Source Intelligence
Follow Discord

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

Control protocol for tools hosted on an attached machine

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

A cloud worker can call tools hosted on your attached machine, but the account flag is off.

Four new machine-tool requests exist in the control protocol, gated on account flag tengu_violin_wood which compiles off.

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_wood
What

The control protocol between a cloud worker and an attached CLI gains four new requests: an announcement of the tools a machine offers, a call of one of them, a call of internal plumbing, and a liveness probe. An announcement carries up to 16 native tools and up to 256 passthrough MCP tools. This replaces an older tools-list announcement and is gated on an account flag, tengu_violin_wood, whose built-in fallback is off.

Details
  • Request subtypes are remote_tools_announce, remote_tool_call, remote_plumbing_call and remote_tools_probe, each with a success payload.
  • Announcements carry an instance id and a description of the host machine.
  • Error codes are remote_tools_disabled, remote_tools_not_ready, stale_worker_epoch and invalid_announce.
  • The schema states that workers only emit the related worker-epoch field when the account's remote-tools flag is on, and nothing in this build supplies a value for that flag, so it comes from server config.
Evidence

remote_tools_announce

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

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.247 →