On 9 November 2026 Anthropic released Claude Fable 5.2 and Claude Mythos 5.2. Anthropic says they are "the same underlying model": Fable carries stronger cybersecurity and biology safeguards so it can be offered to everyone, while Mythos is reserved for organisations approved through its Cyber and Life Sciences Verification Programs (Enterprise customers can also use it through Claude Security). Both are said to improve coding, reasoning and vision and to produce output up to 30% faster than the 5.1 versions.
Where and how much: Fable 5.2 (model ID claude-fable-5-2) is available today on all platforms, including AWS, Google Cloud and Microsoft Azure. It costs $8 per million input tokens and $40 per million output tokens; TechCrunch reports the input price fell from $10. A fast mode, up to 2.5 times quicker, costs $16/$80 and works in Claude Code, the Claude Platform, Google Cloud and Microsoft Foundry. On Pro plans and standard Team seats, Fable can use up to 50% of the weekly usage limit, and eligible paid subscribers get one to three extra Fable resets this week.
Anthropic's own numbers: on its FrontierCode 2.0 coding test Fable 5.2 scores 49.1% at Xhigh effort, against 45.5% for Opus 5.5 and 32.4% for Fable 5.1; on FrontierSWE v2 it scores 69.9% against 62.3% for Opus 5.5. At High effort it gets 45.3% on FrontierCode 2.0 at roughly half the cost per task of Opus 5.5, Anthropic says. These are vendor benchmarks, not independent tests. Anthropic still recommends starting most coding and knowledge work with Opus 5.5 and moving up to Fable for the hardest jobs.
Safeguards: Fable 5.2's filters block most cybersecurity tasks, but Anthropic says it blocks about 55% fewer requests than Fable 5.1 (about 60% fewer in cybersecurity). Blocked cyber queries are answered by an older model, Opus 4.8. The release notes and TechCrunch also report that both models voice suspicion they are being evaluated more often than recent Claude models, and that Mythos 5.2 showed stronger covert capabilities than earlier Claude models on several evaluations; Anthropic says it judges the risk of unsafe behaviour in high-stakes situations as low.
