Building from source

Kav's app is Kotlin and Jetpack Compose, built with Gradle. Everything below runs without root and without installing system packages.

What you need

• Linux on x86-64 for the toolchain script below. On another system, install JDK 21 and the Android SDK (platform 36, build tools 35.0.0) yourself and point JAVA_HOME and ANDROID_HOME at them.
• Git, and Python 3 for the timetable.

Get the code

git clone https://github.com/ImNoammm/kav.git
cd kav

The toolchain

tools/android_toolchain.sh downloads JDK 21 and the Android SDK into ~/Android, and nothing anywhere else. rm -rf ~/Android undoes it.

tools/android_toolchain.sh

Build the APK

tools/android_build.sh runs Gradle with that toolchain; anything after it goes to Gradle.

tools/android_build.sh :app:assembleRelease

The APK is android/app/build/outputs/apk/release/app-release.apk. Install it on a phone with USB debugging on:

~/Android/Sdk/platform-tools/adb install -r android/app/build/outputs/apk/release/app-release.apk

To run the unit tests:

tools/android_build.sh :app:testReleaseUnitTest

Your build has your signature

A release build is signed with your own machine's debug key (~/.android/debug.keystore), not Kav's. Android won't install it over the official app, or the official app over it, without uninstalling first, and Kav's links won't open it straight from the browser, because those are verified for Kav's own key.

Kav's server answers official builds only

The app signs its requests to Kav's server with a key that isn't in the repository. A build of your own works with every other source: Bus Nearby, EGG, the public website provider, and a server of your own.

The timetable

The APK carries no timetable. A nightly GitHub Actions run compiles the Ministry of Transport's GTFS feed and Tel Aviv's weekend lines into the file Kav downloads (about 6 MB), signs its manifest, and publishes it to the timetable release. To compile one yourself:

tools/fetch.sh
KAV_FROM=today KAV_REGION=il KAV_BBOX=national KAV_MANIFEST=1 python3 tools/export_web_bundle.py

tools/fetch.sh downloads the ministry's feed into .cache/ (about 180 MB). The result lands in .cache/timetable/, or wherever KAV_OUT points.

How releases are made

Pushing a version tag (v3.3.1) starts the release workflow on GitHub. It builds the APK from that exact commit, signs it with Kav's key, checks the certificate is the one every release so far has used, records a build attestation, and attaches the APK to the tag's release. Anyone can check a download came from there:

gh attestation verify kav-3.3.1.apk --repo ImNoammm/kav

The server

Kav's server is Python (server/live.py), OpenTripPlanner and a predictor, all in Docker. Building its images from source and releasing them are in the self-hosting guide, under For developers.

Contributing

Bugs and ideas are welcome as issues, and fixes as pull requests. Kav is GPL-3.0, and so is anything merged into it.