diff --git a/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java b/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java
new file mode 100644
index 0000000..1340156
--- /dev/null
+++ b/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2024 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 com.android.internal.ravenwood;
+
+/**
+ * Class to interact with the Ravenwood environment.
+ */
+@android.ravenwood.annotation.RavenwoodKeepWholeClass
+public class RavenwoodEnvironment {
+    private static RavenwoodEnvironment sInstance = new RavenwoodEnvironment();
+
+    private RavenwoodEnvironment() {
+    }
+
+    /**
+     * @return the singleton instance.
+     */
+    public static RavenwoodEnvironment getInstance() {
+        return sInstance;
+    }
+
+    /**
+     * USE IT SPARINGLY! Returns true if it's running on Ravenwood, hostside test environment.
+     *
+     * <p>Using this allows code to behave differently on a real device and on Ravenwood, but
+     * generally speaking, that's a bad idea because we want the test target code to behave
+     * differently.
+     *
+     * <p>This should be only used when different behavior is absolutely needed.
+     *
+     * <p>If someone needs it without having access to the SDK, the following hack would work too.
+     * <code>System.getProperty("java.class.path").contains("ravenwood")</code>
+     */
+    @android.ravenwood.annotation.RavenwoodReplace
+    public boolean isRunningOnRavenwood() {
+        return false;
+    }
+
+    public boolean isRunningOnRavenwood$ravenwood() {
+        return true;
+    }
+}
diff --git a/core/tests/coretests/Android.bp b/core/tests/coretests/Android.bp
index 436ba15..eb3c84a 100644
--- a/core/tests/coretests/Android.bp
+++ b/core/tests/coretests/Android.bp
@@ -260,6 +260,7 @@
         "src/com/android/internal/os/**/*.java",
         "src/com/android/internal/util/**/*.java",
         "src/com/android/internal/power/EnergyConsumerStatsTest.java",
+        "src/com/android/internal/ravenwood/**/*.java",
 
         // Pull in R.java from FrameworksCoreTests-resonly, not from FrameworksCoreTests,
         // to avoid having a dependency to FrameworksCoreTests.
diff --git a/core/tests/coretests/src/com/android/internal/ravenwood/RavenwoodEnvironmentTest.java b/core/tests/coretests/src/com/android/internal/ravenwood/RavenwoodEnvironmentTest.java
new file mode 100644
index 0000000..d1ef61b
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/ravenwood/RavenwoodEnvironmentTest.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2024 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 com.android.internal.ravenwood;
+
+import static junit.framework.TestCase.assertEquals;
+
+import android.platform.test.ravenwood.RavenwoodRule;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class RavenwoodEnvironmentTest {
+    @Rule
+    public final RavenwoodRule mRavenwood = new RavenwoodRule();
+
+    @Test
+    public void testIsRunningOnRavenwood() {
+        assertEquals(RavenwoodRule.isUnderRavenwood(),
+                RavenwoodEnvironment.getInstance().isRunningOnRavenwood());
+    }
+}
diff --git a/ravenwood/texts/ravenwood-annotation-allowed-classes.txt b/ravenwood/texts/ravenwood-annotation-allowed-classes.txt
index e452299..d856f6d 100644
--- a/ravenwood/texts/ravenwood-annotation-allowed-classes.txt
+++ b/ravenwood/texts/ravenwood-annotation-allowed-classes.txt
@@ -1,5 +1,7 @@
 # Only classes listed here can use the Ravenwood annotations.
 
+com.android.internal.ravenwood.*
+
 com.android.internal.display.BrightnessSynchronizer
 com.android.internal.util.ArrayUtils
 com.android.internal.logging.MetricsLogger