Under the hoodTier: how much it should matter to you
1Useful: my rating, 1 to 5
0Signal: worth watching, 1 to 5
SDKArea: what it touches
Internal ChangesKind: in v2.1.281,
Internal ChangesSection of the release
What
Apps that embed Claude Code through its SDK (software development kit) send it control requests. The replies (control_response, either success or error) are now built by one shared helper. Unknown request types all raise the same message, "unsupported control_request subtype".
Why
Apps built on the SDK should see a consistent error when they send a request type Claude Code does not support.
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtThe finding does not show whether replies look any different to an SDK app than they did before.
