# Claude Opus 5.5

## Best for

Long coding or research tasks that benefit from adaptive thinking

## When not to use

Audio or video input. If higher-effort Opus evals still fall short, use Fable 5.1 for the most demanding reasoning and long-horizon work. Call it as `claude-opus-5.5`.

## Overview

Claude Opus 5.5 is Anthropic's recommended model for most workloads. It supports adaptive thinking, tool use, and image input, with a 1,000,000-token context window for extended coding, research, and knowledge work.

| | |
| --- | --- |
| API identifier | `claude-opus-5.5` |
| Developer | Anthropic |
| Context window | 1,000,000 tokens |
| Supports | text, reasoning, tool-use, image input, vision |
| Status | Serving |

## Rates

USD per 1M tokens, on-demand tier.

| Input | Cached input | Output |
| --- | --- | --- |
| $4.00 | $0.20 | $20.00 |

## Call it

Put `claude-opus-5.5` in the `model` field. The same request works against the Anthropic Messages API — see [API Compatibility](https://inference.boundless.network/docs/api-compatibility).

```bash
curl https://api.inference.boundless.network/v1/chat/completions \
  -H "Authorization: Bearer $BOUNDLESS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-5.5",
    "messages": [{
      "content": "Say hello",
      "role": "user"
    }]
  }'
```

Every model we serve is listed at [Models](https://inference.boundless.network/models); the rate card in full is on [Pricing](https://inference.boundless.network/docs/pricing).