wtf is mainline?

Mainline is a small macOS app that lives in your menu bar and keeps track of GitHub pull requests for you, so you never have to keep a browser tab open just to check if someone reviewed your code. It watches the pull requests you opened and the ones where someone has asked for your review, and it notifies you the moment something changes, such as a PR turning green, a new review landing, or a CI check breaking. Instead of a plain list, Mainline groups pull requests by what actually needs your attention. There is an Inbox that separates PRs you need to review from PRs you opened yourself, and it can automatically mute noisy items like bot generated PRs or ones matching filters you set, so those slide into a quiet, collapsed group instead of cluttering your view. The app is built to be used almost entirely from the keyboard. You can move between PRs, open them, approve them, merge them, snooze them, or peek at their changed files, all without touching the mouse, and every key can be rebound to your liking. There is also a global keyboard shortcut to pop the app open from anywhere on your Mac. To use it, Mainline needs a GitHub token so it can read your pull requests. The easiest path is importing the token you already have from the GitHub command line tool, but you can also create a personal access token by hand. That token is stored securely in the macOS Keychain rather than in a plain settings file. Actions like approving or merging a PR directly from the app are optional and turned off until you enable them, each requiring a confirmation step. Mainline is written in SwiftUI and distributed through Homebrew. It requires macOS 13 or later and works only on Mac. Anyone who wants to build it from source needs Xcode 15 or newer. The project is released under the MIT license, so it is free to use, modify, and redistribute.