What
Some sessions are bound to a single computer and accept messages only from it or from a trusted device. When a message is refused for that reason, the advice now reads: "this machine could not prove it is the computer the session is bound to, or a trusted device; run /login to enroll it".
It still points you to /login to sign in and add the machine.
Why
The error now says what went wrong on your machine, not only the rule the session follows.
Names in the bundle/login
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 for Amazon Bedrock, Claude Platform on AWS, Google Cloud, and Microsoft Foundry touched a line naming /login after this was published.
Some organizations number their internal network from a public IPv4 block they own, such as a carrier's own address space or a legacy `/8`, so their gateway has no private address. List those blocks in the `gatewayInternalNetworks` managed…claude-apps-gateway see the edit
Confirmed since
Anthropic's documentation has since written up /login, on Use Claude Code in the cloud.
* ``Cloud sessions need a claude.ai sign-in. Run `claude auth login` (or /login in a local session), then try again.``claude-code-on-the-web 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 /login, on Use Claude Code in the cloud.
Anthropic's release notes agree
Fixed macOS /login reporting success when the keychain refused the new login and kept an old one it could not remove