Skip to main content
Version: 0.2

Kotlin SDK

In this section, you'll learn how to build a Kotlin SDK using Mopro's native bindings. The process includes the following steps:

  1. Generate the binding using the Mopro CLI
  2. Integrate the binding into a Kotlin Package
  3. How to install the Kotlin SDK via JitPack
  4. How to use the package

Generate the bindings using the Mopro CLI​

To get started with building Mopro bindings, refer to the Getting Started section. If you’d like to generate custom bindings for your own circuits or proving schemes, see the guide: Rust Setup for Android/iOS Bindings.

Then you will have a MoproAndroidBindings in the project directory.

Integrate the bindings into a Kotlin Package​

  1. Clone the SDK template repository:
git clone https://github.com/zkmopro/mopro-kotlin-package
  1. Replace the generated bindings:

Replace the bindings directory MoproAndroidBindings/uniffi and MoproAndroidBindings/jniLibs with your generated files in the following location:

  • android/app/src/main/java/uniffi
  • android/app/src/main/jniLibs

Alternatively, you can run the following commands to copy your generated bindings into the correct location:

cp -r PATH/TO/MoproAndroidBindings/uniffi android/app/src/main/java
cp -r PATH/TO/MoproAndroidBindings/jniLibs android/app/src/main

How to install the Kotlin SDK via JitPack​

To get this library from GitHub using JitPack:

Step 1. Add the JitPack repository to your settings.gradle.kts at the end of repositories:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
        mavenCentral()
        maven { url = uri("https://jitpack.io") }
    }
}

Step 2. Add the dependency to your build.gradle.kts:

  dependencies {
      implementation("com.github.zkmopro:mopro-kotlin-package:Tag") // Or change to your own URL
  }

Replace Tag with the desired release version, e.g. v0.1.0. See the JitPack page for available versions.

Note: If you're using an Android template from mopro create, comment out these UniFFI dependencies in your build file to prevent duplicate class errors.

  // // Uniffi
  // implementation("net.java.dev.jna:jna:5.13.0@aar")
  // implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")

How to use the package​

Here is an example of how to integrate and use this example package

import uniffi.mopro.generateCircomProof
import uniffi.mopro.verifyCircomProof
import uniffi.mopro.ProofLib

val inputStr = "{\"b\":[\"5\"],\"a\":[\"3\"]}"
val zkeyPath = "/path/to/multiplier2_final.zkey"
val proof = generateCircomProof(zkeyPath, inputStr, ProofLib.ARKWORKS)
val isValid = verifyCircomProof(zkeyPath, proof, ProofLib.ARKWORKS)

Or checkout the test-e2e app.