Anthropic is launching Claude Opus 5.5, the first model in a new family. The company says it delivers Claude Fable 5.1-level performance while costing significantly less and running faster than its predecessor. According to Anthropic, Opus 5.5 matches Claude Fable 5.1 "on most tasks" while costing about 40 percent less to run than Opus 5. Claude Sonnet 5.5 and Haiku 5.5 are expected in the coming weeks, with similar gains in performance, efficiency, and safety. Anthropic's benchmarks show the ne...