Claude Opus 5.5 is generally available today, September 22, at $4/$20 per million tokens, leading the Opus tier with a 1M-token context window and what Anthropic positions as a step forward in agentic coding.

It arrives three weeks after the Mythos-class Fable 5.1 (September 1, $10/$50, GA day one) and a day after xAI's Grok 4.7 (September 21, $2/$6, 500K context, a new larger base at Grok 4.6's price). Add DeepSeek V4.1-Flash's MIT weights on September 10 and Gemini 3.8 Flash on September 2, and September 2026 is the densest flagship month of the year.

Why Opus 5.5 matters most to builders

The Opus tier is where coding agents actually get deployed at scale. A 1M context with tier-leading agentic coding results makes Opus 5.5 the reference other labs' autumn releases will be measured against, including, in our October 22 showdown review, GPT-6 Astra at 2.5x the price.

Anthropic's current pricing page lists Opus 5.5 at $4/$20 per million tokens. Earlier versions of this story quoted $5/$25, which does not appear on that page.

Sonnet 5.5 follows on September 28 at $2/$10. The Claude family takes an Adopt Now badge in the Model Guide.