Lighthouse lets you build a GraphQL API for your Rails app primarily through schema (SDL) and server-side directives — @all, @find, @paginate, @hasMany, @belongsTo, @whereConditions, @orderBy, @field, @auth and more — instead of hand-writing a resolver for every field. It is a Ruby adaptation of the PHP Lighthouse library (nuwave/lighthouse) built on top of graphql-ruby, with first-class Apollo Federation support so a Rails service can act as a subgraph.