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

Plumbing calls and passthrough MCP tools: described in the protocol, not yet served

Not switched on
Useful1 Signal4
Remote Tools

The attached-machine protocol describes plumbing calls and passthrough MCP tools that this build cannot serve.

The schema documents internal plumbing calls and machine-hosted MCP tools, stating outright that they are carried but not yet served.

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

What

The protocol for tools on an attached machine describes two things this build cannot do. One is a plumbing call, a tool call made by the session's own machinery rather than by Claude, described as being only directory sync's file-sync tool today. The other is carrying the machine's own MCP tools in an announcement, which the schema itself says are carried but not yet served.

Details
  • The plumbing request appears only in the schema, in a host-side validator that rejects it as agent-originated, and in two message classification lists. No code answers one.
  • The file-sync tool named in the description does not exist anywhere in this build.
  • The surrounding remote-tools feature is gated on the account flag tengu_violin_wood, compiled in as off, so none of this is reachable without a server value.
Evidence

carried now, not yet served over this channel.

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 →