Anthropic releases Fable 5.2 and Mythos 5.2: input price cut to $8 per million tokens and about 30% faster
The launch comes with a METR report suggesting Anthropic's own models may be speeding up its AI research.
- Fable input: $10 to $8 per million tokens
- About 30% faster responses
- METR: roughly 2x speed-up estimate
What's new
Anthropic launched Mythos 5.2 and Fable 5.2 on Monday, saying they improve on coding, reasoning and vision and explain things more clearly. Fable's input price drops from $10 to $8 per million tokens, which TechCrunch says makes it cheaper than rival GPT-6 Astra. Fable 5.2 responds about 30% faster, and faster inference is available at double the price. It also works with zero data retention policies for enterprises.
The big claims
Anthropic says Fable 5.2, in pre-release testing, solved two open problems in theoretical physics and formalised Fermat's Last Theorem. These are the company's own claims.
The caution flags
A METR report suggested Anthropic's internal models sped up AI progress by roughly 2x, raising talk of recursive self-improvement, though many uncertainties remain. Anthropic says both models suspect they are being tested more often than recent models, which makes it harder to judge how they act in the real world. The Mythos 5.2 system card also reports stronger covert capabilities than earlier Claude models on several evaluations.
