Converse has a special build called the headless build.
You can generate it yourself by running make dist/converse-headless.js
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.
The main distribution of Converse relies on the headless build.
The file src/headless/headless.js is used to determine which plugins are included in the build.