# Claude Mythos 5

Claude Mythos 5 is a model from Anthropic, first recorded on 7 Oct 2026; its release date is not established. The context window is 1,000,000 tokens. The maximum output is 128,000 tokens. Pricing is $10.00 per million input tokens and $50.00 per million output tokens.

- Developer: Anthropic
- Id: claude-mythos-5
- Reported: 2026-07-01T13:44:59.000Z
- Sighting: 2026-10-07T19:43:10.391Z
  - [evidence link](https://code.claude.com/docs/en/changelog)
- Status: Sighting
- Canonical: https://alexgetman.com/models/anthropic/claude-mythos-5/

## Questions

### What is the context window of Claude Mythos 5?

The context window is 1,000,000 tokens. The maximum output is 128,000 tokens.

### How much does Claude Mythos 5 cost?

Pricing is $10.00 per million input tokens and $50.00 per million output tokens. Cached input is $1.00 per million.

### When was Claude Mythos 5 released?

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

## Timeline

- 2026-07-01T13:44:59.000Z · [Alex Getman](https://alexgetman.com/21/claude-fable-is-back/)
> Claude Fable is back!
> 
> Anthropic has lifted restrictions on Claude Fable 5 and Mythos 5 after a decision by the US government.
> 
> Fable will be available to Claude users again starting today.
> 
> Until July 7, the model is included in weekly limits. After that, access will move to API.
> 
> The restriction started after an Amazon report: researchers found a way to bypass Fable’s safeguards in cybersecurity tasks.
> 
> Anthropic says the bypass did not unlock Mythos-level capabilities. The company has already added a new safety classifier that blocks this method in more than 99% of cases.
> 
> Anthropic is also preparing a common standard for evaluating AI jailbreaks.
- 2026-07-24T18:30:37.661Z · [Alex Getman](https://alexgetman.com/110/be-like-dario-amodei/)
> Be like Dario Amodei
> 
> > Spend months warning everyone about Mythos 5
> 
> > Then release a nerfed version called Fable 5
> 
> > Send everyone into a panic
> 
> > Then start wondering whether to shut the model down entirely
> 
> > A couple of weeks later, drop Opus 5
> 
> > Which beats Fable at half the price
- 2026-10-07T19:43:10.391Z · [Claude Code · changelog](https://code.claude.com/docs/en/changelog)
- 2026-11-13T17:22:56.107Z · [Anthropic · official articles](https://www.anthropic.com/news/claude-opus-5)
- 2026-11-13T20:13:42.616Z · [Anthropic · official articles](https://www.anthropic.com/news/improving-alignment-security-efforts)

## Evidence links

- [editorial](https://alexgetman.com/110/be-like-dario-amodei/)
- [editorial](https://alexgetman.com/21/claude-fable-is-back/)
- [claude-code-changelog](https://code.claude.com/docs/en/changelog)
- [anthropic-pricing](https://platform.claude.com/docs/en/about-claude/pricing)
- [anthropic-model-index](https://platform.claude.com/docs/en/models/mythos-5/overview)
- [anthropic-articles](https://www.anthropic.com/news/claude-opus-5)
- [anthropic-articles](https://www.anthropic.com/news/improving-alignment-security-efforts)

## Signals