Kinhin

Turn your Mac into an autoscaling CI runner pool

Mac

Open Source

GitHub

I'm Alex Rabin. I've been writing code for 10 years and I have a full-time programming job. Before this I built SupDesk, a support console for solo founders. More of my work is at alexrabin.com. I don't write code by hand anymore. I build with AI agents, primarily from Claude and Freebuff, and I only use models that don't train on my data. I decide what gets built and I review and test the result; the agents type the code. How this was built says what that means for testing. About three months ago at my day job I set up a self-hosted Gitea runner for our Flutter app. One Mac needed to build for iOS, Android and the web, so I installed every toolchain by hand — Xcode and CocoaPods, the Android SDK, Chrome, and FVM to pin the Flutter version. It worked. It also took far longer than it should have. Then my own projects needed the same thing. I run their CI on GitHub Actions and kept hitting the free monthly minutes limits. Mac minutes are the expensive ones, and I need them for anything Apple-related. Self-hosting fixes the cost, but it meant doing all of that setup again on a different forge, and I didn't want to do it ever again. A plain self-hosted runner also only fixes the cost. It runs one job at a time, and the usual fixes each have a catch: many runners on one OS share a filesystem and ports, long-lived VMs idle on your RAM and disk, and hand-rolled autoscaler scripts have to be rewritten per CI platform. kinhin is the tool I wanted both times: one engine that handles the scaling, the isolation and the toolchains, whichever forge the jobs come from. The longer write-up is on https://kinhin.dev/guide/why-kin...