Under the hood Wertik-js uses Apollo GraphQL server for Graphql Implementation, we selected Apollo Graphql server due to its popularity and features. Please see this file https://github.com/Uconnect-Technologies/wertik-js/tree/master/src/framework/graphql/index.ts where the GraphQL is added.
Currently we donot have direct implementation for GraphQL, You can only use GraphQL by using with custom modules, Please see custom modules page for more details.
If you have any suggestions, bugs or feature request you can create a new issue
We will be happy to assist you with your issue.