What
The sandbox limits what commands Claude runs can touch, and /sandbox lets you change its settings. When Claude Code saves those settings, it now checks whether the save worked. If it did not, it records a failed save. Before, the result was ignored and the save was always recorded as a success.
Why
A sandbox settings change that did not actually get saved is no longer quietly treated as saved.
Names in the bundle/sandbox
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on Claude apps gateway configuration touched a line naming /sandbox after this was published.
* The egress allowlist, from `sandbox.network.allowedDomains`. If you set `coworkEgressAllowedHosts` in the policy's `desktop` block, the gateway uses that value instead of the derived list. If the allowlist the gateway serves includes `*`…claude-apps-gateway-config see the edit
Confirmed since
Anthropic's documentation has since written up /sandbox, on Error reference.
* To sandbox the sessions the server starts, turn on [sandboxing](/docs/en/sandboxing) by setting [`sandbox.enabled`](/docs/en/settings-reference#sandbox-enabled) to `true` in a [settings file](/docs/en/settings#where-settings-live)errors see the edit
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up /sandbox, on Error reference.
Anthropic's release notes agree
Fixed /sandbox reporting success when its setting could not be saved because the project folder is not writable; it now says nothing changed…