wspb

wspb generates .proto schemas and Protobuf lite sources from Kotlin models by combining an annotation, a KSP processor, and an Android Gradle plugin.

Kotlin model -> @WSProto -> KSP .proto generation -> Android proto source wiring -> protoc Java lite sources

Modules

• wspb-annotation: defines @WSProto
• wspb-processor: KSP processor that generates .proto files
• wspb-gradle-plugin: Android Gradle plugin that wires generated proto directories into the build
• sample-app: example consumer app for integration verification

Planned Public Coordinates

These are the coordinates intended for published releases:

dependencies {
    implementation("io.github.ows3090:wspb-annotation:1.0.1")
    ksp("io.github.ows3090:wspb-processor:1.0.1")
}

plugins {
    id("io.github.ows3090.wspb.proto") version "1.0.1"
}

Quick Start

The example below shows the intended public-consumer setup after the first release is published.

plugins {
    id("com.android.application")
    id("org.jetbrains.kotlin.android")
    id("com.google.devtools.ksp")
    id("io.github.ows3090.wspb.proto") version "1.0.1"
}

dependencies {
    implementation("io.github.ows3090:wspb-annotation:1.0.1")
    ksp("io.github.ows3090:wspb-processor:1.0.1")
}

import com.wonseok.wspb.annotation.WSProto

@WSProto(name = "user_preference")
data class UserData(
    val id: Int,
    val name: String,
)

KSP Options

ksp {
    arg("wspb.proto.packagePath", "proto/com/example/schema")
    arg("wspb.proto.javaPackage", "com.example.schema")
    arg("wspb.processor.verbose", "true")
}

• wspb.proto.packagePath: output subdirectory for generated .proto files
• wspb.proto.javaPackage: option java_package written into generated .proto files
• wspb.processor.verbose: enables processor warning logs

Default values:

• wspb.proto.packagePath = proto/com/wonseok/wspb
• wspb.proto.javaPackage = com.wonseok.wspb
• wspb.processor.verbose = false

Compatibility

Current repo baseline:

• JDK 21
• Kotlin 2.0.21
• KSP 2.0.21-1.0.27
• AGP 8.13.1

These are the versions currently validated in this repository. A broader compatibility policy will be documented after the first public release.

Limitations

• Supported field types are limited to primitives, String, ByteArray, List, Set, and Array
• Custom classes, enums, and nullable-specific mapping are not yet supported
• The generated proto path defaults to the repository package unless overridden with KSP options

Local Development

Inside this repository, the safest verification flow is:

./gradlew :wspb-gradle-plugin:publishToMavenLocal --configure-on-demand
./gradlew :sample-app:assembleDebug
./gradlew :wspb-processor:test
./gradlew spotlessCheck
./gradlew lint

Docs

• Usage Guide
• Contributing