{"version":"2.1.247","anchor":"control-protocol-for-tools-hosted-on-an-attached-machine","canonical_anchor":"control-protocol-for-tools-hosted-on-an-attached-machine","heading":"Control protocol for tools hosted on an attached machine","tier":"soon","area":"Remote Tools","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.247\/e\/control-protocol-for-tools-hosted-on-an-attached-machine","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.247","markdown":"### Control protocol for tools hosted on an attached machine\n\nA cloud worker can call tools hosted on your attached machine, but the account flag is off.\n\n**What**\n\nThe 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.\n\n**Details**\n\n- Request subtypes are `remote_tools_announce`, `remote_tool_call`, `remote_plumbing_call` and `remote_tools_probe`, each with a success payload.\n- Announcements carry an instance id and a description of the host machine.\n- Error codes are `remote_tools_disabled`, `remote_tools_not_ready`, `stale_worker_epoch` and `invalid_announce`.\n- 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.\n\n**Evidence**\n\n`remote_tools_announce`\n\n- Flag `tengu_violin_wood`: Off in both readings (read for one account on one subscription tier against v2.1.247; this account: off, anonymous baseline: off, compiled default: off)\n- Area: Remote Tools\n- Names: `tengu_violin_wood`\n- Tier: Nothing to try yet\n- Useful: 2\/5\n- Signal: 4\/5\n- Present in the build but not switched on"}