MCP server

Baton ships a Model Context Protocol server (@baton/mcp) that exposes the core operations as MCP tools over stdio, so any MCP-capable harness can capture, validate, and resume handoffs without shelling out to the CLI.

Running it

baton-mcp

or directly from a checkout:

node packages/mcp/dist/server.js

The server is stateless per connection and operates on the project at the current working directory (resolved the same way the CLI resolves it).

Tools

Tool	Purpose
handoff_init	Initialize .baton/ for a project
handoff_capture	Create a draft handoff from structured fields
handoff_validate	Run the policy engine, return per-check results
handoff_ready	Promote a validated draft to ready
handoff_resume	Render the resume brief
handoff_list	List handoffs
handoff_detect	Feed adapter events / signals, get a suggestion
handoff_status	Project + session status snapshot
handoff_metrics	Event log summary

Tool results follow the same policy semantics as the CLI: a failed validation is a structured policy-error result (never a thrown exception), so agents can branch on the payload.

Parity

The MCP layer is a thin translation layer over @baton/core — the same functions the CLI calls. Contract tests in packages/mcp/tests/ assert that tool results match CLI behavior for the same inputs.