# Claude Mythos 5.1

Claude Mythos 5.1 · Not on the active radar. A release or rename under this name is not confirmed.

- Developer: Anthropic
- Id: claude-mythos-5-1
- Reported: 2026-09-15T00:00:00.000Z
- Sighting: 2026-10-07T19:48:07.450Z
  - [evidence link](https://platform.claude.com/docs/en/about-claude/pricing)
- Status: Sighting
- Not on the active radar. A release or rename under this name is not confirmed.
- Canonical: https://alexgetman.com/models/anthropic/claude-mythos-5-1/

## Questions

### How much does Claude Mythos 5.1 cost?

Pricing is $10.00 per million input tokens and $50.00 per million output tokens. Cached input is $0.25 per million.

### When was Claude Mythos 5.1 released?

Its release date is not established. Signal Forge first recorded it on 7 Oct 2026.

## Timeline

- 2026-11-13T17:12:46.898Z · [Anthropic · official articles](https://www.anthropic.com/claude-fable-and-mythos-5-1)
**Confirmed use**
- 2026-11-13T17:12:46.898Z · [Anthropic · official articles · Introducing Claude Mythos and Fable 5.1](https://www.anthropic.com/claude-fable-and-mythos-5-1)
- 2026-11-13T17:43:43.996Z · [Anthropic · official articles](https://www.anthropic.com/news/cyber-verification-program)

## Evidence links

- [anthropic-pricing](https://platform.claude.com/docs/en/about-claude/pricing)
- [anthropic-model-index](https://platform.claude.com/docs/en/models/mythos-5-1/overview)
- [anthropic-articles](https://www.anthropic.com/claude-fable-and-mythos-5-1)
- [anthropic-articles](https://www.anthropic.com/news/cyber-verification-program)

## Signals