As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/claude-opus-4-6/

# Claude Opus 4.6

Anthropic, Claude 4 family. Status: legacy. Type: reasoning model. Released: 2026-02-05. Training cutoff: 2025-05.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| Anthropic API (Claude API) | `claude-opus-4-6` | https://api.anthropic.com/v1/messages | https://platform.claude.com/docs/en/models/opus-4-6/overview |
| AWS Bedrock (InvokeModel) | `anthropic.claude-opus-4-6-v1` |  | https://platform.claude.com/docs/en/build-with-claude/claude-on-amazon-bedrock-legacy |
| Google Cloud Vertex AI | `claude-opus-4-6` |  | https://platform.claude.com/docs/en/build-with-claude/claude-on-vertex-ai |
| Microsoft Foundry (Azure) | `claude-opus-4-6` |  | https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry |
| Claude Platform on AWS | `claude-opus-4-6` |  | https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws |
| OpenRouter | `anthropic/claude-opus-4.6` |  | https://openrouter.ai/anthropic/claude-opus-4.6 |
| Web app |  |  | https://claude.ai |

## Pricing

- Input: $5 per 1M tokens
- Output: $25 per 1M tokens
- Cache read: $0.50 per 1M tokens
- Unit as published: per 1M tokens (USD); Batch API 50% off
- Source: https://platform.claude.com/docs/en/about-claude/pricing
- Last checked: 2026-09-29

## Specs

- Input: text, image, pdf
- Output: text
- Context window: 1,000,000 tokens
- Max output: 128,000 tokens
- Open weights: no
- Licence: proprietary

## What it has not seen

- Published training cutoff: 2025-05 (May 2025).
- AI events after it on Post-Cutoff: 2,019 (467 major, 89 historic), as of 2026-11-13.
- Already missing at launch: 77.
- Briefings of the news since May 2025: https://postcutoff.com/briefings/cutoff-2025-05-s.md (short), https://postcutoff.com/briefings/cutoff-2025-05-m.md (medium), https://postcutoff.com/briefings/cutoff-2025-05.md (full).
- Its card, with five things it has never heard of: https://postcutoff.com/you/claude-opus-4-6/

## What stands out

- 1M-token context for Opus (first): First Opus with a 1M-token context window (launched in beta). Scored 76% on MRCR v2 long-context retrieval versus 18.5% for Sonnet 4.5. Source: https://www.anthropic.com/news/claude-opus-4-6
- Adaptive thinking (first): Introduced adaptive thinking: the model decides when and how much to think, steered by effort. Source: https://www.anthropic.com/news/claude-opus-4-6
- Agent teams (first): Research preview of multiple Claude instances coordinating in parallel (in Claude Code). Source: https://www.anthropic.com/news/claude-opus-4-6
- Knowledge work (GDPval-AA): About 144 Elo above GPT-5.2 on GDPval-AA. Also led Terminal-Bench 2.0 at launch. Source: https://www.anthropic.com/news/claude-opus-4-6

## Notes

First dateless-ID Opus; adaptive thinking (budget_tokens deprecated). Training data cutoff Aug 2025. Bedrock via InvokeModel only. Retirement not sooner than 2027-02-05.

Legacy Opus; migrate to `claude-opus-5-5`.

```bash
curl https://api.anthropic.com/v1/messages \
 -H "x-api-key: $ANTHROPIC_API_KEY" -H "anthropic-version: 2023-06-01" -H "content-type: application/json" \
 -d '{"model":"claude-opus-4-6","max_tokens":16000,"messages":[{"role":"user","content":"Hello"}]}'
```

Sources:
- Model page: https://platform.claude.com/docs/en/models/opus-4-6/overview
- Announcement: https://www.anthropic.com/news/claude-opus-4-6
- Pricing: https://platform.claude.com/docs/en/about-claude/pricing
- Models overview: https://platform.claude.com/docs/en/about-claude/models/overview
- Deprecations: https://platform.claude.com/docs/en/about-claude/model-deprecations

Model page: https://postcutoff.com/m/claude-opus-4-6/