# Claude Opus 5.5

> Anthropic's Claude Opus 5.5 is the successor to Claude Opus 5 for long-running agentic coding and knowledge work. It delivers Fable 5.1-level performance at 40% lower cost ($4 / $20 per million input / output tokens), with adaptive thinking always on, 1M-token context, vision input, and tool use. Built for multi-step changes in large codebases, code review and bug finding, financial and scientific analysis, and reading dense charts and diagrams.

**ID**: `anthropic/claude-opus-5-5`  
**Creator**: Anthropic  
**Category**: text  
**Context**: 1M tokens  
**Input**: $4.00/M  
**Output**: $20.00/M  
**Released**: 2026-09-22  
**Web page**: https://anyrouter.dev/model/anthropic/claude-opus-5-5

**Input modalities**: text, image  
**Output modalities**: text  

**Capabilities**: chat, streaming, function-calling, coding, vision, reasoning

**Aliases**: `claude-opus-5-5`, `claude-opus-5.5`, `anthropic/claude-opus-5-5`, `anthropic/claude-opus-5.5`, `claude-opus-5-5-20260921`, `anthropic/claude-opus-5.5-20260921`

## Usage

**Endpoint**: `POST https://anyrouter.dev/api/v1/chat/completions`

```bash
curl https://anyrouter.dev/api/v1/chat/completions \
  -H "Authorization: Bearer $ANYROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "anthropic/claude-opus-5-5",
  "messages": [
    {
      "role": "user",
      "content": "Say hi in 3 words."
    }
  ]
}'
```

## Providers

| Provider | Input | Output |
| --- | --- | --- |
| anthropic-byok | $0 | $0 |
| openrouter-byok | $0 | $0 |
| opencode-zen-byok | $0 | $0 |
| cline-byok | $0 | $0 |

## Benchmarks

- **GPQA Diamond**: 0.9
- **HLE**: 0.5

## Source

- Upstream docs: https://platform.claude.com/docs/en/models/opus-5-5/overview