Sample Code

C# Sample Client:

using GraphQL;
using GraphQL.Client.Http;
using GraphQL.Client.Serializer.SystemTextJson;

class Program
{
    static async Task Main(string[] args)
    {
        string apiUrl = "https://graph-prod-sandbox.liv.championdata.io/graphql";
        string apiKey = "YOUR_API_KEY";

        // create the graphql client
        var graphQLClient = new GraphQLHttpClient(apiUrl, new SystemTextJsonSerializer());
        graphQLClient.HttpClient.DefaultRequestHeaders.Add("x-api-key", apiKey);

        // create a query for all players
        var playersRequest = new GraphQLRequest
        {
            Query = @"{
                players {
                    playerId
                    firstName
                    lastName
                    displayName
                    code
                    country {
                        name
                    }
                    dob
                }
            }"
        };

        // fetch the all players data
        var playersResponse = await graphQLClient.SendQueryAsync<PlayersResponse>(playersRequest);

        // create a query for a specific player id
        var playerByIdRequest = new GraphQLRequest
        {
            Query = @"{
                player(playerId: 12) {
                    playerId
                    firstName
                    lastName
                    displayName
                    code
                    country {
                        name
                    }
                    dob
                }
            }"
        };

        // fetch the player data
        var playerByIdResponse = await graphQLClient.SendQueryAsync<PlayerResponse>(playerByIdRequest);

        // create a query for a specific player id, this time using a variable
        var playerWithVarRequest = new GraphQLRequest
        {
            Query = @"
    query getPlayer($playerId: Int) {
        player(playerId: $playerId) {
            playerId
            firstName
            lastName
            displayName
            code
            country {
                name
            }
            dob
        }
    }",
            OperationName = "getPlayer",
            Variables = new
            {
                playerId = 12
            }
        };

        // fetch the player data
        var playerWithVarResponse = await graphQLClient.SendQueryAsync<PlayerResponse>(playerWithVarRequest);
    }

    public class PlayersResponse
    {
        public List<Player> players { get; set; }
    }

    public class PlayerResponse
    {
        public Player player { get; set; }
    }

    public class Player
    {
        public int playerId { get; set; }
        public string firstName { get; set; }
        public string lastName { get; set; }
        public string displayName { get; set; }
        public Country country { get; set; }
    }

    public class Country
    {
        public string name { get; set; }
    }
}

Node.js Sample Client:

const axios = require('axios');

const apiUrl =
  'https://graph-prod-sandbox.liv.championdata.io/graphql';
const apiKey = 'YOUR_API_KEY';

async function executeQuery(query, variables) {
  try {
    const response = await axios.post(
      apiUrl,
      {
        query,
        variables: JSON.stringify(variables),
      },
      {
        headers: {
          'x-api-key': apiKey,
        },
      }
    );

    console.log(response.data);
  } catch (error) {
    console.error(error);
  }
}

// Query: Get list of players
const playersQuery = `
  {
    players {
      playerId
      firstName
      lastName
      displayName
      code
      country {
        name
      }
      dob
    }
  }
`;

// Query: Get player details by ID
const playerQuery = `
  query($playerId: Int) {
    player(playerId: $playerId) {
      playerId
      firstName
      lastName
      displayName
      code
      country {
        name
      }
      dob
    }
  }
`;

// Execute queries
executeQuery(playersQuery);
executeQuery(playerQuery, { playerId: 12 });

Make sure to replace "YOUR_API_KEY" with your API key.

These sample clients use client libraries (GraphQL.Client in C#, axios in Node.js) to send POST requests to the GraphQL API endpoint. The API key is added to the request headers as "x-api-key" for authentication. The queries are sent as JSON payloads, and the responses are printed to the console.

Please note that these examples are meant to serve as a starting point and may need modifications based on your specific requirements or the libraries and frameworks you're using in your project.