# Gearslip Bring any app to your car screen. ## What Gearslip is Gearslip is an Android Auto client for the phone. It speaks the Android Auto protocol directly to a car head unit over USB, with no Google software in the path. Gearslip acts as a Car App Library host: an app that ships a car interface hands Gearslip a template, and Gearslip renders that template natively on the car screen. Nothing is mirrored from the phone. For apps without a car interface, Gearslip offers a separate screen-sharing mode. ## Features - **Phone calls.** Dial from a keypad, or search your contacts, then confirm before the call goes out. - **Navigation.** Gearslip hosts real Car App Library map apps on the car screen; Organic Maps and OsmAnd both work today. - **Music.** Browse, play, and queue tracks from a car-enabled media app, with a Now Playing view, an Up Next queue, and lyrics. - **The web.** A browser template with its own on-screen keyboard, for anything that doesn't ship a car interface of its own. - **Weather and the day ahead.** A dashboard screen shows the week's calendar next to the current and coming weather. - **Messages.** New messages appear as a small card on the car screen. Gearslip reads each one aloud, and you reply by voice or with a quick reply. Speech runs on the phone, so it needs no Google account. - **Notifications.** Only messages, missed calls, alarms, and reminders interrupt you. The rest wait on the dashboard. - **Car controls.** Steering wheel buttons, control knobs, and D-pads all work. - **Themes.** Choose flat buttons or skeuomorphic ones that look like real keys. ## Status - **The connection is wired only, for now.** Plug the phone into the head unit's USB port; Gearslip does not yet offer a wireless option. - **Setup walks you through it.** First launch asks for the Android Auto certificate, then one permission at a time, each with a plain reason and an Allow or Skip. A help screen inside the car answers anything setup didn't cover. - **Templated apps work.** Gearslip renders all 16 template types that the Car App Library defines, and it draws its own keyboard for search, sign-in, and text fields. It has been tested against several real navigation and media apps. - **Gearslip works with [LIVI](https://github.com/f-io/LIVI),** the open-source head unit used in homemade car dashboards. - **Some apps refuse Gearslip.** Spotify, Waze, and Google Messages use a version of Google's car library that accepts only Android Auto itself. Spotify still plays through Gearslip's own player. - **For now, Gearslip works with cars from before 2020.** Newer head units reject its certificate. - **Calls use the car's Bluetooth,** as they do in Android Auto. Pair the phone with the car to hear calls through its speakers. - **Audio reaches the car by capturing playback, not by mirroring the screen.** Android shows a screen-share consent dialog for this, even though Gearslip never reads the screen; it is the only way an ordinary app can capture another app's audio. The dialog appears once per drive. - **Gearslip needs no adb, root, or Shizuku.** Every feature relies on an ordinary Android permission or an on-device consent dialog. The setup guide offers two optional adb commands: one removes the audio dialog for good, and the other keeps notifications visible while audio plays. ## Building ``` ./gradlew :gearslip:assembleDebug ``` The APK lands at `build/Gearslip-debug.apk`. A release build needs a signing key. Copy `keystore.properties.example` to `keystore.properties`, fill in your own values, and run `./gradlew :gearslip:assembleRelease`. Git ignores both the properties file and the keystore. Without them, the debug build still works. ## Writing apps for Gearslip [docs/BUILDING_APPS.md](docs/BUILDING_APPS.md) specifies how to write apps that Gearslip can render: templated apps, media apps, and the Gearslip app protocol. ## Trademarks Android, Android Auto, Google Messages, and Waze are trademarks of Google LLC. Spotify is a trademark of Spotify AB. Gearslip is not affiliated with, endorsed by, or sponsored by any of these companies. All other names belong to their owners. ## License Gearslip is licensed under AGPL-3.0; see [LICENSE](LICENSE). The author offers a separate commercial license for private use outside the AGPL's terms; see [NOTICE.md](NOTICE.md).