A leak claims Anthropic’s next model, Claude Opus 5.5, is in private testing under the codename claude-wafer-eap and expected on Tuesday, September 22 at $4 per million input tokens and $20 per million output tokens, or 20% below Claude Opus 5. The leak also lists cache reads at $0.20 and cache writes at $5 per million tokens, implying a 60% cut on cache reads, which today cost $0.50 on Opus 5. Anthropic, led by Dario Amodei, has confirmed nothing, and Opus 5.5 does not appear on its news page, whose latest announcement is dated September 18, a partnership with Accenture on evaluations. The claim began with a post by developer Lyra (@lyraxana on X), published between the weekend and Monday morning, September 21, amplified by @kimmonismus and picked up by 36Kr, Tencent News, TheWinCentral and KuCoin. Performance claims are anecdotal: tester Harshith says Opus 5.5 beats Fable 5.1 and Astra, citing a 3D Waymo model generated by Claude Code’s max mode, while tester Veee describes better Web3D car rendering. Outlets add progress in code, long-running agents and Three.js 3D graphics, without a public benchmark. A circulating session figure lists 1,400