Need Three.js export for sculpt tool

I`m developing a react 3d app which sends meshes to a cad system on a server. The cad system makes some calculations on the meshes and sends them back to three in the browser. i would like to have a little sculpt and paint tool in front of this, to upload the painted meshes to the cad system. The developer should know about vertex painting in three, uploading and downloading obj and stl files to three and api requests to and from the cad system. Happy to hear from you!