Can specify in launcher configuration extra paths to go on the application classpath:

[app]
 ...
 resources: conf, resources

launch/interface/src/main/java/xsbti/ApplicationID.java

@@ -1,5 +1,7 @@
 package xsbti;
 
+import java.io.File;
+
 public interface ApplicationID
 {
 	public String groupID();
@@ -9,4 +11,7 @@ public interface ApplicationID
 	public String mainClass();
 	public String[] mainComponents();
 	public boolean crossVersioned();
+	
+	/** Files to add to the application classpath. */
+	public File[] classpathExtra();
 }