An Android Auto alternative built for everyone.

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Most cars work. Starting around 2020, some cars added newer security standards that reject Gearslip's certificate, and Gearslip can't run in those cars. CARS.md lists the cars drivers have confirmed.

Gearslip is an Android Auto client for the phone. It speaks the Android Auto protocol directly to a car head unit, over USB or wirelessly, 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.

Your car apps in one place. A red X marks the ones that don't work yet.	Vela Maps navigating, with the player beside it.
ViVi Music in Gearslip's player.	A new message, read aloud at a tap, over the map.
The weather, your next event, and what you missed.	Browse the web while parked.
Ask for a place, a song, or an app.	Find coffee nearby without leaving the map.

• Phone calls. Dial from a keypad, or search your contacts, then confirm before the call goes out. When a call comes in, answer or decline it on the car screen.
• Navigation. Gearslip hosts real Car App Library map apps on the car screen. Organic Maps, OsmAnd, and Flitsmeister work today. Vela runs, with rough edges.
• Music. Browse, play, and queue tracks from a car-enabled media app, with a Now Playing view, an Up Next queue, and lyrics. Type a search, and apps that accept one play the best match.
• 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.
• Voice. Tap the mic, or press the talk button on the wheel, and say "navigate to the nearest gas station", "play Daft Punk", or "call Mom". Say "help" for the full list. Speech turns into text on the phone, and nothing you say leaves it.
• 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. Music pauses while Gearslip speaks or listens. 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.
• Your apps, your order. The launcher groups apps by kind: phone, maps, music, messaging, and the rest. Press and hold an app to move it.
• Car controls. Steering wheel buttons, control knobs, and D-pads all work.
• Themes. Choose flat buttons or skeuomorphic ones that look like real keys.

• Wired or wireless. Plug the phone into the car's USB port, or, in a car with wireless Android Auto, tap Connect wirelessly and pick the car. Pair the phone with the car over Bluetooth first.
• 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, 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.
• Calls use the car's Bluetooth, as they do in Android Auto. Pair the phone with the car to hear calls through its speakers.
• Music reaches the car over Bluetooth or USB. Setup asks which. Bluetooth is the default: Android never asks for permission, and your map app's voice reaches the car too. USB sounds a little clearer, with no delay, but Android shows a screen-share consent dialog once per drive. Gearslip never reads the screen; capturing playback is the only way an ordinary app can pass another app's audio along.
• Gearslip needs no adb, root, or Shizuku. Every feature relies on an ordinary Android permission or an on-device consent dialog. For USB audio, setup offers two optional adb commands: one removes the audio dialog for good, and the other keeps notifications visible while audio plays.
• Updates come from GitHub. Once a day, Gearslip checks this repository's latest release. When a new version is out, it downloads the APK, checks it against GitHub's SHA-256, and installs it through Android's own installer. Turn off automatic checks in Settings.

Check that your copy of Gearslip is genuine with AppVerifier: share this block to it, or compare it with the output of apksigner verify --print-certs.

app.seb3thehacker.gearslip
4C:C5:6E:BD:D1:3A:54:D2:60:EC:A9:B7:E2:B2:AE:6B:30:E2:F2:25:BF:DA:8F:50:8F:07:09:ED:F0:84:94:8B

Gearslip can send short notes that show which cars it works in. They stay off unless you turn them on, in setup or in Settings.

• When they go out. When you open Gearslip, at most once a day, and after each drive. Nothing runs in the background.
• What they carry. The Gearslip version and which boxes you ticked, plus whatever those boxes cover: the Android version and whether the phone runs GrapheneOS, the phone model, whether a car connected that day, and each car's head unit, model, year, screen size, and connection result, with whether that drive used the cable or wireless and whether music went over USB or Bluetooth. If you tick it, how each drive went: how far the connection got, how long it lasted, and how it ended. Settings shows the exact note. Untick a phone detail, and the server drops the copy it kept.
• What they leave out. Your name, accounts, location, contacts, messages, and anything you type or play.
• How phones are counted. A random number counts each phone once. The server keeps only a salted hash of it.
• Where they go. To Gearslip's server. Like any website, it sees your IP address when a note arrives, and it doesn't store it.

Turn the notes off, and they stop at once.

Gearslip is my beloved child. I decide what it does and how it looks, and Claude writes nearly all of the code. I test every change myself before it ships: in a real car, with both a GrapheneOS phone and a stock Android phone, and on LIVI, the open-source head unit software. I watch the phone's temperature too, so a new feature doesn't cook it. Then I beg my friends to try it in their cars, so it works in as many makes, models, and years as possible. If something breaks, that's on me, so please open an issue.

Bug reports from real cars help most, and pull requests are welcome. CONTRIBUTING.md explains what to put in a report, which branch to work on, and the one-time agreement you sign before your first pull request merges.

./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.

docs/BUILDING_APPS.md specifies how to write apps that Gearslip can render: templated apps, media apps, and the Gearslip app protocol.

Gearslip is an independent program, written to work with car head units. What it knows of the protocol comes from public open-source projects such as aasdk and open-android-auto, and it contains none of Google's Android Auto code.

Gearslip ships without a certificate. On first launch you choose where yours comes from: download the one the aasdk project publishes, or import a file of your own. The certificate stays on your phone. Gearslip never uploads, backs up, or logs it.

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.

Gearslip belongs to Twink Software LLC and is licensed under AGPL-3.0; see LICENSE. The LLC also sells a separate commercial license for private use outside the AGPL's terms; see NOTICE.md.