diff --git a/java/com/android/modules/targetprep/proto/Android.bp b/java/com/android/modules/targetprep/proto/Android.bp
new file mode 100644
index 0000000..2cbe441
--- /dev/null
+++ b/java/com/android/modules/targetprep/proto/Android.bp
@@ -0,0 +1,27 @@
+// Copyright (C) 2022 The Android Open Source Project
+//
+// 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
+//
+//      http://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.
+
+java_library_host {
+    name: "classpath_classes_proto_java",
+    srcs: [
+        "classpath_classes.proto",
+    ],
+    static_libs: [
+        "libprotobuf-java-full",
+    ],
+    proto: {
+        type: "full",
+        canonical_path_from_root: false,
+    },
+}
diff --git a/java/com/android/modules/targetprep/proto/classpath_classes.proto b/java/com/android/modules/targetprep/proto/classpath_classes.proto
new file mode 100644
index 0000000..47de384
--- /dev/null
+++ b/java/com/android/modules/targetprep/proto/classpath_classes.proto
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+syntax = "proto3";
+
+option java_package = "com.android.modules.proto";
+
+enum Classpath {
+  UNKNOWN = 0;
+  BOOTCLASSPATH = 1;
+  SYSTEMSERVERCLASSPATH = 2;
+  STANDALONE_SYSTEMSERVER_JARS = 4;
+}
+
+message SharedLibrary {
+  string name = 1;
+  string type = 2;
+  string version = 3;
+  repeated string paths = 4;
+}
+
+message Apk {
+  string path = 1;
+}
+
+message Jar {
+  string path = 1;
+  Classpath classpath = 2;
+}
+
+message ClasspathEntry {
+  oneof entry_type {
+    Jar jar = 1;
+    SharedLibrary library = 2;
+    Apk apk = 3;
+  }
+
+  repeated string classes = 4;
+}
+
+message ClasspathClassesDump {
+  repeated ClasspathEntry entries = 1;
+}