Anthropic Launches Claude Fable 5.2 and Mythos 5.2 on November 9: Standard Pricing of $8 per Million Input Tokens and $40 per Million Output Tokens, With Output Generation Up to 30 Percent Faster
Anthropic released its new models Claude Fable 5.2 and Claude Mythos 5.2 on November 9, 2026. The company said the two are configurations of the same underlying model: Fable 5.2 is the generally available version, carrying strong safeguards against misuse in cybersecurity and biology, while Mythos 5.2 relaxes some of those safeguards and is limited to vetted organizations.
According to Anthropic, Fable 5.2 is available in Claude paid plans, Claude Code, the Claude Platform, and on Amazon Web Services, Google Cloud and Microsoft Azure, under the developer model identifier claude-fable-5-2. Direct access to Mythos 5.2 is limited to organizations approved through Anthropic's Cyber Verification Program or Life Sciences Verification Program, and Claude Enterprise customers can also reach Mythos through Claude Security, which scans codebases for vulnerabilities.
Both models carry standard application programming interface pricing of $8 per million input tokens and $40 per million output tokens, down from $10 and $50 for Fable 5.1 and Mythos 5.1. An optional fast mode costs $16 per million input tokens and $80 per million output tokens and, the company said, can increase token generation speed by up to 2.5 times.
Anthropic said the 5.2 models generate output up to 30 percent faster than the 5.1 versions and communicate more clearly. Platform documentation lists a context window of 1 million tokens for Fable 5.2, a maximum output of 128,000 tokens, and a knowledge cutoff of June 2026, with text and image input and text output. In the company's published FrontierCode 2.0 evaluation, Fable 5.2 scored 49.1 percent at Xhigh effort, against 32.4 percent for Fable 5.1. In an October 2026 vulnerability rediscovery evaluation covering 1,829 published vulnerabilities, Mythos 5.2 scored 89.6 percent, against 78.3 percent for Mythos 5.1. The figures are the company's own published test results.
Anthropic also said that during prerelease testing Fable 5.2 helped address two open problems in black hole physics, with preprints posted for both results, and that a run of 1,000 Fable 5.2 agents formalized a proof of Fermat's Last Theorem in Lean in 30 hours. The company said Fable 5.2's safeguards are as robust as those in 5.1, with about 55 percent fewer unnecessary safeguard blocks in early testing, including about 60 percent fewer in cybersecurity and 40 percent fewer in biology. Anthropic continues to recommend Claude Opus 5.5 as the starting point for most everyday coding and knowledge work, with Fable and Mythos positioned for the most ambitious, open ended technical work. Reuters reported the same day that the launch comes as Anthropic prepares for a planned initial public offering amid intensifying competition with OpenAI.
来源链接
https://www.reuters.com/technology/anthropic-unveils-new-fable-mythos-models-competition-heats-up-ahead-ipo-2026-11-09/ （路透社2026年11月9日报道，数据与 Anthropic 当日发布口径一致）
https://www.securities.io/anthropic-launches-claude-fable-and-mythos-5-2-at-lower-api-prices/ （Anthropic 发布细节与平台文档数据汇总）
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Source: 路透社
Published by GSM · USA (original Chinese edition)
Photo: Wikipedia/Wikimedia Commons 词条主图：Anthropic
