diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java
new file mode 100644
index 0000000..ba9cd1b
--- /dev/null
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/IFlowService.java
@@ -0,0 +1,161 @@
+package net.onrc.onos.ofcontroller.flowmanager;
+
+import java.util.ArrayList;
+
+import net.floodlightcontroller.core.module.IFloodlightService;
+import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowPath;
+import net.onrc.onos.ofcontroller.util.CallerId;
+import net.onrc.onos.ofcontroller.util.DataPathEndpoints;
+import net.onrc.onos.ofcontroller.util.FlowId;
+import net.onrc.onos.ofcontroller.util.FlowPath;
+
+/**
+ * @short Interface for providing Flow Service to other modules.
+ */
+public interface IFlowService extends IFloodlightService {
+    /**
+     * Add a flow.
+     *
+     * Internally, ONOS will automatically register the installer for
+     * receiving Flow Path Notifications for that path.
+     *
+     * @param flowPath the Flow Path to install.
+     * @param flowId the return-by-reference Flow ID as assigned internally.
+     * @param dataPathSummaryStr the data path summary string if the added
+     * flow will be maintained internally, otherwise null.
+     * @return true on success, otherwise false.
+     */
+    boolean addFlow(FlowPath flowPath, FlowId flowId,
+		    String dataPathSummaryStr);
+
+    /**
+     * Delete all previously added flows.
+     *
+     * @return true on success, otherwise false.
+     */
+    boolean deleteAllFlows();
+
+    /**
+     * Delete a previously added flow.
+     *
+     * @param flowId the Flow ID of the flow to delete.
+     * @return true on success, otherwise false.
+     */
+    boolean deleteFlow(FlowId flowId);
+
+    /**
+     * Clear the state for all previously added flows.
+     *
+     * @return true on success, otherwise false.
+     */
+    boolean clearAllFlows();
+
+    /**
+     * Clear the state for a previously added flow.
+     *
+     * @param flowId the Flow ID of the flow to clear.
+     * @return true on success, otherwise false.
+     */
+    boolean clearFlow(FlowId flowId);
+
+    /**
+     * Get a previously added flow.
+     *
+     * @param flowId the Flow ID of the flow to get.
+     * @return the Flow Path if found, otherwise null.
+     */
+    FlowPath getFlow(FlowId flowId);
+
+    /**
+     * Get all previously added flows by a specific installer for a given
+     * data path endpoints.
+     *
+     * @param installerId the Caller ID of the installer of the flow to get.
+     * @param dataPathEndpoints the data path endpoints of the flow to get.
+     * @return the Flow Paths if found, otherwise null.
+     */
+    ArrayList<FlowPath> getAllFlows(CallerId installerId,
+				 DataPathEndpoints dataPathEndpoints);
+
+    /**
+     * Get all installed flows by all installers for given data path endpoints.
+     *
+     * @param dataPathEndpoints the data path endpoints of the flows to get.
+     * @return the Flow Paths if found, otherwise null.
+     */
+    ArrayList<FlowPath> getAllFlows(DataPathEndpoints dataPathEndpoints);
+
+    /**
+     * Get summary of all installed flows by all installers.
+     *
+     * @param flowId: starting flow Id of the range
+     * @param maxFlows: number of flows to return
+     * @return the Flow Paths if found, otherwise null.
+     */
+    ArrayList<IFlowPath> getAllFlowsSummary(FlowId flowId, int maxFlows);
+    
+    /**
+     * Get all installed flows by all installers.
+     *
+     * @return the Flow Paths if found, otherwise null.
+     */
+    ArrayList<FlowPath> getAllFlows();
+
+    /**
+     * Add and maintain a shortest-path flow.
+     *
+     * NOTE: The Flow Path argument does NOT contain all flow entries.
+     * Instead, it contains a single dummy flow entry that is used to
+     * store the matching condition(s).
+     * That entry is replaced by the appropriate entries from the
+     * internally performed shortest-path computation.
+     *
+     * @param flowPath the Flow Path with the endpoints and the match
+     * conditions to install.
+     * @return the added shortest-path flow on success, otherwise null.
+     */
+    public FlowPath addAndMaintainShortestPathFlow(FlowPath flowPath);
+
+    /**
+     * Store a path flow for measurement purpose.
+     *
+     * NOTE: The Flow Path argument does NOT contain flow entries.
+     *
+     * @param flowPath the Flow Path with the endpoints and the match
+     * conditions to store.
+     * @return the stored shortest-path flow on success, otherwise null.
+     */
+    public FlowPath measurementStorePathFlow(FlowPath flowPath);
+
+    /**
+     * Install path flows for measurement purpose.
+     *
+     * @param numThreads the number of threads to use to install the path
+     * flows.
+     * @return true on success, otherwise false.
+     */
+    public boolean measurementInstallPaths(Integer numThreads);
+
+    /**
+     * Get the measurement time that took to install the path flows.
+     *
+     * @return the measurement time (in nanoseconds) it took to install
+     * the path flows.
+     */
+    public Long measurementGetInstallPathsTimeNsec();
+
+    /**
+     * Get the measurement install time per Flow.
+     *
+     * @return a multi-line string with the following format per line:
+     * ThreadAndTimePerFlow <ThreadId> <TotalThreads> <Time(ns)>
+     */
+    public String measurementGetPerFlowInstallTime();
+
+    /**
+     * Clear the path flows stored for measurement purpose.
+     *
+     * @return true on success, otherwise false.
+     */
+    public boolean measurementClearAllPaths();
+}