Anthropic released Claude Opus 4.6 with a 1-million-token context window and support for agent teams — multiple coordinated sub-agents working under one orchestrator. Claude Sonnet 4.6 followed on February 17 as the everyday workhorse tier.

The 1M context put Claude on par with the longest-context rivals, and agent teams formalized the multi-agent patterns developers had been hand-rolling. Anthropic framed the release around autonomous teams rather than single agents.

Opus 4.6 held the flagship slot through the first half of 2026, until the Fable line and Opus 5 arrived later in the year.