Anthropic Launches Claude Fable 5 and Mythos 5 AI Models

Claude Fable 5 is a new state-of-the-art model designed for general use, showing exceptional performance in software engineering, knowledge work, vision, and scientific research. It features conservative safeguards that redirect certain sensitive queries to a less capable model, impacting less than 5% of sessions.

Claude Mythos 5, based on the Fable 5 model but with lifted safeguards, is initially available through Project Glasswing for cybersecurity applications. It offers the world's strongest cybersecurity capabilities and will soon expand access through a broader trusted program.

Fable 5 has shown impressive results in software engineering, compressing months of work into days and performing complex code migrations. It also leads in knowledge work, excelling in complex analytical tasks, document-based reasoning, and financial analysis benchmarks.

Fable 5 sets a new standard for vision tasks, extracting precise data from scientific figures and rebuilding web apps from screenshots. It also maintains focus across millions of tokens in long-running tasks and improves outputs using its own notes, showing significant gains in memory and context handling.

In life sciences, Mythos 5 has accelerated aspects of drug design by approximately 10 times and consistently produces novel, compelling scientific hypotheses in molecular biology. It has also conducted novel genomics research autonomously, outperforming previously published models.

Claude Fable 5 and Mythos 5 are priced at $10 per million input tokens and $50 per million output tokens, which is less than half the price of Claude Mythos Preview. Access for Fable 5 is general, while Mythos 5 is initially restricted.