Claude Opus 5 shipped on the 24th of July, 2026, as claude-opus-5. It's priced at $5 per million input tokens and $25 per million output tokens — the same as Opus 4.8, and half of what Fable 5 costs.

The context window is 1M tokens long, the max output is 128K. And there's one breaking change: the model thinks by default now. In other words, on...