Claude Mythos 5.1
Anthropic · not a catalogue row
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.
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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.