diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..47a531e
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,116 @@
+name: CI
+
+on:
+  pull_request:
+    branches: [master]
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  GRADLE_OPTS: -Dorg.gradle.jvmargs=-Xmx6g
+
+jobs:
+  android:
+    name: Android
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-java@v4
+        with:
+          distribution: zulu
+          java-version: 21
+
+      - uses: gradle/actions/setup-gradle@v4
+
+      # secrets.properties is gitignored, but the Secrets Gradle plugin fails without it.
+      # Real ad unit ids fall back to test ids in core:ui, so placeholders are enough.
+      - name: Create stub secrets.properties
+        run: |
+          cat > secrets.properties <<'EOF'
+          MAPS_API_KEY=ci-placeholder
+          ADS_ID_KEY=ca-app-pub-3940256099942544~3347511713
+          METAN_ECOGAS_API=https://example.com/
+          GITHUB_BASE_URL=https://example.com/
+          EOF
+
+      # google-services.json is gitignored; the Google Services plugin only needs a file
+      # with matching package names to build, so CI uses a stub without real keys.
+      - name: Create stub google-services.json
+        run: |
+          cat > app/google-services.json <<'EOF'
+          {
+            "project_info": {
+              "project_number": "000000000000",
+              "project_id": "metanmobile-ci",
+              "storage_bucket": "metanmobile-ci.appspot.com"
+            },
+            "client": [
+              {
+                "client_info": {
+                  "mobilesdk_app_id": "1:000000000000:android:0000000000000000",
+                  "android_client_info": { "package_name": "com.ngapp.metanmobile" }
+                },
+                "api_key": [{ "current_key": "AIzaSyCI000000000000000000000000000000" }]
+              },
+              {
+                "client_info": {
+                  "mobilesdk_app_id": "1:000000000000:android:0000000000000001",
+                  "android_client_info": { "package_name": "com.ngapp.metanmobile.debug" }
+                },
+                "api_key": [{ "current_key": "AIzaSyCI000000000000000000000000000000" }]
+              }
+            ],
+            "configuration_version": "1"
+          }
+          EOF
+
+      - name: Build
+        run: ./gradlew :app:assembleDebug
+
+      - name: Unit tests
+        run: ./gradlew testDebugUnitTest testAndroidHostTest
+
+      - name: Lint
+        run: ./gradlew lintDebug
+
+      - name: Upload reports
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: android-reports
+          path: '**/build/reports/'
+
+  ios:
+    name: iOS
+    runs-on: macos-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-java@v4
+        with:
+          distribution: zulu
+          java-version: 21
+
+      - uses: gradle/actions/setup-gradle@v4
+
+      # secrets.properties is gitignored, but the Secrets Gradle plugin fails without it.
+      # Real ad unit ids fall back to test ids in core:ui, so placeholders are enough.
+      - name: Create stub secrets.properties
+        run: |
+          cat > secrets.properties <<'EOF'
+          MAPS_API_KEY=ci-placeholder
+          ADS_ID_KEY=ca-app-pub-3940256099942544~3347511713
+          METAN_ECOGAS_API=https://example.com/
+          GITHUB_BASE_URL=https://example.com/
+          EOF
+
+      - name: Compile shared code for iOS
+        run: ./gradlew :composeApp:compileKotlinIosSimulatorArm64
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index e20db57..0d88769 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -100,6 +100,9 @@ dependencies {
     // Firebase Performance still uses lite generated protobuf messages at runtime. This was
     // previously brought in transitively by the Android-only DataStore proto module.
     implementation(libs.protobuf.kotlin.lite)
+    // OssLicensesMenuActivity/OssLicensesActivity are declared in this module's manifest, so the
+    // library has to be on app's own compile classpath (core:ui only has it as implementation).
+    implementation(libs.google.oss.licenses)
 
     implementation(projects.core.analytics)
     implementation(projects.core.common)