Build bite-sized games the whole jar can't put down.

Two ways into the jar

From zero to playable in 4 steps

1. 1

   Create your game folder

   Every game lives in its own folder. The folder name becomes the game id and its URL.

   folder structure

   public/
   └── games/
       └── my-game/          ←  the folder name IS your game id
           ├── index.html    ←  entry point (required)
           ├── game.js       ←  (optional) your code
           └── assets/       ←  (optional) images, audio, fonts
   
   # Live at:  games.thecookiejar.app/my-game

2. 2

   Add the CookieJar bridge

   Pause when the player swipes away, resume when they come back. Paste this once into your game.

   cookiejar-bridge.js

   // Pause when the player swipes away, resume on return.
   let paused = false;
   
   // From the native WebView shell (postMessage)
   window.addEventListener('message', (e) => {
     if (!e.data?.cookiejar) return;
     if (e.data.cookiejar === 'pause')  paused = true;   // game.pause()
     if (e.data.cookiejar === 'resume') paused = false;  // game.resume()
   });
   
   // From the in-browser inject (custom events)
   window.addEventListener('cookiejar:pause',  () => { paused = true; });
   window.addEventListener('cookiejar:resume', () => { paused = false; });

3. 3

   Report your score

   Call gameOver(score) the instant a run ends so it counts toward tournaments.

   report-score.js

   // Call ONCE per run, the moment the run ends (game over / out of lives).
   function reportScore(score) {
     score = Math.max(0, Math.floor(Number(score) || 0)); // clean integer
   
     if (window.CookieJar?.gameOver) {
       window.CookieJar.gameOver(score);        // preferred
     } else if (window.CookieJar?.submitScore) {
       window.CookieJar.submitScore(score);     // fallback
     }
     // No CookieJar object? You're running outside the app — that's fine,
     // your game still works standalone in the browser.
   }
   
   function endGame() {
     // ...show your game-over screen...
     reportScore(currentScore);
   }

4. 4

   Submit & publish

   Send us your game folder. Once it's in, it's instantly live at games.thecookiejar.app/your-game-id and starts surfacing in the feed. 🎉

The CookieJar bridge

The bridge is how your game and the app talk. It's two small contracts — and both are optional safety nets, so your game always works on its own too.

Make your game competitive

Tournaments turn any game into a leaderboard race. You don't build the leaderboard — CookieJar does. You just report an honest score and the platform handles ranking, timing, and prizes.

// Call ONCE per run, the moment the run ends (game over / out of lives).
function reportScore(score) {
  score = Math.max(0, Math.floor(Number(score) || 0)); // clean integer

  if (window.CookieJar?.gameOver) {
    window.CookieJar.gameOver(score);        // preferred
  } else if (window.CookieJar?.submitScore) {
    window.CookieJar.submitScore(score);     // fallback
  }
  // No CookieJar object? You're running outside the app — that's fine,
  // your game still works standalone in the browser.
}

function endGame() {
  // ...show your game-over screen...
  reportScore(currentScore);
}

⚠️ Fair play: send the score only when the run is genuinely over, never mid-run, and never more than once. Clamp negatives to zero and round to a whole number so every board stays clean.

Shipping a Godot game

Export your project to HTML5 (Project → Export → Web), then reach the bridge through JavaScriptBridge — Godot's window into the page's JavaScript.

# Godot 4 — call the JS bridge from GDScript after exporting to HTML5.
func _report_score(score: int) -> void:
    if OS.has_feature("web"):
        JavaScriptBridge.eval("""
            (function(s){
              if (window.CookieJar && window.CookieJar.gameOver)
                window.CookieJar.gameOver(Math.max(0, Math.floor(s)));
            })(%d);
        """ % score)

# Pause / resume — listen for CookieJar events and toggle the tree.
func _ready() -> void:
    if OS.has_feature("web"):
        var cb := JavaScriptBridge.create_callback(_on_cookiejar)
        JavaScriptBridge.eval("window.__cjPause = null;")
        # bind cb to window events in your HTML shell, then:
    pass

func _on_cookiejar(args) -> void:
    get_tree().paused = (args[0] == "pause")

Tip: wrap every bridge call in OS.has_feature("web") so your desktop test builds don't choke on the missing browser APIs.

What makes a great jar game