What's new for you
### Changes - Agents/Anthropic: add opt-in 1M context beta header support for Opus/Sonnet via model `params.context1m: true` (maps to `anthropic-beta: context-1m-2025-08-07`). - Agents/Models: support Anthropic Sonnet 4.6 (`anthropic/claude-sonnet-4-6`) across aliases/defaults with forward-compat fallback when upstream catalogs still only expose Sonnet 4.5. - Commands/Subagents: add `/subagents spawn` for deterministic subagent activation from chat commands. (#18218) Thanks @JoshuaLelon. -…
Full release notes
The complete changelog with all changes, fixes, and technical details is on the official GitHub release page.
Open v2026.2.17 on GitHub →