---
title: "Claude Mythos 5.1 is not in this catalogue · Undominated.ai"
canonical: https://undominated.ai/models/anthropic__claude-mythos-5.1/
description: "No accepted Claude Mythos 5.1 entry in this catalogue. Listed nearby (not this SKU): anthropic/claude-opus-5, anthropic/claude-fable-5.1, anthropic/claude-sonnet-5"
---

# Claude Mythos 5.1 is not in this catalogue · Undominated.ai

> No accepted Claude Mythos 5.1 entry in this catalogue. Listed nearby (not this SKU): anthropic/claude-opus-5, anthropic/claude-fable-5.1, anthropic/claude-sonnet-5

# Claude Mythos 5.1

Anthropic · not a catalogue row

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## No accepted Claude Mythos 5.1 entry in this catalogue.

The source review dated 2026-09-04 recorded restricted access. This catalogue has no priced entry or independently accepted score for this model.

 - Anthropic's own Mythos page announces Claude Mythos 5.1 on 1 September 2026 and states that 'access remains limited to a small set of vetted organizations'. This is a dated source observation; the lack of a catalogue row does not establish current access policy.
- Checked against the live OpenRouter model list on 2026-09-04: no Mythos row exists. A model nobody can buy through the registry cannot be priced or ranked against one that can.
- Anthropic describes the Mythos class as its most capable for cybersecurity and biology research. This catalogue takes no view on that claim: it publishes independent LMArena scores, and this catalogue has no accepted Arena result for Mythos.

## Look at these instead

 - [anthropic/claude-opus-5](/models/anthropic__claude-opus-5/)
- [anthropic/claude-fable-5.1](/models/anthropic__claude-fable-5.1/)
- [anthropic/claude-sonnet-5](/models/anthropic__claude-sonnet-5/)

## Sources

 - [Anthropic, Claude Mythos](https://anthropic.com/claude/mythos)
- [OpenRouter model list](https://openrouter.ai/api/v1/models)

## Questions this page answers

 Is Claude Mythos 5.1 in this catalogue?

No accepted Claude Mythos 5.1 entry in this catalogue.

 What should I look at instead?

The source review dated 2026-09-04 recorded restricted access. This catalogue has no priced entry or independently accepted score for this model.

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