Files
tether/android
Patrick Ecord 3581c1e86c android: Compose client scaffold on tethercore (Kotlin/UniFFI)
Add an Android app that drives the same tethercore engine (SSE + RTC) as the
iOS/macOS apps via generated Kotlin/UniFFI bindings — proving the shared core
reaches a fourth language with no protocol reimplementation. Engine surface is
identical to Swift: Engine(server,room,from,source) / start / send / stop.

Includes the Gradle/Compose project, a TetherStore that bridges the engine to
ClipboardManager (auto-send via OnPrimaryClipChangedListener — Android allows
foreground clipboard observation, unlike iOS), per-install RoomIdentity, and
core/build-android.sh (cargo-ndk → jniLibs + Kotlin bindgen).

Not built here: this machine has no Android SDK/NDK, so the native .so and
Kotlin binding are generated (git-ignored), not committed. README documents the
NDK install + build steps. The binding itself was confirmed to generate.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-20 23:42:36 -05:00
..

tether — Android client

Compose UI over the shared tethercore Rust engine (SSE + RTC) via UniFFI Kotlin bindings. Same engine as the iOS/macOS apps and the desktop agent; only the UI and the binding language differ.

Build (requires the Android NDK)

This machine had no Android toolchain when the app was scaffolded, so the native .so and Kotlin bindings are not committed — they're generated:

  1. Install the toolchain:
    • Android Studio (SDK + NDK), or sdkmanager "ndk;26.x"
    • cargo install cargo-ndk
    • rustup target add aarch64-linux-android x86_64-linux-android
    • export ANDROID_NDK_HOME=/path/to/ndk
  2. Generate native libs + bindings:
    ../core/build-android.sh
    
    This places libtethercore.so under app/src/main/jniLibs/<abi>/ and the Kotlin binding under app/src/main/java/uniffi/tethercore/.
  3. Build/run the app: open android/ in Android Studio (it generates the Gradle wrapper on first sync), then Run. From the CLI, generate the wrapper once with gradle wrapper, then ./gradlew :app:assembleDebug.

Notes

  • Default server is http://10.0.2.2:8765 — the emulator's alias for the host machine's localhost. On a physical device use the relay's LAN address.
  • Android (unlike iOS) lets a foreground app observe clipboard changes, so the app auto-sends via OnPrimaryClipChangedListener. A foreground Service would extend that to the background (future work).
  • The room id is a per-install UUID (RoomIdentity); account-derived shared rooms are future work, matching the iOS plan.