MacOS tray icon disappears after a few hours of usage

[ummon-v]

After a few hours of use, the tray icon disappears. Running killall SystemUIServer refreshes the entire menu bar, but the MCP Proxy icon does not reappear.

The application itself is still running without issues:

ummon 80281   0.0  0.2 436905072 131424   ??  S     4:16PM   9:38.65 /Users/ummon/Library/Application Support/mcpproxy/bin/mcpproxy serve
ummon 80280   0.0  0.1 437152784  94176   ??  S     4:16PM   2:34.40 /Applications/mcpproxy.app/Contents/MacOS/mcpproxy

There are no errors in ~/Library/Logs/mcpproxy/tray.log.

Since the app is still running, relaunching it has no effect. The only workaround is to manually kill both processes and restart the application — at which point the tray icon reappears and the menu (used to access the web interface with authentication) becomes available again.

[Dumbris]

Thank you for the detailed report! The process still running while the icon vanishes is a really helpful clue.

I suspect this is a bug in the fyne.io/systray library we use for the Go-based tray app. The library uses CGO to interact with the macOS menu bar, and the NSStatusItem can become orphaned when macOS's SystemUIServer reclaims menu bar space — typically after prolonged usage, sleep/wake cycles, or memory pressure. Since the library doesn't re-register the icon after this happens, the process keeps running but the icon is gone.

The good news: I'm actively working on a completely new native macOS tray app written in Swift. It uses NSStatusItem directly (no CGO bridge), which is significantly more resilient to SystemUIServer restarts. The new version will also be more feature-rich — server detail views, tool inspection, import from Claude Desktop config, and more.

In the meantime, as a workaround you can restart just the tray process:

killall -9 mcpproxy; open /Applications/mcpproxy.app

The Swift tray is coming in the nearest days. I'll update this issue when it ships.

[ummon-v]

Thanks a lot for feedback.

I can confirm I experience this behavior mostly during a sleep/wake cycles.

Will be happy to test new implementation when ready.
Keep it up!