I turned the Advent of Claude into a blog post where I could provide additional context, resources, and re-ordered the tips into a more logical order going from startup to advanced capabilities.
If you loved how Opus 4.6 felt to work with, Opus 5.5 feels like coming home. Same easy back-and-forth with a lot more horsepower underneath. It's the most fun I've had in Claude Code in a while.
It's also much cheaper (~40% less than Opus 5 on typical workloads).
In the Claude Code CLI's fullscreen mode /diff now opens a side panel listing every changed file with +/- line counts. It live-updates as Claude edits or runs commands, and you can select lines with your mouse to attach them to your next prompt.
Computer use in the Claude Code Desktop app now works in the background on Mac. Claude sees and acts in the apps you’ve approved while you keep working.
Background computer use is in beta on Pro and Max plans.