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-4-1/

# Claude Opus 4.1

Anthropic, Claude 4 family. Status: retired. Type: reasoning model. Released: 2025-08-05. Training cutoff: not published.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| Anthropic API (Claude API) | `claude-opus-4-1-20250805` | https://api.anthropic.com/v1/messages | https://platform.claude.com/docs/en/about-claude/model-deprecations |
| OpenRouter | `anthropic/claude-opus-4.1` |  | https://openrouter.ai/anthropic/claude-opus-4.1 |

## Pricing

- Input: $15 per 1M tokens
- Output: $75 per 1M tokens
- Unit as published: per 1M tokens (USD), Bedrock/Google Cloud may differ
- Source: https://platform.claude.com/docs/en/about-claude/pricing
- Last checked: 2026-09-29

## Specs

- Input: text, image, pdf
- Output: text
- Context window: 200,000 tokens
- Max output: not published
- Open weights: no
- Licence: proprietary

## What it has not seen

- No published training cutoff. Counted from its release (2025-08-05): at least 2,007 AI events since (463 major, 88 historic), as of 2026-11-13.
- Everything since July 2025: https://postcutoff.com/since/2025-07/

## What stands out

- SOTA SWE-bench Verified (Aug 2025): 74.5% on SWE-bench Verified at launch. Source: https://www.anthropic.com/news/claude-opus-4-1
- Precise multi-file refactoring: GitHub and Rakuten highlighted multi-file refactoring and pinpoint fixes without unnecessary changes. Source: https://www.anthropic.com/news/claude-opus-4-1

## Notes

Retired on the Claude API 2026-08-05 (replacement claude-opus-4-8 / claude-opus-5-5); still available on Amazon Bedrock and Google Cloud per Anthropic pricing page. Cloud ids not re-verified today.

Retired on Anthropic-operated platforms; requests to `claude-opus-4-1-20250805` on the Claude API fail. Listed for reference because it may still be reachable via Bedrock, Google Cloud or OpenRouter.

Sources: https://platform.claude.com/docs/en/about-claude/model-deprecations , https://platform.claude.com/docs/en/about-claude/pricing

Model page: https://postcutoff.com/m/claude-opus-4-1/