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Android

GeoLibre runs as a native Android app built from the same React codebase via Tauri v2 mobile — no separate app. The webview UI is bundled in the APK, so the app shell works offline; map tiles and the heavier engines are fetched on demand (same as the desktop build).

What works on Android vs desktop

The Android build ships the full map workspace, Add Data, the Vector tools (Turf.js / in-browser GeoPandas via Pyodide), the SQL Workspace (DuckDB-WASM and the in-browser PGlite/PostGIS engine), the Python Console (Pyodide), geocoding, statistics, the AI assistant, story maps, and plugins.

Tools that depend on a local desktop process are hidden on mobile, because Android has no Python sidecar or local helper binaries:

  • Processing → Whitebox, Raster, Conversion, AI Segmentation (all need the Python sidecar)
  • Add Data → PostgreSQL (served by the local Martin tile server)

These are gated by a user-agent isMobile() check so they never appear and then fail. Everything else runs client-side.

Toolchain setup (one time)

You need the Android SDK + NDK, a JDK (17 or 21 — newer JDKs can break the Android Gradle Plugin), and the Rust Android targets. The cleanest, sudo-free layout keeps everything under a user-writable SDK at ~/Android/Sdk.

# 1. JDK 17/21 (or reuse Android Studio's bundled JBR at /opt/android-studio/jbr)
export JAVA_HOME=/path/to/jdk-21

# 2. Android SDK components (sdkmanager ships with Android Studio cmdline-tools)
export ANDROID_HOME="$HOME/Android/Sdk"
yes | sdkmanager --sdk_root="$ANDROID_HOME" --licenses
sdkmanager --sdk_root="$ANDROID_HOME" \
  "platform-tools" "platforms;android-36" \
  "build-tools;36.0.0" "ndk;27.3.13750724"
export NDK_HOME="$ANDROID_HOME/ndk/27.3.13750724"   # Tauri needs NDK_HOME

# 3. Rust + the four Android targets (install rustup if you don't have it)
rustup target add aarch64-linux-android armv7-linux-androideabi \
                  i686-linux-android x86_64-linux-android

NDK r27 (LTS) is the supported line for Tauri v2. Add the four exports to your shell profile so every session has them.

API 36 (Android 16), not 34: the Tauri v2.11 Android template generates compileSdk = 36 / targetSdk = 36, so Gradle needs the matching platform installed. It is also Google Play's floor — from 2026-08-31 new apps and updates must target API 36 to be accepted.

16 KB page sizes

Google Play rejects apps targeting Android 15+ whose native libraries are not aligned for 16 KB memory pages, and such libraries fail to load on 16 KB devices. NDK r28+ does this by default; r27 does not, so the flags are passed explicitly. Export this before an Android build (CI sets it at workflow level in .github/workflows/android.yml):

export RUSTFLAGS="-C link-arg=-Wl,-z,max-page-size=16384 -C link-arg=-Wl,-z,common-page-size=16384"

It has to be the RUSTFLAGS environment variable. Putting the same flags in target.<triple>.rustflags in a .cargo/config.toml does not work: the Tauri CLI sets RUSTFLAGS itself when it invokes cargo for Android, and an env RUSTFLAGS overrides the config file outright. The config-file form is silently ignored — it parses, it builds, and it ships 4 KB-aligned libraries that Play rejects. Tauri appends to an inherited value, so exporting it works.

Check the result on a built APK — the bytes Play actually receives:

unzip -o -q app-arm64-release-unsigned.apk 'lib/*/*.so' -d /tmp/apkcheck
"$NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-objdump" -p \
  /tmp/apkcheck/lib/*/*.so | awk '$1 == "LOAD" { print $NF }' | sort -u
# every value must be 2**14 or greater; 2**12 means the flags did not apply

Use llvm-objdump -p rather than readelf -l: readelf wraps each LOAD across two lines, so it is easy to parse the wrong column and read an address as an alignment. CI runs this same check over every packaged .so and fails on a regression.

Build

cd apps/geolibre-desktop
npx tauri android init                          # generate src-tauri/gen/android (once)
npx tauri android build --apk --split-per-abi    # release APKs, one per ABI (~40 MB each)
npx tauri android build --aab                    # universal AAB for Google Play
  • gen/android is generated (git-ignored) and regenerated on demand.
  • Build release, not --debug: the stripped, size-optimized Cargo profile makes each APK ~40 MB; a debug build is ~200 MB (unstripped .so with debuginfo).
  • --split-per-abi emits one APK per architecture instead of a single ~150 MB universal APK. Install the arm64 one on real phones.

  • Output: src-tauri/gen/android/app/build/outputs/apk/<abi>/release/app-<abi>-release-unsigned.apk, where <abi> is Tauri's short name — arm64, arm, x86, x86_64 — not the Android ABI directory name (arm64-v8a, armeabi-v7a) that appears inside the APK under lib/.

  • Sideload/GitHub-release path: the per-ABI APKs.

  • Google Play path: the universal AAB (Play generates per-device splits from it). Don't --split-per-abi the AAB — Play wants the one bundle.

The app is named GeoLibre on Android (the desktop build is "GeoLibre Desktop") and uses the package id org.geolibre.app, both set via src-tauri/tauri.android.conf.json, which also drops the Python backend from the Android bundle.

