Code Using GraphQL

import ballerina/graphql;
import ballerina/io;
 
type Response record {
    record { string hello; } data;
};
 
public function main() returns error? {
    graphql:Client helloClient = check new ("localhost:9090/graphql");
    string document = "{ hello }";
    Response response = check helloClient->execute(document);
    io:println(response.data.hello);
}

import ballerina/graphql;
 
service /graphql on new graphql:Listener(9090) {
    resource function get hello() returns string {
        return "Hello, world!";
    }
}