diff --git a/.github/workflows/CODECOV.yml b/.github/workflows/CODECOV.yml
new file mode 100644
index 0000000..08a5cc7
--- /dev/null
+++ b/.github/workflows/CODECOV.yml
@@ -0,0 +1,36 @@
+name: CODECOV
+# https://docs.github.com/en/actions/learn-github-actions/expressions
+
+on:
+  push:
+    branches: [ main, 'release/**' ]
+  pull_request:
+    branches: [ main, 'release/**' ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+env:
+  CI: true
+
+  JAVA_VERSION: 17
+  JAVA_DISTRIBUTION: zulu
+
+jobs:
+  test:
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - { uses: actions/checkout@v4 }
+      - { name: Use Node.js 20.x, uses: actions/setup-node@v4, with: { node-version: 20.x } }
+      - { name: Setup Deno, uses: denoland/setup-deno@v1, with: { deno-version: "1.44.4" } }
+      - { name: Replace gradle wrapper, run: "sed 's/-all/-bin/g' gradle/wrapper/gradle-wrapper.properties > gradle/wrapper/gradle-wrapper.properties.bak; cp gradle/wrapper/gradle-wrapper.properties.bak gradle/wrapper/gradle-wrapper.properties" }
+      - { name: Set up JDK, uses: actions/setup-java@v4, with: { distribution: "${{ env.JAVA_DISTRIBUTION }}", java-version: "${{ env.JAVA_VERSION }}" } }
+      - { name: Prepare Gradle, uses: gradle/actions/setup-gradle@d9c87d481d55275bb5441eef3fe0e46805f9ef70 } # https://github.com/gradle/actions/releases/tag/v3.5.0
+      - { name: Start gradle, run: ./gradlew }
+      - { name: Code coverage, run: ./gradlew koverXmlReport }
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v4.0.1
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
\ No newline at end of file
diff --git a/.github/workflows/TEST.yml b/.github/workflows/TEST.yml
index 4e5caa9..56feda5 100644
--- a/.github/workflows/TEST.yml
+++ b/.github/workflows/TEST.yml
@@ -30,7 +30,7 @@ jobs:
           #- { outputKey: testJs, os: ubuntu-latest, testTask: "wasmBrowserTest", buildTasks: "jsNodeTest jsBrowserTest" }
           - { outputKey: testJs, os: ubuntu-latest, testTask: "wasmBrowserTest", buildTasks: "jsBrowserTest jsDenoTest" }
           - { outputKey: testAndroid, os: ubuntu-latest, enableAndroid: true }
-          - { outputKey: testJvmMacos, os: macos-latest, testTask: jvmTest }
+          - { outputKey: testJvmMacos, os: macos-latest, testTask: jvmTest apiCheck }
           - { outputKey: testJvmLinux, os: ubuntu-latest, testTask: jvmTest, precompileTask: compileTestKotlinJvm, enableKotlinNative: true, enableSandbox: true, e2e: true }
           - { outputKey: testJvmWindows, os: windows-latest, testTask: jvmTest, precompileTask: compileTestKotlinJvm }
     #if: ${{ needs.changes.outputs[matrix.outputKey] == 'true' }}
diff --git a/build.gradle.kts b/build.gradle.kts
index 6e98412..65e859a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -17,6 +17,8 @@ import java.util.concurrent.*
 plugins {
     kotlin("multiplatform") version "2.0.0"
     id("com.android.library") version "8.2.2"
+    id("org.jetbrains.kotlinx.kover") version "0.8.3" apply false
+    id("org.jetbrains.kotlinx.binary-compatibility-validator") version "0.16.2"
     id("org.jetbrains.dokka") version "1.9.20"
     `maven-publish`
     signing
@@ -1122,6 +1124,7 @@ allprojects {
 
 subprojects {
     plugins.apply("org.jetbrains.dokka")
+    plugins.apply("org.jetbrains.kotlinx.kover")
 }
 
 allprojects {
@@ -1130,3 +1133,7 @@ allprojects {
         offlineMode.set(true)
     }
 }
+
+apiValidation {
+    ignoredProjects.addAll(listOf(rootProject.name))
+}
diff --git a/korlibs-simple/api/android/korlibs-simple.api b/korlibs-simple/api/android/korlibs-simple.api
new file mode 100644
index 0000000..38fde02
--- /dev/null
+++ b/korlibs-simple/api/android/korlibs-simple.api
@@ -0,0 +1,4 @@
+public final class korlibs/simple/Simple {
+	public fun <init> ()V
+}
+
diff --git a/korlibs-simple/api/jvm/korlibs-simple.api b/korlibs-simple/api/jvm/korlibs-simple.api
new file mode 100644
index 0000000..38fde02
--- /dev/null
+++ b/korlibs-simple/api/jvm/korlibs-simple.api
@@ -0,0 +1,4 @@
+public final class korlibs/simple/Simple {
+	public fun <init> ()V
+}
+