Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.247 Home All releases olderv2.1.246 v2.1.248newer
Claude Code v2.1.247

Remote tool hosts can announce themselves over the session channel

Not switched on
Useful2 Signal4
Remote Tools Notable not in their notes

Tools on another machine gain a third route over the session channel, gated off by default.

Session-channel remote tool hosts are fully wired but behind tengu_violin_wood, which is off absent server config.

Feature flag
tengu_violin_wood Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.247: on

Read once, for one account on one subscription tier, against v2.1.247. It isn't a statement about your account. What a flag value here can and cannot tell you

tengu_violin_woodCLAUDE_CODE_REMOTE_TOOLS_SESSION_CHANNEL
What

Tools hosted on another machine could previously only be reached over the device bridge or a local loopback, and a third route is added where the host announces itself over the session's own channel. Session-channel hosts are listed ahead of the other two and are dropped rather than kept as offline entries, but are otherwise handled identically to bridge hosts throughout the remote-tools code. The whole route is gated behind the account flag tengu_violin_wood, which is off unless an account's server-side config turns it on, and can be switched off locally with an environment variable.

Details
  • Setting CLAUDE_CODE_REMOTE_TOOLS_SESSION_CHANNEL=false when launching Claude Code disables the session channel, leaving the device bridge and local loopback routes in place.
  • A registry tracks announcements per host instance, including the case where one instance takes over from an earlier one for the same machine.
  • A tool call can wait a bounded time for a host to re-announce itself; once that wait gives up, the failure is remembered for the rest of that worker process's life instead of being retried on every call.
  • Retry handling gains the failure outcomes stalled, host_gone and host_withdrawn, along with explanations for calls that never left the client.
  • A call that cannot reach its host reports that it may be asleep, offline, not running, serving may be switched off on it, or its announcement could not be verified by this session.
  • Hosts expose a way to wait for an announcement and to report whether the device bridge was reached, and the announce control message subtype is recognised on this path.
Evidence

it may be asleep, offline, not running, serving may be switched off on it, or its announcement could not be verified by this session, CLAUDE_CODE_REMOTE_TOOLS_SESSION_CHANNEL

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.247 →