The Android id is overridden there rather than in tauri.conf.json on purpose: identifier is shared by every platform and also determines the macOS bundle ID, the Linux AppStream id, and the webview data directory. Changing it globally would orphan existing desktop users' settings and break the Linux/COPR/Homebrew packaging, all of which still key off org.geolibre.desktop.

Signing

Release APKs are unsigned. To install one, sign it (a debug key is fine for testing; use a real key for distribution):

BT="$ANDROID_HOME/build-tools/36.0.0"
KS="$HOME/.android/debug.keystore"   # auto-created by Android tooling; or make your own
# -P 16, not -p: -p only guarantees 4 KB, and Play requires the .so to sit on a
# 16 KB boundary inside the zip. Same flag CI uses.
"$BT/zipalign" -P 16 -f 4 app-arm64-release-unsigned.apk aligned.apk
"$BT/apksigner" sign --ks "$KS" --ks-pass pass:android \
  --ks-key-alias androiddebugkey --key-pass pass:android \
  --out geolibre-arm64.apk aligned.apk
"$BT/apksigner" verify geolibre-arm64.apk

The example signs the arm64 APK. Substitute the ABI you need throughout — app-x86_64-release-unsigned.apk → geolibre-x86_64.apk, and likewise for armeabi-v7a / x86. The emulator section below installs geolibre-x86_64.apk, which is this same walkthrough with arm64 swapped for x86_64.

For a real upload/release key:

keytool -genkeypair -v -keystore upload.jks -alias upload -keyalg RSA \
  -keysize 2048 -validity 10000

Continuous integration

.github/workflows/android.yml builds signed, per-ABI release APKs on each published GitHub release (and on demand via the "Run workflow" button) and uploads them as the geolibre-android-release-apks artifact. It signs with your release keystore when these repository secrets are set, and otherwise falls back to a throwaway debug key so the artifact is still installable for testing:

  • ANDROID_KEYSTORE_BASE64 — base64 -w0 upload.jks
  • ANDROID_KEYSTORE_PASSWORD
  • ANDROID_KEY_ALIAS
  • ANDROID_KEY_PASSWORD

It also builds a universal AAB and uploads it as the separate geolibre-android-play-aab artifact — but only on runs that have the real release keystore, since Play rejects a debug-signed bundle. Without the keystore the AAB build is skipped entirely rather than built and discarded. The AAB is not attached to the GitHub Release (an .aab is not user-installable).

Install / test

On a phone

  1. Enable Developer options (tap Build number 7×) and USB debugging.
  2. Sideload the signed APK: 
    adb install -r geolibre-arm64.apk
    Or copy the APK to the phone and tap it (allow "install unknown apps").

For live development with hot reload, connect the device and run npm run tauri android dev.

On an emulator

sdkmanager --sdk_root="$ANDROID_HOME" \
  "emulator" "system-images;android-36;google_apis_playstore;x86_64"
avdmanager create avd -n geolibre \
  -k "system-images;android-36;google_apis_playstore;x86_64" -d pixel_7
emulator -avd geolibre
# x86_64 APK to match the x86_64 system image — the emulator can translate the
# arm64 build, but far slower, and it would not exercise the x86_64 libraries.
adb install -r geolibre-x86_64.apk

If you ever rebuild with a different signing key, uninstall the old copy first (adb uninstall org.geolibre.app) — Android rejects updates whose signature changed. This also applies when moving between a sideloaded APK and the Play build: Play App Signing re-signs with Google's key, so the two are not upgrade-compatible.

Publishing to Google Play

The build side is covered by the CI workflow above; the rest is Play Console onboarding.

  1. Developer account ($25, one-time). Register as an organization rather than a personal account if you can: personal accounts created after 2023-11-13 must run a closed test with 12 opted-in testers for 14 consecutive days before they can apply for production access. Organization accounts are exempt.
  2. Play App Signing. Upload upload.jks as the upload key; Google holds the actual app signing key and re-signs each bundle. The repository's ANDROID_KEYSTORE_* secrets are that upload key — keep the keystore backed up, since losing it requires a Play support reset.
  3. Upload the AAB from the geolibre-android-play-aab CI artifact. The versionCode is derived from the version in tauri.conf.json and must increase on every upload.
  4. Store listing assets: 512×512 icon, a 1024×500 feature graphic, and at least two phone screenshots. Add 7-inch and 10-inch tablet screenshots too — Play down-ranks apps without them, and a GIS workspace is genuinely tablet-appropriate.
  5. Privacy policy URL — point at the published privacy policy.
  6. Data safety form. Declare each network destination honestly: geocoding, the AI assistant, basemap/tile fetches, and Google OAuth for Earth Engine. Note which are transmitted versus collected — GeoLibre does not operate a backend that retains user data, but the form asks per-purpose.
  7. Content rating questionnaire and target audience.

Before the first public release, re-read Known limitations below: several Add Data paths are inert on Android. A reviewer tapping one and getting nothing is a one-star review, so consider gating them on mobile the way the sidecar tools already are via isMobile().

Known limitations / follow-ups

  • Local-file sources (MBTiles, local rasters, project files) assume real filesystem paths; Android scoped storage returns content URIs, so those flows need adapting before they work natively.
  • The Download Offline Area tool relies on a service worker, which the Tauri builds (desktop and Android) don't use — it's a PWA feature. Native offline basemap caching (bundled/downloaded MBTiles/PMTiles) is a future enhancement.
  • Earth Engine OAuth uses a desktop loopback/multi-window flow; a mobile deep-link redirect is future work.