A Windows managed sandbox CA, installed via /sandbox install, sits behind CLAUDE_CODE_NANKEEN_KESTREL, off by default.
CA resolution for sandbox.network.tlsTerminate was reworked, and on Windows a persistent sandbox-managed CA can be used instead of an ephemeral one, though that path is switched off in this build.
- Three CA sources now exist: a trusted caCertPath/caKeyPath pair from settings, a "managed" CA, or unavailable, with a certificate-thumbprint check that reads the managed CA cert from disk.
- On native Windows an ephemeral CA cannot pass the sandbox trust check; the managed CA is set up via
/sandbox install, and the settings description documents this. - Trust failures now throw typed errors carrying codes rather than plain Error objects.
- The old refusal message about missing caCertPath/caKeyPath is replaced by one saying the managed CA is gated off.
- The managed-CA path is Windows-only and gated on CLAUDE_CODE_NANKEEN_KESTREL, else
tengu_nankeen_kestrelwith an in-source fallback of false, so it is disabled by default here.
On native Windows an ephemeral CA cannot pass the sandbox trust check, [sandbox] settings tlsTerminate has no CA paths and the managed sandbox CA is gated off on Windows
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 v2.1.221: 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 v2.1.221. It isn't a statement about your account. What a flag value here can and cannot tell you