New Delhi, July 25 -- SAN FRANCISCO - The Claude Opus lineup has had a gap since Sonnet 5 and Haiku 4.5 landed earlier this year. Anthropic filled it Thursday with Opus 5, a model it says outperforms Moonshot AI's Fable 5 on several benchmarks while charging half of Fable's per-token rate. That combination, cheaper and reportedly better than the current market leader, is the central claim Anthropic will spend the next few weeks defending as independent evaluations begin.

Pricing lands at $5 per million input tokens and $25 per million output tokens, identical to what Opus 4.8 cost when it launched two months ago. Fable 5 runs at roughly double that. For organizations that have been routing tasks between Fable 5 and less capable Claude mo...