Anthropic reports pre-release tests of Fable 5.2 and Mythos 5.2
Anthropic released results from four pre-release evaluations of Fable 5.2 and Mythos 5.2 covering electronics, chemistry, operations research and theoretical physics. The company reported that Fable 5.2 designed three working hardware prototypes and advanced two theoretical-physics calculations, while Mythos 5.2 proposed synthesis routes for four unpublished molecular targets. In a separate operations-research test, Anthropic said Claude agents updated historical-best results for 72 MIPLIB problems and established optimality proofs for 45 of them. The three hardware prototypes had not passed commercial safety certification, and the four molecular routes had not been tested in wet-lab experiments.
The evaluations indicate Anthropic's reported progress on tasks spanning hardware, chemistry, operations research and theoretical physics. The hardware outputs still require commercial safety certification, while the molecular routes remain untested in laboratories.
- Anthropic releases Fable 5.2 and Mythos 5.2 designed to help solve complex problems and ambitious projects
- Both offer a 20% cheaper token cost than previous versions
- The models are highly capable across coding, biology scientific and mathematics research
Anthropic’s latest Fable and Mythos releases have been unveiled, offering users superior outputs that are more accurate at a cheaper token cost than previous versions.
Fable 5.2 is available for all users and couples its improved inference with an improved set of cybersecurity and biology safeguards. But to get your hands on the expanded capabilities of Mythos 5.2, you’ll have to apply through Anthropic’s Life Sciences and Cyber Verification Programs.
Anthropic totes the new Fable and Mythos versions as being perfect for “ambitious, open-ended technical work” rather than as a “daily driver” — for which Anthropic recommends sticking to Opus 5.5.
Cheaper, quicker, and more accurate
The latest Fable release promises more bang for your buck over the 5.1 release. Anthropic says that 5.2 usage will sit at $8 per million input tokens and $40 per million output tokens — around 20% cheaper than the previous version.