WPGraphQL is a plugin that provides an extendable GraphQL schema and API for WordPress sites. It allows you to separate your CMS from your presentation layer.
WPGraphQL offers its own add-on integration plugin to work with FacetWP.
This plugin exposes configured facets through the graph schema. Once registered for a type, a query is available. The payload includes both facet choices and information and a connection to the post type data. This allows for standard GraphQL pagination of the returned data set.