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

# Claude Opus 5.5

> Claude Opus model for long-running agentic coding and knowledge work.

Claude Opus model for long-running agentic coding and knowledge work.

## Model Information

| Field        | Description       |
| ------------ | ----------------- |
| `model`      | claude-opus-5-5   |
| `context`    | 1M tokens         |
| `max output` | 128K tokens       |
| `endpoint`   | POST /v1/messages |

Context and output sizes describe the model specification. Effective request limits, availability, and billing depend on the MixRoute route.

## Capabilities and Usage

* Accepts text and images; returns text and tool-use content blocks.
* Adaptive thinking is always on. Effort is configured with output\_config.effort; the default is medium. Do not send thinking.type=disabled or legacy budget\_tokens settings.

## Request Example

Set `MIXROUTE_API_KEY` before making the request.

```bash theme={null}
curl --request POST "https://api.mixroute.ai/v1/messages" \
  --header "Authorization: Bearer $MIXROUTE_API_KEY" \
  --header "Content-Type: application/json" \
  --header "anthropic-version: 2023-06-01" \
  --data '{
  "model": "claude-opus-5-5",
  "max_tokens": 1024,
  "messages": [
    {
      "role": "user",
      "content": "Explain the tradeoffs of database indexes."
    }
  ]
}'
```

## Request Fields

| Field        | Description                                           |
| ------------ | ----------------------------------------------------- |
| `model`      | Required. Use the exact model ID above.               |
| `messages`   | Required conversation messages with role and content. |
| `max_tokens` | Required output-token budget.                         |

Complete request format: [messages](/en/api-reference/endpoint/messages).