Key Info

Claude Opus 5.5, the first model in Anthropic's Claude 5.5 family, is now live on OpenRouter, leading Opus 5 and Fable 5.1 on agentic coding, knowledge work, and computer use.

Highlights

  • 1M context at $4/M input and $20/M output, 20% lower per token than Opus 5.
  • Costs 40% less than Opus 5 to run on typical workloads at default settings and generates output over 30% faster.
  • Migration notes: adaptive-only thinking, forced tool use retired; OpenRouter provides guidance on updating prompts.