Render the viewer node

I’m trying to render a Youtube channel intro that is entirely in the compositer and with nodes. However, when I render the animation, it just shows a black screen as the video, because it is rendering the renderlayer (that is empty). How to I instruct blender to render an animation from the viewer node?

The “composite” node is the one that feeds your composite chain back into the render buffer. Make sure you have one and that it is connected to the same node as the viewer you’re previewing with. Or use a flie output node instead, if your prefer (again, same connection as your viewer).

Thank you!