What probably matters to youSection of the release
What
Hooks gained a DirectoryAdded event that fires after a working directory is registered mid-session, so you can react to /add-dir and to SDK-driven directory registration.
Details
Described in the hook config as "After a working directory is added mid-session"; fires after the directory is registered and after the sandbox config is refreshed.
Hook input JSON carries the absolute directory and a source; the matcher can match on "slash_command" for /add-dir and "register_repo_root" for the SDK control request.
Registered in the hook config schema, the hook registry, the SDK hook-event enum and the /hooks UI.
Failure handling differs by path: for /add-dir a failure count is summarised to Claude and hook systemMessage output reaches Claude; for register_repo_root failures are debug-logged only, via "DirectoryAdded hook failed: ".
Evidence
"slash_command" for /add-dir, "register_repo_root" for the SDK control_request., After a working directory is added mid-session
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeAdded DirectoryAdded hook that fires after /add-dir or the SDK register_repo_root control request registers a new working directory…
