# Claude Opus 5

## Best for

Anthropic Opus 5 for demanding coding, review, and long-horizon agents

## When not to use

Image, audio, or video input on this route — text only. Not Fable 5.1 when you want the cheaper, more concise coding and knowledge-work upgrade. Call it as `claude-opus-5`.

## Overview

Claude Opus 5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work. It is particularly strong at end-to-end software tasks, code review and bug finding, analysis of charts and documents, complex office deliverables, and coordinating parallel subagents.

The model maintains strong instruction following and tool use across extended tasks, while remaining effective at lower effort settings for workloads that prioritize latency and token efficiency.

| | |
| --- | --- |
| API identifier | `claude-opus-5` |
| Developer | Anthropic |
| Context window | 262,144 tokens |
| Supports | text, reasoning, tool-use |
| Status | Serving |

## Rates

USD per 1M tokens, on-demand tier.

| Input | Cached input | Output |
| --- | --- | --- |
| $5.00 | $0.50 | $25.00 |

## Call it

Put `claude-opus-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",
    "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).