How can I set up Flow (JS type checker) to work on client and server side in a full JS stack?

Is there a way to set up a single instance/installation of Flow, the JavaScript static type checker, to work on both the client side and server side? Obviously this assumes something like Express on the server.

I suppose the more generalized version of this question is how you can set up a project to share NPM modules between the client and server side of an application.

via Captain Stack