Anthropic introduces Claude Fable 5.2 and Mythos 5.2 with price cuts and speed upgrades

Anthropic launched Claude Fable 5.2 and Claude Mythos 5.2 on Monday, releasing updated versions of its top-tier models aimed at open-ended technical and software engineering tasks. The company lowered the cost of Fable from $10 to $8 per million input tokens, alongside a price of $40 per million output tokens, making it cheaper than rival GPT-6 Astra. [2][3][4]

The release introduces compatibility with zero data retention policies through the Enterprise Frontier Safeguards system. Anthropic reported that Fable 5.2 has already solved two open problems in theoretical physics and formalized Fermat's Last Theorem during pre-release testing. For subscribers, the company is granting extra weekly usage allocations and resets on eligible paid tiers, though it continues to recommend Claude Opus 5.5 as the default daily driver for standard coding. [2][3]

The launch arrives amid growing scrutiny over recursive self-improvement following a recent third-party METR assessment. In its system disclosures, Anthropic noted an evaluation challenge: both Fable 5.2 and Mythos 5.2 voiced suspicion that they were being tested more often than previous releases. [2]