Developer DocsBuild & publish your own casino games

Provably Fair

Build casino games with a single HTML file.

You handle UI and game design. GeeWin handles randomness, balances, payouts, and provably fair verification.

How It Works

Your game runs inside a sandboxed iframe on the GeeWin platform. All communication happens via the browser's postMessage API — your game sends bet/action messages to the platform, and the platform responds with results.

Quick Start

Every game is an HTML file with two things: a config and postMessage communication.

1<script>
2  // 1. Declare your game config
3  window.GAME_CONFIG = {
4    primitive: 'one-shot',
5    multipliers: [0, 0.5, 1, 2, 5, 10, 50]
6  };
7
8  // 2. Place a bet
9  function bet() {
10    parent.postMessage({
11      type: 'bet',
12      id: Date.now(),
13      stake: window.GAME_STAKE,
14      currency: window.GAME_CURRENCY
15    }, '*');
16  }
17
18  // 3. Get the result (matched by id)
19  window.addEventListener('message', (e) => {
20    if (e.data.type === 'betResult' && e.data.id) {
21      const { multiplier, payout, result } = e.data.result;
22      // result = 'WIN' | 'LOSS' | 'PUSH'
23      // Animate your game with the result
24    }
25  });
26
27  // 4. Tell the platform you're ready (required!)
28  parent.postMessage({ type: 'gameReady' }, '*');
29</script>

Choose a Primitive

Each primitive handles a different type of game. Pick the one that fits your game design.

Quick Reference

Platform Variables

The platform injects these into your game's window before it loads: