The backend your multiplayer game needs.

$ curl -X POST https://api.gsb.dev/v1/leaderboards/global/scores \
  -H "Authorization: Bearer $GSB_KEY" \
  -d '{"player_id": "p_42", "score": 9001}'

HTTP/1.1 200 OK
{
  "rank": 7,
  "score": 9001,
  "board": "global"
}

import { GSBClient } from "@supercraft/gsb";

const gsb = GSBClient.forPlayer(
  "https://api.gsb.dev", "proj_...", "env_...", process.env.GSB_KEY,
);

const auth = await gsb.loginAnonymous();
await gsb.submitScore("global", auth.player_id, 9001);

const top = await gsb.getTop("global", 10);
console.log(`#${top[0].rank} ${top[0].player_id}`);

using Supercraft.GSB;

var gsb = GSBClient.ForPlayer(
    "https://api.gsb.dev", "proj_...", "env_...", apiKey);

var auth = await gsb.LoginAnonymousAsync();
await gsb.SubmitScoreAsync("global", auth.player_id, 9001);

var top = await gsb.GetTopAsync("global", 10);
Debug.Log($"#{top[0].rank} {top[0].player_id}");

# Autoload GSB once via Project Settings → Autoload
GSB.init_player("https://api.gsb.dev", "proj_...", "env_...", api_key)

var auth = await GSB.login_anonymous()
await GSB.submit_score("global", auth.player_id, 9001.0)

var top = await GSB.get_top("global", 10)
print("#%d %s" % [top[0].rank, top[0].player_id])

-- Server Script in ServerScriptService
local GSB = require(game.ServerScriptService.GSB)
local gsb = GSB.init("proj_...", "YOUR_SERVER_TOKEN", "env_...")

game.Players.PlayerAdded:Connect(function(player)
    local record = gsb:VerifyPlayer(player.UserId)
    gsb:SubmitScore("global", record.player_id, 9001)

    local top = gsb:GetLeaderboardTop("global", 10)
    print(string.format("#%d %s", top[1].rank, top[1].player_id))
end)