Build WasmEdge for Android

The WasmEdge Runtime releases come with pre-built binaries for the Android OS. Why WasmEdge on Android?

• Native speed & sandbox safety for Android apps
• Support multiple dev languages — eg C, Rust, Go & JS
• Embed 3rd party functions in your android app
• Kubernetes managed android apps

However, the WasmEdge installer does not support Android. The user must download the release files to a computer, and then use the adb tool to transfer the files to an Android device or simulator. We will show you how to do that.

• WasmEdge CLI tools for Android
• Call WasmEdge functions from an NDK native app
• Call WasmEdge functions from an Android APK app

Build from source for Android platforms

Please follow this guide to build and test WasmEdge from source code with Android NDK.

note

In current state, we only support the runtime for the interpreter mode.

Prepare the Environment

We recommend developers to use our Docker images and follow the steps to prepare the building environment.

• Download and extract the Android NDK 23b.
• Check the cmake for CMake 3.21 or greater version.
• Download and install the ADB platform tools.
  • If you use the debian or ubuntu Linux distributions, you can install the ADB platform tools via apt.
• An Android device which is enabled developer options and USB debugging and with at least Android 6.0 or higher system version.

Build WasmEdge for Android platforms

Get the WasmEdge source code.

git clone https://github.com/WasmEdge/WasmEdge.git
cd WasmEdge

Add the Android NDK path into the environment variable.

export ANDROID_NDK_HOME=path/to/you/ndk/dir

Run the build script in WasmEdge source code. This script will automatically build the WasmEdge for Android, and the results are in the build folder.

./utils/android/standalone/build_for_android.sh

Test the WasmEdge CLI on Android platforms

Push the WasmEdge CLI and related test data onto Android platforms

1. Connect the device by using a USB cable or Wi-Fi. Then you can check the attached devices via the adb devices command.

   $ adb devices
   List of devices attached
   0a388e93      device

2. Use the adb push command to push the entire build/tools/wasmedge folder into the /data/local/tmp folder on your Android device.

   cp -r examples build/tools/wasmedge/examples
   cd build
   adb push ./tools/wasmedge /data/local/tmp

Run WasmEdge CLI on Android platforms

1. Please use the adb shell command to access into the Android device.
2. Follow the steps to test the WasmEdge CLI on the Android device.

$ cd /data/local/tmp/wasmedge/examples
$ ../wasmedge hello.wasm 1 2 3
hello
1
2
3

$ ../wasmedge --reactor add.wasm add 2 2
4

$ ../wasmedge --reactor fibonacci.wasm fib 8
34

$ ../wasmedge --reactor factorial.wasm fac 12
479001600

$ cd js
$ ./../wasmedge --dir .:. qjs.wasm hello.js 1 2 3
Hello 1 2 3

Notice

• For the Android 10 or greater versions, SELinux will disallow the untrusted applications' exec() system call to execute the binaries in home or /data/local/tmp folder.
• The Android SELinux policy will disallow the untrusted applications to access the /data/local/tmp folder.