diff --git a/compos/composd/aidl/Android.bp b/compos/composd/aidl/Android.bp
new file mode 100644
index 0000000..90c0de0
--- /dev/null
+++ b/compos/composd/aidl/Android.bp
@@ -0,0 +1,21 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+aidl_interface {
+    name: "android.system.composd",
+    srcs: ["android/system/composd/*.aidl"],
+    // TODO: Make this stable when the APEX becomes updatable.
+    unstable: true,
+    backend: {
+        java: {
+            apex_available: ["//apex_available:platform"],
+        },
+        rust: {
+            enabled: true,
+            apex_available: [
+                "com.android.compos",
+            ],
+        },
+    },
+}
diff --git a/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl b/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl
new file mode 100644
index 0000000..0dd5b6f
--- /dev/null
+++ b/compos/composd/aidl/android/system/composd/IIsolatedCompilationService.aidl
@@ -0,0 +1,21 @@
+/*
+ * Copyright 2021 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.
+ */
+package android.system.composd;
+
+interface IIsolatedCompilationService {
+    // TODO: Add real methods
+    void doSomething();
+}