Game Hub SDK

The SDK is a small JavaScript file that lets your game talk to the hub: receive the language and player info, and report the start and end of each run so scores get saved.

Include the SDK

html

<script src="https://play.monlabs.fun/sdk/gamehub-sdk.js"></script>

Use the full URL as above – your build is served from a different domain than the hub. The SDK creates a global window.GameHub.

Functions

Function	When to call	Result
`GameHub.init()`	Once, when the game has loaded	`Promise<{ locale, player, canSubmitScore, standalone }>`
`GameHub.gameStart()`	A new run starts – best called on the player's first input	The hub starts timing the run
`GameHub.gameOver(score, { leaderboard })`	The run ends	The hub submits the score (integer ≥ 0) to leaderboard `leaderboard` (default `"default"`)
`GameHub.showRewardedAd()`	The player chooses to watch an ad for a reward	`Promise<{ shown, rewarded, reason? }>` – only reward when `rewarded === true`
`GameHub.showInterstitialAd()`	Between levels	`Promise<{ shown }>`
`GameHub.on(event, callback)`	Listen to the hub	See Events

`init` data

{
  protocolVersion: 1,
  standalone: false,      // true when the game is opened directly, not through the hub
  locale: "en",           // "vi" | "en"
  player: { displayName: "ha_pham" } | null,
  canSubmitScore: true    // false = the player hasn't connected a wallet, scores won't be saved
}

When canSubmitScore is false, show a small hint such as "Connect your wallet on Game Hub to save your score" – the game still plays normally.

Events

Event	When
`init`	Sent again when the player connects a wallet or switches language while on the game page – update your text and the save hint
`scoreResult`	After `gameOver()`: the result of saving the score
`pause` / `resume`	The hub asks the game to pause / continue (for interstitial ads)

`scoreResult` data

{
  saved: true,              // false = the score was NOT recorded
  code: null,               // when saved = false: an error code, see the Leaderboards page
  message: "New best: 1,696 points! You're rank #3",  // already in the player's language
  score: 1696, best: 1696, rank: 3, isNewBest: true    // only when saved = true
}

Always show message to the player

Especially when saved: false – don't let players think their score was saved. Error codes are listed in Leaderboards & anti-cheat.

Game Hub doesn't show ads yet: showRewardedAd() returns { shown: false, rewarded: false } and showInterstitialAd() returns { shown: false }. Make sure the game plays normally without ads – for example, hide the "Watch an ad for a reward" button when shown is false.

Full example

html

<script src="https://play.monlabs.fun/sdk/gamehub-sdk.js"></script>
<script>
  let score = 0;
  let playing = false;
  const note = document.getElementById("save-note");
  const result = document.getElementById("result");

  function applyHub(hub) {
    document.documentElement.lang = hub.locale;
    note.hidden = hub.standalone || hub.canSubmitScore;
  }

  GameHub.init().then(applyHub);
  GameHub.on("init", applyHub); // signed in / switched language mid-game
  GameHub.on("scoreResult", (r) => {
    result.textContent = r.message;
    result.className = r.saved ? "ok" : "error";
  });
  GameHub.on("pause", () => pauseGame());

  function onFirstInput() {
    if (!playing) {
      playing = true;
      score = 0;
      GameHub.gameStart();
    }
  }

  function onGameOver() {
    playing = false;
    GameHub.gameOver(score);
  }
</script>

Test before submitting for review

After uploading, click Test play on the version: the game runs exactly as on the hub (scores aren't saved) with an SDK log showing every message the game sends. The SDK integration check must show all 3 ✓ before review: the game calls GameHub.init(), calls gameStart() when a run starts, and calls gameOver(score) when it ends.

Game Hub SDK ​

Include the SDK ​

Functions ​

init data ​

Events ​

scoreResult data ​

Ads ​

Full example ​

Test before submitting for review ​