diff -r fbd3585af53e -r 0ff0059f2ec3 src/net/java/otr4j/OtrEngineHost.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/net/java/otr4j/OtrEngineHost.java	Sun Dec 05 18:43:51 2010 +0100
@@ -0,0 +1,31 @@
+/*
+ * otr4j, the open source java otr library.
+ *
+ * Distributable under LGPL license.
+ * See terms of license at gnu.org.
+ */
+package net.java.otr4j;
+
+import java.security.KeyPair;
+
+import net.java.otr4j.session.SessionID;
+
+/**
+ * 
+ * This interface should be implemented by the host application. It is required
+ * for otr4j to work properly.
+ * 
+ * @author George Politis
+ * 
+ */
+public abstract interface OtrEngineHost {
+	public abstract void injectMessage(SessionID sessionID, String msg);
+
+	public abstract void showWarning(SessionID sessionID, String warning);
+
+	public abstract void showError(SessionID sessionID, String error);
+
+	public abstract OtrPolicy getSessionPolicy(SessionID sessionID);
+	
+	public abstract KeyPair getKeyPair(SessionID sessionID);
+}