FriendNet for Android

An Android client for FriendNet, a peer-to-peer file sharing network developed by termermc. This app embeds the FriendNet Go client and wraps it in a native UI.

Features

• Servers — add, edit, connect to and disconnect from FriendNet servers
• Browse — browse a peer's shared folders and files, search across peers
• Downloads — queue, pause, resume, cancel and remove downloads; tap Open on a completed download to view it in an external app
• Settings — transfer directory info, check for app updates
• Logs — read the app's logcat output in-app (including the Go backend's logs) and save it to a file for easy debugging

How it works

The app cross-compiles the FriendNet Go client for Android and ships it as a native library. At runtime a foreground service (GoBackendService) spawns the client binary in headless mode:

• the backend listens on a Unix domain socket
• the app talks to it over gRPC with cleartext HTTP/2
• the RPC bearer token is read from the backend's startup logs

The Go submodule is kept pristine — no local patches are applied to FriendNet/.

Download locations

• Completed downloads go to the public Downloads/ folder.
• In-progress files are written to Downloads/.friendnet-incomplete/ (inside the same directory tree as the completed files, so the completion rename never crosses filesystems).
• Opening a completed file requires "All files access" (MANAGE_EXTERNAL_STORAGE); the app prompts for it on first launch.

Building

Requirements:

• Android SDK + NDK
• JDK 17+ (for example JAVA_HOME=/home/afim/.androidstudio/jbr)
• Go 1.26+ (a matching toolchain is auto-downloaded via GOTOOLCHAIN on first build)
• Internet access on the first build (to fetch Go modules and the toolchain)

Build the debug APK:

./gradlew :app:assembleDebug

assembleDebug runs the buildGoBackend task, which invokes build_backend.sh to cross-compile the Go backend for all three ABIs (arm64-v8a, x86_64, armeabi-v7a) into app/src/main/jniLibs/. The APK lands at app/build/outputs/apk/debug/app-debug.apk.

To skip rebuilding the Go backend during UI-only iterations:

./gradlew :app:assembleDebug -x buildGoBackend

To update the Go backend to the latest upstream:

git -C FriendNet fetch origin master
git -C FriendNet checkout origin/master
git add FriendNet && git commit -m "Update FriendNet to <commit>"

Debugging

The Logs tab shows the app's logcat output, which includes everything the Go backend prints to stdout/stderr. Use the Save button to export the logs to a file. However if you're comfortable with ADB, it is recommended to attach your device via USB debugging and access the application logs that way since those logs are more readable.