LocalhostWatcher

LocalhostWatcher is a macOS menu bar app that keeps your localhost apps visible, healthy, and easy to reopen.

It discovers active services on localhost, shows which ones actually respond, lets you open or stop them quickly, and can relaunch selected apps automatically after login.

Get the App

• Website
• Download DMG
• Release Notes

What It Does

• Lives quietly in the macOS menu bar as a lightweight utility.
• Detects active localhost apps and the process behind each port.
• Checks whether each detected service responds on http://localhost:<port>.
• Shows unhealthy services in both the menu bar state and the app popover.
• Lets you open, stop, or clean up services quickly.
• Saves selected apps so they can be relaunched automatically after login.
• Supports launch-at-login for the watcher itself.

Main Views

• Active: the localhost apps currently running on your Mac.
• Login: the saved apps you want back after login.

Menu Bar Behavior

• Left click opens the main popover.
• Right click opens the context menu.

Context menu actions:

• Refresh Now
• Kill All Unhealthy
• Show Active
• Show Login
• Launch Watcher at Login
• About Localhost Watcher
• Quit Localhost Watcher

Requirements

• macOS 14+
• Xcode command line tools / Swift 5.9+

Build From Source

Build:

swift build

Run tests:

swift test

Launch the app bundle in development:

./run-menubar.sh

Stop the running menu bar app:

./stop-menubar.sh

Packaging

The project is a Swift Package, but it is packaged into a standalone .app bundle by run-menubar.sh.

For release packaging, signing, notarization, and disk images, see docs/RELEASE.md.

Docs

• Landing Page
• Features
• Release Guide