Hey @chmelevskij!

I believe that it is possible to do what you want! Looking at the schema, it looks like the connection between Repositories and Languages does have an “edge type” that includes the number of bytes written in that language in the particular repository. Here’s the query that I’m using for Facebook’s React Repository:

{
  repository(owner: "facebook", name: "react") {
    languages(first: 50, orderBy: {field: SIZE, direction: DESC}) {
      edges {
        size
        node {
          name
        }
      }
    }
  }
}

This gives me the same results as I can see in the REST API, sorted by the number of bytes in each language in descending order. 

Let me know if I’ve misread, and have a great day!