Application Purpose
MIDI-HA Bridge is a lightweight macOS menu bar application that listens for incoming MIDI signals and forwards them as service calls to a local Home Assistant instance — allowing MIDI-capable devices or software to trigger smart home scenes, scripts, and automations automatically.
The app runs silently in the macOS menu bar and is used by individuals who operate Home Assistant for building or venue automation and want to control it via MIDI.
Why the App Uses Google Sign-In
MIDI-HA Bridge includes an optional email alert feature. When the MIDI connection or Home Assistant becomes unreachable, the app can send an automatic notification email so operators are alerted immediately — and again when service recovers.
Users who choose to receive alerts via their Gmail account can sign in with Google instead of entering SMTP credentials manually. Google Sign-In is the only path that uses OAuth. It is entirely optional; users may instead configure a custom SMTP server, or disable email alerts entirely.
OAuth Scopes Requested Read-only for identity · Send-only for email
https://www.googleapis.com/auth/gmail.send
Used solely to send alert emails from the user's own Gmail address to a destination address the user specifies. The app never reads, lists, or modifies any messages in the user's mailbox.
openid · https://www.googleapis.com/auth/userinfo.email
Used only to display the authenticated Gmail address in the Settings window so the user can confirm which account is connected. No profile data is stored or transmitted beyond the local machine.
Data Handling
- The OAuth access token and refresh token are stored locally on the user's Mac in the app's Application Support folder. They are never uploaded to any server.
- No usage data, telemetry, or personal information is collected by the developer.
- Emails are sent directly from the user's Gmail account via the Gmail API — the developer has no access to email content.
- The app communicates only with Google's OAuth endpoints, the Gmail API, and the user's local Home Assistant instance.
Who Uses This App
Individual users (home automation enthusiasts, AV technicians, venue operators) running the app on a single Mac. The app is used in home or small-venue settings where Home Assistant manages smart devices and MIDI control is desired.
Developer Contact
Developer: Hyunwoo Jo
Website: www.sound4u.net
Email: midi-ha@sound4u.net