MCP server · Developer tools
Just MCP server
Lets your AI see and run the ready-made commands in your project's Justfile, safely.
This is a helper that connects your AI assistant to Just, a tool many teams use to store their everyday project commands in one file called a Justfile. Once connected, your AI can look up which commands exist and run them for you, instead of guessing at the command line. It is handy if you work in a project that already has a Justfile and you want your AI to use it properly.
What is an MCP server? The 30-second version
On its own, your AI can only chat. An MCP server is a small helper program that gives your AI a new skill or a connection to another tool. This one connects your AI to Just, the command runner that reads your project's Justfile. So when you ask for something, the AI can check the Justfile and run the right command for you.
What this MCP server does
You ask your AI to do something in your project, like build or test it. The AI uses this helper to look at your Justfile and see which commands are available. The helper runs the command you picked, with any extra options you gave it. Then it sends the result back to your AI, which shows it to you in the chat. It can also check the Justfile for mistakes before anything runs.
Click to zoomWhat you can do with it
- List all the commands saved in your Justfile
- Run a command from the Justfile with the options you choose
- Show details about a single command, like what it does and what options it takes
- Check your Justfile for spelling or structure mistakes
- Use values from a .env file when running commands
Try asking your AI
- “What commands are available in this project?”
- “Run the build command with the release option”
- “Tell me what the test command does and what options it takes”
- “Check my Justfile for any errors”
What it gives back to you
You get back plain answers in the chat. When you ask for the list of commands, you see their names and short descriptions. When you run one, you see whatever that command printed, like build output or test results. If you ask for details about a command, you get its options and any notes written for it.
Before you start
What you need
- A project with a Justfile in it
- The Just command runner installed on your computer
- One of: Node.js, Python, Rust, Docker, or pkgx, depending on how you install this helper
- The Claude desktop app or another AI app that supports MCP servers
Good to know
It runs real commands on your computer, so only connect it to projects you trust and check what a command does before letting it run.
Install it with your AI
Add Just MCP server to your AI, no technical skills needed
You don't install anything by hand. You copy one prompt, paste it into an AI that can work on your computer, and it checks, installs and connects the server for you, asking you when it needs something.
Sign in to get the install prompt
Members get a ready-made prompt that lets the Claude desktop app check Just MCP server, install it and connect it for them, step by step. You don't need any technical skills: you copy, paste and answer a few questions. Your connected AI can also find and install any of the 4,066 MCP servers here for you.
Who it's for
Developers and technical teammates who already keep their project commands in a Justfile and want their AI to use them safely.
