There is, but it's an undocumented internal API subject to change at any time. Generating DRL is the recommended way to create rules in this case.

From: Leonardo Gomes <leonardo.f.gomes@gmail.com>
To: rules-users@lists.jboss.org
Sent: Mon, October 19, 2009 8:56:14 AM
Subject: [rules-users] Creating rules from an UI

Hi Guys,

I have an UI that allows users to create rules in admin interface of my application. I'm thinking about generating drl text out of the UI state (I'd have an object model that would be populated by it), but was wondering if there would be a way to programmatically create the rules instead of having this object->drl step.

Advice is welcome!

Thanks in advance.

Leo.