Basics

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Magnum is an agentic development environment (ADE), a desktop app for running coding agents: Claude Code, Codex and Pi. It runs on macOS and Linux, with projects on this computer and on machines you reach over SSH. An agent works on a task in a session, and the sidebar shows every session and whether it needs you.

Installing Magnum

On a Mac with Apple silicon, run this in Terminal:

curl -fsSL https://magnumade.com/macos/install.sh | bash

It puts Magnum in Applications, replacing an older copy, and opens it. The .dmg is also on the latest release's page.

On Linux, on x86_64 or aarch64:

curl -fsSL https://magnumade.com/linux/install.sh | bash

It puts magnum in ~/.local/bin, with an entry in your applications menu.

Magnum updates itself: when a new version is out, a notification says so and Update shows at the bottom of the sidebar, with what's new and a Restart when it's ready.

The first launch

The first time it opens, Magnum asks whether to share anonymous usage (Privacy says exactly what that sends). Choose, then Get started; Settings → General changes it later.

Magnum uses the agents already installed on this computer, and their sign-ins. While something it needs is missing (no agent at all, no Git, or no name and email for Git), the start screen lists what it found:

⌘P → Set up this Mac… (Set up this computer… on Linux) shows the list again.

Opening a project

A project is a folder. On the start screen choose Open folder…, or press ⌘O to pick a recent project or open a folder. Opening a project reopens the sessions you left open there, or starts a new one, and lists the project in the sidebar until you remove it.

To work on another computer over SSH, choose Add instance… on the start screen or in ⌘O: see Machines.

Your first session

A new session shows Magnum's ibex and name in dots; the message box names the agent ("Ask Claude…"). Type what you want there and press ↩. What the agent does shows as it happens. When it asks to edit a file or run a command, the request sits on top of the message box: Allow (⌘↩) or Deny (⌘⌫).

If the agent isn't signed in, a card above the message box signs it in, in your browser. Agents and models has the details, and how to switch a project to Codex or Pi.

The command palette

⌘P searches Magnum's commands, your sessions (by title and by what was said in them), the agent's / commands, projects, the project's files and this Guide, all at once. When you don't know where something is, start there. Linux has no menu bar: the Help menu's commands are in ⌘P too.

⌘/ shows every keyboard shortcut, as does Keyboard shortcuts.

The tour and this Guide

The tour shows Magnum over your own window in about a minute, in nine steps: Sessions, The message box, Where it runs, Balanced, Magnum Router, The Board, Run and Ship, Tabs and tiles, That's it. Magnum offers it as the first tip on the first run; Help → Take the Tour and ⌘P → Take the tour start it again.

This Guide opens from Help → Magnum Guide (⌘?) or ⌘P, and it's on the website at magnumade.com/guide.

When Magnum starts, a tip may show at the bottom of the sidebar, at most one a day. ✕ closes it; right-click it for Show Me, Read in the Guide and Turn Off Tips. Settings → General → Tips turns them off or on.

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