Just MCP Server

Expose curated Justfile recipes via MCP for safe deterministic automation.

Local serverstdioPython

What is the Just MCP server?

Connect Just to Claude, Cursor or any other MCP client and it stops being a tab you switch to. Expose curated Justfile recipes via MCP for safe deterministic automation. The just mcp server is what makes that connection.

What the server does

A production-ready MCP server that provides seamless integration with Just command runner, enabling AI assistants to discover, execute, and introspect Justfile recipes through the standardized MCP protocol.

Installation

just-mcp on npm is all you need. Most clients run it directly, so configuration is a few lines and a restart.

Available tools

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

  • Installation — The Installation tool exposed by this server
  • Validation — The Validation tool exposed by this server

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.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

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. Just's toolset — Installation, Validation — is a fair guide to whether it matches your workflow. It is maintained by PromptExecution; 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.

Available tools

ToolWhat it does
InstallationThe Installation tool exposed by this server.
ValidationThe Validation tool exposed by this server.

How to install the Just MCP server

#### Using pip/uvx
```json
{
  "mcpServers": {
    "just-mcp": {
      "command": "uvx",
      "args": ["just-mcp", "--stdio"]
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Example prompts to try

  • Use Just to Installation.
  • Use Just to Validation.

Frequently asked questions

It connects Just to MCP-compatible AI assistants such as Claude and Cursor, exposing 2 tools (Installation, Validation) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Just directly.