A free AI coding assistant that works in your project folder

MatrixX Code is the coding assistant inside MatrixX. Open your project folder, describe what you want ("the tests fail, find the bug and fix it", "add a dark mode toggle", "explain how this project is organised") and it gets to work: it reads the code, plans the steps in a to-do list, edits the files and runs the tests or the build to check its work.

You stay in control. Every edit is shown as a diff (green for added lines, red for removed) and is only saved when you say yes, every command asks first, and each request's changes can be undone. Plan mode lets it research and propose a plan without changing anything, and your conversations are saved as sessions you can come back to.

MatrixX Code is in MatrixX 0.1.4 for Windows. The Mac app gets it in its next update.

Download MatrixX free Try it on the website

How to do it

  1. Install MatrixX and create a free account

    Windows 10 or 11. No AI keys needed (you can add your own).

  2. Open MatrixX Code and pick your project folder

    It only works inside the folder you choose.

  3. Say what you want

    Approve each change as it shows you the diff, or switch to "accept edits" with Shift+Tab when you trust it.

Things you can ask

Questions

Does it change my files without asking?

No. Every edit is shown as a diff and saved only when you say yes (unless you switch to accept-edits mode), and every command asks first.

Can I undo what it did?

Yes. Each request's changes are kept in a history, and one command puts the files back. You can also rewind the conversation to an earlier message.

Which languages does it work with?

Any code in text files: Python, JavaScript and TypeScript, HTML and CSS, and more. It runs Python tests with pytest and Node tests with npm test.

Is it free?

Yes, the free plan has 25 messages a day. Paid plans use stronger AI models, which help on bigger projects.

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