Our story

A second look at your code, without sending it to a model.

I'm Johnny Mobley. I started building systems for other people in 2000, when I was 16, and I've been doing it ever since. Along the way I automated most of my own work, and the tools I built for myself became these companies. Each one runs on rules I wrote down, not on paid AI calls, which is why it can cost so little.

Sometimes you just want someone to look at a function before you ship it: is there an obvious bug, a security hole, a slow loop, a missing test? I built Halside to give that second look from the browser or the terminal, with no account and no key.

It runs on review rules I wrote by hand, not an AI model, so it catches the patterns it knows and nothing else. Treat what it says as a starting point to check yourself; it never runs your code.

What works today

• Reviews a pasted snippet for bugs and security problems
• Takes an error message and the code around it and suggests a likely cause and a fix
• Drafts test cases for an untested function
• Points out slow spots in a snippet
• Every tool is a plain JSON endpoint you can call with curl, no key needed

What it doesn't do yet

CodeRabbit still does things Halside doesn't:

• Reviewing pull requests on GitHub or GitLab automatically.
• Reading your whole repository; Halside sees only the snippet you paste.
• Learning your team's preferences from feedback.
• IDE plugins.

What it costs

CodeRabbit's price is from their pricing page as of October 29, 2026. Prices change, so check theirs before you compare.

— Johnny