key: muxx_sk_live_xxxxxxxxxxxx" \
  -d '{
    "model": "claude-3-5-sonnet-20241022",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": true
  }'
```

Response is server-sent events:

```
event: content_block_delta
data: {"type":"content_block_delta","delta":{"type":"text_delta","text":"Hello"}}

event: message_stop
data: {"type":"message_stop"}
```

## Supported Models

* `claude-3-5-sonnet-20241022`
* `claude-3-5-haiku-20241022`
* `claude-3-opus-20240229`
* `claude-3-sonnet-20240229`
* `claude-3-haiku-20240307`