Under the hoodTier: how much it should matter to you
3Useful: my rating, 1 to 5
4Signal: worth watching, 1 to 5
SDKArea: what it touches
Internal ChangesKind: in v2.1.292,
What probably matters to youSection of the release
What
The SDK is the kit that lets other apps drive Claude Code. When a background task finishes, it sends a notification. That notification can now carry two optional fields, handback and handback_report. They are used for subagents (helper agents Claude starts for part of a task) that report back through the SubagentHandback tool. Both fields are marked as internal.
Why
Apps built on the SDK can use these fields to show a subagent's report when its task completes.
