import 'package:graphql_parser/graphql_parser.dart'; final String INPUT = ''' { project(name: "GraphQL") { tagline } } ''' .trim(); main() { var tokens = scan(INPUT); var parser = new Parser(tokens); var doc = parser.parseDocument(); var operation = doc.definitions.first as OperationDefinitionContext; var projectField = operation.selectionSet.selections.first.field; print(projectField.fieldName.name); // project print(projectField.arguments.first.name); // name print(projectField.arguments.first.valueOrVariable.value.value); // GraphQL var taglineField = projectField.selectionSet.selections.first.field; print(taglineField.fieldName.name); // tagline }