Anthropic released Claude Fable 5.2 and Claude Mythos 5.2 on November 9. The new models are designed for coding, research, engineering, and cybersecurity work. Anthropic says they improve coding, reasoning, and vision while communicating more clearly than earlier versions.
Fable 5.2 cuts costs
The models also improve speed and pricing. Anthropic says they generate outputs up to 30% faster than Fable 5.1 and Mythos 5.1. Standard pricing is $8 per million input tokens and $40 per million output tokens. That is lower than the previous Fable model's $10 input-token price, according to TechCrunch and Anthropic.
Anthropic also offers an optional fast mode. It can increase token-generation speed by up to 2.5 times and costs $16 per million input tokens and $80 per million output tokens.
Mythos targets high-risk work
The two models are aimed at different users. Fable 5.2 is the general-use version and includes safeguards for high-risk cybersecurity and biology tasks. Mythos 5.2 uses the same underlying model but is available to approved organizations through Anthropic's Cyber Verification and Life Sciences Verification programs.
Anthropic says Mythos 5.2 found more vulnerabilities than earlier models in internal testing. The company also says Fable 5.2 helped complete difficult software migrations, design electronic devices, and coordinate more than 1,000 agents to build a working operating system during an internal experiment. Anthropic reported these results.
Models reach cloud platforms
Fable 5.2 is available on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure. Developers can access it through Anthropic's Claude Platform. Anthropic says fast mode is also available on Claude Code, Google Cloud, and Microsoft Foundry.
The release includes benchmark results and a system card that describes the models' performance, safeguards, and remaining limitations. Those materials provide the main details about how Anthropic evaluated the new systems and where access to Mythos remains limited.
References
Brandom, R. (2026, November 9). Anthropic releases new Mythos and Fable models amid RSI concerns. TechCrunch. https://techcrunch.com/2026/11/09/anthropic-releases-new-mythos-and-fable-models-amid-rsi-concerns/
Anthropic. (2026, November 9). Introducing Claude Fable 5.2 and Claude Mythos 5.2. https://www.anthropic.com/claude-fable-and-mythos-5-2