Unison MCP Server

Connect Unison MCP to Claude, Cursor or any other MCP client and it stops being a tab you switch to. Unison言語のModel Context Protocol (MCP)サーバー実装です。AIアシスタントがUCM（Unison Codebase Manager）を操作できるようにします。. The unison mcp mcp server is what makes that connection.

Available tools

The toolset is worth reading before you wire it up, because it tells you what the integration is really for:

• mcp__unison__ucm_find — 定義の検索
• mcp__unison__ucm_add — 新しい定義の追加
• mcp__unison__ucm_run — Unison式の実行
• mcp__unison__ucm_view — 定義のソースコード表示
• mcp__unison__ucm_update — 既存定義の更新
• mcp__unison__ucm_ls — 名前空間の内容一覧
• mcp__unison__ucm_delete — 定義の削除
• mcp__unison__ucm_test — テストの実行（scratch.uがない場合は自動生成）
• mcp__unison__ucm_dependencies — 定義の依存関係表示
• mcp__unison__ucm_list_projects — プロジェクト一覧
• mcp__unison__ucm_switch_project — プロジェクトの切り替え
• mcp__unison__ucm_project_create — 新規プロジェクト作成

Installation

Setup follows the usual MCP pattern — install or clone the server, register it in your client's configuration file, restart the client.

Where it fits

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Unison MCP's toolset — mcp__unison__ucm_find, mcp__unison__ucm_add, mcp__unison__ucm_run and 11 more — is a fair guide to whether it matches your workflow. It is maintained by mizchi; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Worth knowing first

• It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
• With 14 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Unison MCP.
• Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.