Windows sandbox support now includes a full one-time install flow that sets up a dedicated sandbox user and WFP (Windows Filtering Platform) network filters.
/sandbox install # install sandbox user and WFP network filters
/sandbox # check current sandbox status- Requires administrator privileges for the initial install (an elevation prompt appears).
- After install:
Sandbox user and network filters installed— confirmed via/sandbox. - If the elevation prompt was missed: re-run
/sandbox installand approve within a minute. - WFP filter installation is idempotent; passing
force: truereplaces existing filters if the port range or sandbox user name changed. - New error classes:
SandboxCommandTooLongError(command too long for the OS argv limit — write to a file instead),SandboxPolicyRefusalError(enterprise policy blocks the command),SandboxUnavailableForShellError(shell not sandboxable). - PowerShell commands on Windows are labeled
PowerShell command (unsandboxed)to clarify they bypass the sandbox. - Feature-gated via
tengu_nankeen_kestrel.
"Windows sandbox needs a one-time install." (search for "srt-win install" and "ClaudeCodeSandbox")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_nankeen_kestrel Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.212: off
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.212. It isn't a statement about your account. What a flag value here can and cannot tell you
New in this build: tengu_nankeen_kestrel