Claude Opus 5: Release Date, What We Know & Full Claude Model Guide
There is no Claude Opus 5. Anthropic introduced Fable 5 as a Mythos-class model above Opus. This guide covers the full 2026 Claude lineup — Fable 5, Opus 4.8, Sonnet 5, Haiku 4.5 — with pricing, benchmarks, and a decision framework.