diff --git a/apps/metrics/topology/src/main/java/org/onlab/onos/metrics/topology/TopologyMetricsService.java b/apps/metrics/topology/src/main/java/org/onlab/onos/metrics/topology/TopologyMetricsService.java
new file mode 100644
index 0000000..cc370fa
--- /dev/null
+++ b/apps/metrics/topology/src/main/java/org/onlab/onos/metrics/topology/TopologyMetricsService.java
@@ -0,0 +1,35 @@
+package org.onlab.onos.metrics.topology;
+
+import java.util.List;
+
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Meter;
+import org.onlab.onos.net.topology.TopologyEvent;
+
+/**
+ * Service interface exported by TopologyMetrics.
+ */
+public interface TopologyMetricsService {
+    /**
+     * Gets the last saved topology events.
+     *
+     * @return the last saved topology events.
+     */
+    public List<TopologyEvent> getEvents();
+
+    /**
+     * Gets the Metrics' Gauge for the last topology event timestamp
+     * (ms from the epoch).
+     *
+     * @return the Metrics' Gauge for the last topology event timestamp
+     * (ms from the epoch)
+     */
+    public Gauge<Long> lastEventTimestampEpochMsGauge();
+
+    /**
+     * Gets the Metrics' Meter for the topology events rate.
+     *
+     * @return the Metrics' Meter for the topology events rate
+     */
+    public Meter eventRateMeter();
+}