Anthropic

Anthropic's most capable model is not on general sale. On 9 June 2026 the company announced Claude Fable 5 and Claude Mythos 5 in a single post, calling them "a tier of Claude models that sit above our Opus class in capability" — and describing them as the same underlying model, separated only by which safeguards are switched on. Fable 5 shipped everywhere. Mythos 5 went to Project Glasswing partners with cyber safeguards lifted; select biology researchers, with biology and chemistry safeguards lifted, are still listed as coming. The distinction between the model anyone can buy and the model almost nobody can is a policy setting, not a checkpoint.

Three days later both were withdrawn. The same announcement page carries a 12 June note — "We are suspending access to Claude Fable 5 and Claude Mythos 5" — and a 1 July note saying they were available again. The Mythos page is more specific about what changed in between: access was restored "for a set of US organizations, following the US government's approval." A frontier tier was off the market for nineteen days and came back through a clearance rather than a deploy.

Below that line, the price ladder has been remarkably still. Every Claude Opus release since anthropic/claude-opus-4.5, listed 24 November 2025, carries the same list price in the OpenRouter catalog — five releases (claude-opus-4.5, -4.6, -4.7, -4.8, claude-opus-5) over nine months at $5.00per million tokensopenrouter-models, last checked 2026-09-24 and $25.00per million tokensopenrouter-models, last checked 2026-09-24. Anthropic said as much when it shipped Opus 5: improved performance "for the same cost as its predecessor."

What moved instead was the window. The listed context window quintupled at anthropic/claude-opus-4.6 on 4 February 2026 — up from the 200000tokensopenrouter-models, last checked 2026-09-24 of the November row — and every release since carries the 1000000tokensopenrouter-models, last checked 2026-09-24 this one does. Five times the context, at a list price that never moved.