Anthropic’s Claude Fable 5.2 and Mythos 5.2 Reclaim the AI Performance Lead

What happened

The Decoder reports that Anthropic’s Claude Fable 5.2 and Mythos 5.2 reclaim the AI performance lead on several benchmarks, while Opus 5.5 remains the company’s recommended model for everyday use. Fable is available to all users with safeguards that block risky cybersecurity and biology tasks; Mythos removes some restrictions and is limited to organizations applying through Anthropic’s verification programs. Artificial Analysis places Fable 5.2 first on its current Index v5 at the highest compute tier, though the article notes weaker results in agentic knowledge work and terminal-based coding.

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The story so far

Anthropic released Claude Fable 5.2 and Claude Mythos 5.2, lowering API prices to $8 per million input tokens and $40 per million output tokens, from $10 and $50. Anthropic says both models improve coding, reasoning, and vision, and that Fable produces responses faster than version 5.1. Fable is available to paid users with safeguards for risky cybersecurity and biology tasks; Mythos is limited to organizations approved through Anthropic’s verification programs. The launch reports cite strong benchmark results, including Fable’s first-place score on Artificial Analysis’ Intelligence Index v5 at its highest compute tier. Those figures come from the named benchmark evaluations; Anthropic’s prerelease examples also include software migrations, electronic devices, and physics problems. TechCrunch reports that an optional faster serving mode costs twice as much, while the lower API prices apply to standard use.