Most AI app builders run in a browser tab. Your project lives on their servers and their AI edits it there; to work on it anywhere else, you export it or connect it to your own code repository. It is an easy way to start, and for many people it is the right one.
K2Coder works the other way round. It is a Mac app, your project is a folder on your disk, and the AI works on that folder where it sits. This month we reviewed that choice properly, against the alternative of moving every build into the cloud, and kept it. This post explains why.
What stays on your Mac?
Your project. It is an ordinary folder, in git, that you can open in any editor, copy, zip or delete. K2Coder never uploads your project to us. If you pay with Quantum Cloud credit, the parts of it the AI reads pass through our service on their way to the model; they are not stored there. When you deploy a site, it goes from your Mac to the host you chose, with your own account there. Today you deploy with your host's own tools. The next update adds a Deploy step in K2Coder for Vercel, Netlify and Cloudflare Pages that uses your own token and sends the files from your Mac to that host.
Your AI keys. If you save your own Gemini, OpenAI, DeepSeek or Kimi key in K2Coder's Settings window, it lives in your Mac's Keychain and goes from your Mac to that provider. A key added on the Providers card of K2Coder's Models page is saved in a plain text file in your home folder for now; moving every key you add in the app into the Keychain is planned for the next update. Your keys are never stored on our servers.
Your history. Chats, checkpoints and the project's notes about its own decisions are saved on your Mac, next to the project or in K2Coder's own folder.
What uses our cloud, and why?
One thing uses our cloud for your work: Quantum Cloud credit, for people who would rather not get their own AI keys. When you pay with credit, requests go through our service so that we can check your balance, set aside the cost and charge each request from the token counts the provider reports (an estimate if a request is cut off), never more than the amount set aside. That service records what it needs to run your account and bill you: your email address, which model, how many tokens, how long it took, what it cost, and an ID for the project and the build (never the folder's name), plus, when you sign in, a label with your Mac's name. These records are also written to our hosting provider's logs. The service does not store your prompts or the model's answers.
Apart from that, K2Coder only checks our server for updates (when it opens, and every 12 hours while it stays open), downloads an update from us when you choose to install one, and sends a crash report there if you agree to it.
Why not run every build in the cloud?
We costed it seriously. Running each build in its own cloud machine has a real advantage: a build carries on when you close your laptop. Three things outweighed it.
Your whole project would have to be copied to our machines by default. Today your project stays on your Mac. The files and results the AI works with are sent to the AI provider you chose (through our service if you pay with Quantum Cloud credit), and with a model running on your Mac through Ollama, those requests stay on your Mac. We did not want to change that for everyone to give some people a convenience.
The cost lands on you. Machines that sit ready for builds cost money every hour whether anyone is building or not. A tool that runs on the computer you already own does not need to recover that.
A problem in a shared system reaches everyone in it. A mistake on your own Mac affects your own Mac. We would rather keep it that way.
What does this mean in practice?
- K2Coder works without our servers. With your own keys, or with a model running on your Mac through Ollama (installed separately), it does not need our servers. By default it only checks us for app updates, and it keeps working if that check fails; otherwise it contacts us only if you sign in to Quantum Cloud or agree to send a crash report.
- You can leave whenever you like. Your keys are your own, and your projects need no exporting, because they were always ordinary folders on your Mac.
- Your Mac does the building. Builds run while K2Coder is open and stop when you close it, so there is no cloud machine idling on your bill, and nothing of yours running on a server you can't see.
Try it on a project of your own. K2Coder is free for Mac, and downloading it needs no account: quantumaccordbg.com/k2coder.