Anthropic ships Opus 5.5 with cache-read prices cut 60%
Both major labs cut frontier prices the same day; cache cost falls hardest for long-context agents, while performance numbers remain vendor-reported.
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Anthropic released Claude Opus 5.5 on September 22, cutting input to $4 per million tokens and output to $20, with cache reads down 60% to 20 cents; the faster serving mode runs $8 and $40.
The model is live on the Claude Developer Platform and on AWS, Google Cloud and Azure, with Sonnet 5.5 and Haiku 5.5 due in coming weeks. OpenAI released GPT-6 Sol and Luna at half price the same day, so the frontier price war moved at both labs at once.
Benchmark figures such as 66.4% on Terminal-Bench 4.0 are Anthropic's own, with no third-party verification yet; for teams running long-session agents, the cache price cut is the most certain cost change available today.