Package ProGuard rules in Android AAR

CHANGELOG.md

@@ -7,6 +7,9 @@ for the Linux x64 and Darwin x64 platforms.
 
 ## Unreleased Changes
 
+### Fixed
+- Include ProGuard/R8 rules in the Android AAR to preserve classes and constructors used by JNI. (#215)
+
 ## [4.5.1] - 2026-10-15
 ### Changed
 - Releases are signed with a new key, and the release process was updated. (#216, #217)

build.gradle

@@ -167,7 +167,7 @@ task androidJar(type: Jar) {
         include 'android-arm64/**'
         include 'META-INF/**'
     }
-    
+
     duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 
     manifest {
@@ -200,6 +200,10 @@ task androidAar(type: Zip) {
     archiveBaseName = 'h3-android'
     archiveVersion = project.version
     archiveExtension = 'aar'
+
+    from('src/main/proguard/h3-android.pro') {
+        rename { 'proguard.txt' }
+    }
 
     // Map android-arm to armeabi-v7a (32-bit ARM)
     from('src/main/resources/android-arm') {

src/main/proguard/h3-android.pro

@@ -0,0 +1,7 @@
+# These classes and constructors are looked up by name from the JNI layer.
+-keep class com.uber.h3core.util.LatLng {
+    public <init>(double, double);
+}
+-keep class com.uber.h3core.exceptions.H3Exception {
+    public <init>(int);
+}