Anthropic reports Fable 5.2 benchmark gains

Anthropic shared benchmark results for Fable 5.2, showing that a swarm of 1,000 agents formalized Fermat's Last Theorem in 30 hours while Opus 5.5 flatlined at 27 percent. According to the test results, Fable 5.2 also autonomously solved a 23-year-old black hole physics calculation and designed three working hardware circuit boards that booted on the first try. Open article →