Claude Opus 5.5 scores 58 on the Artificial Analysis Intelligence Index at max effort — highest measured by several points. Brings Anthropic to parity with GPT-6 Astra on Terminal-Bench 4.0 and AutomationBench-AA.
Pricing: 20 input/output per MTok (down from 25). Cache reads discounted to $0.20/MTok (60% reduction).