You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
SandboxArea: what it touches
ImprovementsKind: in v2.1.307,
ImprovementsSection of the release
What
On Windows, /sandbox install sets up the sandbox, a restricted environment Claude Code runs commands in, under its own Windows user. Set-up now does more:
It detects when the Windows secondary logon service, which lets programs run as another user, cannot be used, and reports a partial result saying "Set-up changed nothing" and to run it again once this is fixed.
After a successful install, it starts the sandbox user for the first time and waits up to 150 seconds.
It then adds a note saying whether Windows signed the user in, timed out, did not start it, or ran out of time. If sign-in fails, Claude Code tries again the next time it starts the sandbox.
Running /sandbox uninstall inside a session is now refused. It tells you to close every Claude Code session and run claude sandbox uninstall in a terminal. The old hint pointing to npx @anthropic-ai/sandbox-runtime windows-uninstall is gone.
Why
Windows users learn during set-up when the sandbox will not work, and why, instead of finding out later.
