Initial Kotlin port of the Python A2UI SDK.

agent_sdks/kotlin/.gitignore

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+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# AWS User-specific
+.idea/**/aws.xml
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+# .idea/artifacts
+# .idea/compiler.xml
+# .idea/jarRepositories.xml
+# .idea/modules.xml
+# .idea/*.iml
+# .idea/modules
+# *.iml
+# *.ipr
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# SonarLint plugin
+.idea/sonarlint/
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
+### Gradle template
+.gradle
+**/build/
+!src/**/build/
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar
+
+# Avoid ignore Gradle wrappper properties
+!gradle-wrapper.properties
+
+# Cache of project
+.gradletasknamecache
+
+# Eclipse Gradle plugin generated files
+# Eclipse Core
+.project
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+
+### Kotlin template
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+replay_pid*
+

agent_sdks/kotlin/build.gradle.kts

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+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+plugins {
+  kotlin("jvm") version "2.1.10"
+  kotlin("plugin.serialization") version "2.1.10"
+  id("java-library")
+  id("com.ncorti.ktfmt.gradle") version "0.19.0"
+  id("org.jetbrains.kotlinx.kover") version "0.9.1"
+}
+
+ktfmt {
+  googleStyle()
+}
+
+version = "0.1.0"
+group = "com.google.a2ui"
+
+kotlin {
+  jvmToolchain(21)
+}
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  api("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3")
+  implementation("com.networknt:json-schema-validator:1.5.1")
+  implementation("com.fasterxml.jackson.core:jackson-databind:2.17.2")
+
+  // Core Dependencies
+  api("com.google.adk:google-adk:0.9.0")
+  api("com.google.adk:google-adk-a2a:0.9.0")
+  api("io.github.a2asdk:a2a-java-sdk-client:1.0.0.Alpha3")
+  api("com.google.genai:google-genai:1.43.0")
+
+  testImplementation(kotlin("test"))
+  testImplementation("io.mockk:mockk:1.13.11")
+}
+
+tasks.test {
+  useJUnitPlatform()
+}
+
+val copySpecs by tasks.registering(Copy::class) {
+  val repoRoot = projectDir.parentFile.parentFile
+
+  from(File(repoRoot, "specification/v0_8/json/server_to_client.json")) {
+    into("com/google/a2ui/assets/0.8")
+  }
+  from(File(repoRoot, "specification/v0_8/json/standard_catalog_definition.json")) {
+    into("com/google/a2ui/assets/0.8")
+  }
+
+  from(File(repoRoot, "specification/v0_9/json/server_to_client.json")) {
+    into("com/google/a2ui/assets/0.9")
+  }
+  from(File(repoRoot, "specification/v0_9/json/common_types.json")) {
+    into("com/google/a2ui/assets/0.9")
+  }
+  from(File(repoRoot, "specification/v0_9/json/basic_catalog.json")) {
+    into("com/google/a2ui/assets/0.9")
+  }
+
+  into(layout.buildDirectory.dir("generated/resources/specs"))
+}
+
+sourceSets {
+  main {
+    resources {
+      srcDir(copySpecs)
+    }
+  }
+}

agent_sdks/kotlin/gradle/wrapper/gradle-wrapper.properties

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+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.0-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists