Claude Mythos 5.1
Open in the interactive archive →
Overview
Same weights as Claude Fable 5.1 but with some safeguards lifted for approved frontier red-team and enterprise partners under Project Glasswing. Terminal-Bench 4.0: 60.9%.
Generates
PDF generationSpreadsheet generation
Details
- Vendor
- Anthropic
- Type
- LLM
- Release year
- 2026
- Jurisdiction
- USA
- CEO
- Dario Amodei
- Key staffers
- Daniela Amodei (President & Co-Founder), Jack Clark (Co-Founder, Policy), Tom Brown (Co-Founder), Sam McCandlish (Co-Founder), Jared Kaplan (Co-Founder, Chief Science Officer), Mike Krieger (Labs), Paul Smith (CCO)
- Deployment
- Cloud (restricted; Project Glasswing participants only)
- Open source
- No
- Free tier
- No
- Subscription
- Restricted access via Anthropic's Project Glasswing (CVP/LSVP participants); per-token rate not published.
- Stock status
- Private ($380B valuation, Feb 2026); confidentially filed for IPO Jun 1, 2026
- X
- @AnthropicAI
Known safety issues
Deliberately relaxed safeguards in some domains; access restricted to vetted Glasswing participants.
AIDb Rating
AIDb v2.0 (curated): Capability 9/10 · Currency 10/10 · Access 2/10 · Significance 6/10 → 6.75
Last verified 2026-09-14 · Primary source ↗
Cite this
“Claude Mythos 5.1.” AIDb — The AI Database. Verified 2026-09-14. https://theaidatabase.com/m/anthropic-claude-mythos-5-1.html
More from Anthropic
Claude · Claude 2 · Claude 2.1 · Claude 3 · Claude 3 Haiku · Claude 3 Opus · Claude 3 Sonnet · Claude 3.5