Claude Opus 4.6 is here. It was built with and mostly evaluated by Claude.

Their headline pitch includes:

1M token context window (in beta) with State of the art retrieval performance.
Improved abilities on a range of everyday work tasks. Model is improved.
State of the art on some evaluations, including Terminal-Bench 2.0, HLE and a very strong lead in GDPval-AA.
Claude Code now has an experimental feature called Agent Teams.
Claude Code with Opus 4.6 has a new fast (but actually expensive) mode.
Upgrades to Claude in Excel and the release of Claude in PowerPoint.

Other notes:

Price remains $5/$25, the same as Opus 4.5, unless you go ultra fast.
There is now a configurable ‘effort’ parameter with four settings.
Refusals for harmless requests with rich context are down to 0.04%.
Data sources are ‘all of the above,’ including the web crawler (that they insist won’t cross CAPTCHAs or password protected pages) and other public data, various non-public data sources, data from customers who opt-in to that and internally generated data. They use ‘several’ data filtering methods.
Thinking mode gives better [...]