Ion

A simple editor for coding with AI agents

Your agent writes the code. Ion is where you watch it, review it and steer it.

Download · Features · Shortcuts · Roadmap

Why Ion

If you code with Claude Code, Codex, Gemini CLI or another terminal agent, most of your day is spent asking for changes and checking them. Ion is built for that.

It doesn't come with its own AI. Bring the agent you already use, run it in Ion's terminal, and Ion helps you keep track of what it's doing. It's free, open source, and there's no account to create.

What you can do

See what your agent changed

Open files update as the agent edits them. The file tree and the margin show what changed, and Source Control lists every modified file. Read the diffs inline or side by side, and undo any part you don't like.

Keep an eye on every agent

The Agents view shows each agent you're running, whether it's working or waiting for you, and the files it changed. Turn on Follow to watch the file it's editing as it goes. If an agent finishes or needs input while you're somewhere else, Ion lets you know.

Send errors back to the agent

When a build or test fails in the terminal, Ion picks up the errors, marks them in your code and lists them in Problems. Click Send to Agent and the agent gets the whole list to fix.

Run your project in one click

The ▶ button finds your project's scripts and targets (npm, pnpm, yarn, bun, Cargo, Go and Make) and runs each in its own terminal. Click a localhost:3000 link in the output to open it in your browser.

Find things quickly

Press Ctrl+P to jump to any file. Files you've had open, and files your agent just changed, show up first. Paste a location like src/app.ts:42 from the agent's output and you land on that line. Click file paths in the terminal to open them too.

Read plans and docs

A live Markdown preview sits beside the file, which is handy for an agent's PLAN.md. There's also an image viewer and word wrap.

Work on a server

Open a folder on a Linux machine or a Mac over SSH. Files, search, Git and terminals all run there, so your agent can too. Ion uses your usual SSH setup. More about remote projects.

And the everyday editing basics

• Multiple cursors, code folding and syntax highlighting
• Find and replace, and search across the project
• Split editors and terminals, and drag tabs anywhere
• Git: stage, commit, switch branches, blame, history, push and pull
• Dark and light themes, and Ion reopens where you left off
• Searchable settings, and shortcuts you can change to suit you

Works with your agent

Claude Code connects to Ion on its own when you start it in an Ion terminal (or run /ide from anywhere). It can then open files and diffs in Ion, see what you've selected, read your Problems list, and suggest edits you accept or reject.

Codex reads your open file, selection and tabs from Ion with each prompt once you run /ide in it.

Gemini CLI and any other terminal agent work as they do anywhere else. Select some code and press Ctrl+Alt+K to send it to the agent, drag files onto the terminal, or paste in an image.

Install

Download the latest release for Windows 11 or a Mac with Apple Silicon.

• Windows: unzip it and run ion.exe. There's no installer.
• Mac: unzip it and drag Ion.app to Applications.

Ion is still early, and the downloads aren't signed yet, so your computer may warn you the first time:

• Windows: choose More info → Run anyway.
• Mac: open Ion once, then go to System Settings → Privacy & Security and choose Open Anyway.

Build it yourself

You'll need Rust. On Windows, also install Visual Studio Build Tools with Desktop development with C++. On a Mac, run xcode-select --install. Then:

git clone https://github.com/neerajsunil/ion.git
cd ion
cargo dev

The first build takes a few minutes.

Shortcuts

On a Mac, use Cmd where you see Ctrl (except Ctrl+`, which stays the same).

Shortcut	What it does
Ctrl+P	Go to a file
Ctrl+Shift+P	Search all commands
Ctrl+`	Show or hide the terminal
Ctrl+Shift+A	Agents
Ctrl+Shift+G	Source Control
Ctrl+Shift+M	Problems
Ctrl+Alt+K	Send selection to your agent
Ctrl+Shift+V	Markdown preview

See all shortcuts.

What's next

Next up: checkpoints, so you can save a snapshot before a task and roll back afterwards, and staging single changes in Git. The roadmap has the rest, and the changelog has what's new.

Contributing

Ideas, bug reports and pull requests are all welcome. Please read CONTRIBUTING.md first.

License

Ion is available under the Apache 2.0 or MIT license, whichever you prefer. Anything you contribute is shared under the same terms.