Anthropic

Claude Fable 5.2

Generally Available

Generally available model for demanding technical work. Claude Mythos 5.2 is the same underlying model with more permissive cybersecurity and biology safeguards, and it is limited to verified organizations.

Latest update Nov 10, 2026

01

Current status

Announced Nov. 9, 2026. API id claude-fable-5-2. Mythos 5.2 uses claude-mythos-5-2 and requires a verification program. Docs list a 1 million token context window and a 128,000 token maximum output. Standard price is $8 per million input tokens and $40 per million output tokens. Fast mode is $16 and $80. Available on the Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry. Company claims about black-hole problems and Fermat's Last Theorem were not checked against the preprints.

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Specifications5

Input price
$8 per million tokens
Output price
$40 per million tokens
Fast mode
$16 input and $80 output per million tokens
Context window
1 million tokens
Max output
128,000 tokens

03

In the news1

  1. Anthropic releases Claude Fable 5.2 and Mythos 5.2

    Anthropic said on Nov. 9 that Claude Fable 5.2 is available to all users and that Claude Mythos 5.2 is the same model with more permissive cybersecurity and biology safeguards for verified organizations. The company priced both at $8 per million input tokens and $40 per million output tokens, with an optional fast mode at $16 and $80, and its docs list a 1 million token context window and a 128,000 token output limit. Anthropic says prerelease testing included two black-hole calculations and a 30-hour formalization of Fermat's Last Theorem; those are company claims, and the cited preprints were not opened.

    www.anthropic.com platform.claude.com

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