Anthropic Launches Strongest AI Models Claude Fable 5/Mythos 5

Anthropic has launched its strongest Claude model, Claude Fable 5, which comprehensively surpasses previous generations and leads significantly in benchmarks such as SWE-Bench Pro. The model can complete the migration of a 50 million-line codebase within 1 day and offers higher token efficiency. Anthropic has also launched the ungated version, Claude Mythos 5, available only to Glasswing partners. Claude Fable 5 is equipped with safety guardrails, and sensitive requests are downgraded to Claude Opus 4.8.

Claude is an artificial intelligence, trained by Anthropic using Constitutional AI to be safe, accurate, and secure — the trusted assistant for you to do your best work.

April 9, 2025 • This article tells the story of several founders who left OpenAI, bringing with them the concept that "AI must be ethical," to found the company Anthropic, and cultivated (as they say) "the most upright citizen in the AI world," Claude.

June 9, 2026 Anthropic released Claude Fable 5, positioned as the public safety version of the Mythos-level model, officially claiming that in almost all bas...

2 days ago • Claude is a family of large language models developed by the US artificial intelligence company Anthropic, with the first version released on March 15, 2023. The founding team includes former core members of OpenAI and GPT-3 developers. The model uses the Constitutional AI training method, support...

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