diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index b0570fd..d78de75 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -164,7 +164,7 @@
         BiometricAcquired biometric_acquired = 87;
         BiometricAuthenticated biometric_authenticated = 88;
         BiometricErrorOccurred biometric_error_occurred = 89;
-        // Atom number 90 is available for use.
+        UiEventReported ui_event_reported = 90;
         BatteryHealthSnapshot battery_health_snapshot = 91;
         SlowIo slow_io = 92;
         BatteryCausedShutdown battery_caused_shutdown = 93;
@@ -3266,6 +3266,21 @@
 }
 
 /**
+ * Atom for simple logging of user interaction and impression events, such as "the user touched
+ * this button" or "this dialog was displayed".
+ * Keep the UI event stream clean: don't use for system or background events.
+ * Log using the UiEventLogger wrapper - don't write with the StatsLog API directly.
+ */
+message UiEventReported {
+    // The event_id.
+    optional int32 event_id = 1;
+    // The event's source or target uid and package, if applicable.
+    // For example, the package posting a notification, or the destination package of a share.
+    optional int32 uid = 2 [(is_uid) = true];
+    optional string package_name = 3;
+}
+
+/**
  * Logs when a biometric acquire event occurs.
  *
  * Logged from:
diff --git a/core/java/com/android/internal/logging/UiEvent.java b/core/java/com/android/internal/logging/UiEvent.java
new file mode 100644
index 0000000..0407b07
--- /dev/null
+++ b/core/java/com/android/internal/logging/UiEvent.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2019 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.logging;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.RetentionPolicy.SOURCE;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+@Retention(SOURCE)
+@Target(FIELD)
+public @interface UiEvent {
+    /** An explanation, suitable for Android analysts, of the UI event that this log represents. */
+    String doc();
+}
diff --git a/core/java/com/android/internal/logging/UiEventLogger.java b/core/java/com/android/internal/logging/UiEventLogger.java
new file mode 100644
index 0000000..cca97f6
--- /dev/null
+++ b/core/java/com/android/internal/logging/UiEventLogger.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2019 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.logging;
+
+/**
+ * Logging interface for UI events. Normal implementation is UiEventLoggerImpl.
+ * For testing, use fake implementation UiEventLoggerFake.
+ *
+ * See go/sysui-event-logs and UiEventReported atom in atoms.proto.
+ */
+public interface UiEventLogger {
+    /** Put your Event IDs in enums that implement this interface, and document them using the
+     * UiEventEnum annotation.
+     * Event IDs must be globally unique. This will be enforced by tooling (forthcoming).
+     * OEMs should use event IDs above 100000.
+     */
+    interface UiEventEnum {
+        int getId();
+    }
+    /**
+     * Log a simple event, with no package or instance ID.
+     */
+    void log(UiEventEnum eventID);
+}
diff --git a/core/java/com/android/internal/logging/UiEventLoggerImpl.java b/core/java/com/android/internal/logging/UiEventLoggerImpl.java
new file mode 100644
index 0000000..e64fba2
--- /dev/null
+++ b/core/java/com/android/internal/logging/UiEventLoggerImpl.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2019 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.logging;
+
+import android.util.StatsLog;
+
+/**
+ * Standard implementation of UiEventLogger, writing to StatsLog.
+ *
+ * See UiEventReported atom in atoms.proto for more context.
+ */
+public class UiEventLoggerImpl implements UiEventLogger {
+    /**
+     * Log a simple event, with no package or instance ID.
+     */
+    @Override
+    public void log(UiEventEnum event) {
+        final int eventID = event.getId();
+        if (eventID > 0) {
+            StatsLog.write(StatsLog.UI_EVENT_REPORTED, eventID, 0, null);
+        }
+    }
+}
diff --git a/core/java/com/android/internal/logging/testing/UiEventLoggerFake.java b/core/java/com/android/internal/logging/testing/UiEventLoggerFake.java
new file mode 100644
index 0000000..92e9bbb
--- /dev/null
+++ b/core/java/com/android/internal/logging/testing/UiEventLoggerFake.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2019 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.logging.testing;
+
+import com.android.internal.logging.UiEventLogger;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+/**
+ * Fake logger that queues up logged events for inspection.
+ *
+ * @hide.
+ */
+public class UiEventLoggerFake implements UiEventLogger {
+    /**
+     * Immutable data class used to record fake log events.
+     */
+    public class FakeUiEvent {
+        public final int eventId;
+        public final int uid;
+        public final String packageName;
+
+        public FakeUiEvent(int eventId, int uid, String packageName) {
+            this.eventId = eventId;
+            this.uid = uid;
+            this.packageName = packageName;
+        }
+    }
+
+    private Queue<FakeUiEvent> mLogs = new LinkedList<FakeUiEvent>();
+
+    @Override
+    public void log(UiEventEnum event) {
+        final int eventId = event.getId();
+        if (eventId > 0) {
+            mLogs.offer(new FakeUiEvent(eventId, 0, null));
+        }
+    }
+
+    public Queue<FakeUiEvent> getLogs() {
+        return mLogs;
+    }
+}