diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IPathComputationService.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IPathComputationService.java
new file mode 100644
index 0000000..1bc0be1
--- /dev/null
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IPathComputationService.java
@@ -0,0 +1,51 @@
+package net.onrc.onos.ofcontroller.flowmanager;
+
+import net.onrc.onos.ofcontroller.topology.TopologyElement;
+import net.onrc.onos.ofcontroller.util.FlowPath;
+
+/**
+ * Interface for providing Path Computation Service to other modules.
+ */
+public interface IPathComputationService {
+    /**
+     * Receive a notification that a Flow is added.
+     *
+     * @param flowPath the flow that is added.
+     */
+    void notificationRecvFlowAdded(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Flow is removed.
+     *
+     * @param flowPath the flow that is removed.
+     */
+    void notificationRecvFlowRemoved(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Flow is updated.
+     *
+     * @param flowPath the flow that is updated.
+     */
+    void notificationRecvFlowUpdated(FlowPath flowPath);
+
+    /**
+     * Receive a notification that a Topology Element is added.
+     *
+     * @param topologyElement the Topology Element that is added.
+     */
+    void notificationRecvTopologyElementAdded(TopologyElement topologyElement);
+
+    /**
+     * Receive a notification that a Topology Element is removed.
+     *
+     * @param topologyElement the Topology Element that is removed.
+     */
+    void notificationRecvTopologyElementRemoved(TopologyElement topologyElement);
+
+    /**
+     * Receive a notification that a Topology Element is updated.
+     *
+     * @param topologyElement the Topology Element that is updated.
+     */
+    void notificationRecvTopologyElementUpdated(TopologyElement topologyElement);
+}