diff --git a/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java
new file mode 100644
index 0000000..a87eb65
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java
@@ -0,0 +1,84 @@
+package net.onrc.onos.api.flowmanager;
+
+import java.util.Collection;
+import java.util.EventListener;
+
+/**
+ * An interface class for flow manager. The role of the flow manager is to
+ * manage a set of Match-Action entries based on the specified IFlow objects.
+ * <p>
+ * It compiles accepted IFlow objects to Match-Action entries by calculating the
+ * match-action operation phases and allocating resources based on the
+ * constrains described in the IFlow objects, and executes calculated phases
+ * using Match-Action Service.
+ * <p>
+ * TODO: add more getter with filter for IFlow objects.
+ */
+public interface FlowManagerService {
+    /**
+     * Adds IFlow object, calculates match-action plan and executes it.
+     *
+     * @param flow IFlow object to be added
+     * @return true if succeeded, false otherwise
+     */
+    boolean addFlow(Flow flow);
+
+    /**
+     * Removes IFlow object, calculates match-action plan and executes it.
+     *
+     * @param id ID for IFlow object to be removed
+     * @return true if succeeded, false otherwise
+     */
+    boolean removeFlow(FlowId id);
+
+    /**
+     * Gets IFlow object.
+     *
+     * @param id ID of IFlow object
+     * @return IFlow object if found, null otherwise
+     */
+    Flow getFlow(FlowId id);
+
+    /**
+     * Gets All IFlow objects.
+     *
+     * @return the collection of IFlow objects
+     */
+    Collection<Flow> getFlows();
+
+    /**
+     * Executes batch operation of IFlow object.
+     *
+     * @param ops flow operations to be executed
+     * @return true if succeeded, false otherwise
+     */
+    boolean executeBatch(FlowBatchOperation ops);
+
+    /**
+     * Sets a conflict detection policy.
+     *
+     * @param policy ConflictDetectionPolicy object to be set
+     */
+    void setConflictDetectionPolicy(ConflictDetectionPolicy policy);
+
+    /**
+     * Gets the conflict detection policy.
+     *
+     * @return ConflictDetectionPolicy object being applied currently
+     */
+    ConflictDetectionPolicy getConflictDetectionPolicy();
+
+    /**
+     * Adds event listener to this service.
+     *
+     * @param listener EventListener to be added
+     */
+    void addEventListener(EventListener listener);
+
+    /**
+     * Removes event listener from this service.
+     *
+     * @param listener EventListener to be removed
+     */
+    void removeEventListener(EventListener listener);
+}