Converse has a special build called the headless build.
You can generate it yourself by running
npm run build
in the root.
The headless build is a bundle of all the non-UI parts of Converse, and its aim is to provide you with an XMPP library (and application) on which you can build your own UI.
It's also installable with NPM/Yarn as converse-headless-xmpp.
The main distribution of Converse relies on the headless build.