Anthropic launches Claude Fable 5.2 and Mythos 5.2: 30% faster, 20% cheaper

Anthropic shipped two models on November 9. Fable 5.2 is its most capable generally available model for technical work. Mythos 5.2 offers restricted advanced capabilities through Anthropic's Cyber Verification Program and related verification schemes, with hardened enterprise and biosecurity safeguards. Both generate responses up to 30% faster than 5.1 on complex coding tasks. Pricing drops 20% to $8/M input and $40/M output tokens, which CNBC and others framed as undercutting OpenAI's GPT-6 Astra.

Anthropic cited prerelease results including formalizing Fermat's Last Theorem in about 30 hours and completing software migrations previously judged infeasible. On Artificial Analysis, Fable 5.2 scored 65, the top score on the index to date. Ethan Mollick, who had early access, wrote that it "crosses the line into being a sort of Jagged AGI", showing it launching a business, doing academic research and hacking hardware. Perplexity's Aravind Srinivas added it to Computer and claimed it beats Gemini Argon on wide and deep research tasks.

Distribution was immediate: the models went live on Amazon Bedrock, Claude Platform on AWS and AWS GovCloud the same day. The launch is also Anthropic's first frontier release since Dario Amodei called for an industry slowdown, an optics question developers raised loudly, and it lands days before a planned IPO.

Skeptics exist. HN commenters say the speedup over Opus 5.5 is hard to notice on ordinary coding and only shows on ambitious projects, and an r/Anthropic thread asking "is Opus 5.5 nerfed?" (726 upvotes) fed suspicions that the older model was degraded before launch. Independent benchmarks over the coming weeks will test the claims.