System uses GraphQL to access the API, which is an alternative for a more widespread REST model. GraphQL brings improvements in the form of greater clarity, typology, and a reduced number of queries. GraphQL is an application layer level query language. The server interprets the query string and returns a response with the data in the required format. It provides a comprehensive and clear description of the data in the API, giving client applications the ability to request exactly the data they need.
GraphQL uses two types of operations. Query operations are used to read data. Mutations are used to change data. Individual query and mutation operations are sent in the POST endpoint request.
https://system2.netrex.cz/api/graphql.php
The endpoint remains constant regardless of the operation being performed. More about GraphQL in this article. More about the transition from REST to GraphQL in this article.