App-only & offline

The single most important thing to understand about the SDK:

Coins only work inside the Gamma Games app. That's where the host injects the real, server-authoritative bridge. Outside the app — your own website, another portal, a plain dev browser — the SDK is inert by default.

What "inert" means

When the game runs outside the Gamma Games app and the dev mock is not enabled:

Call	Result outside the app
getCoins()	0
spendCoins(...)	{ok: false, error: 'no_transport'}
earnCoins(...)	{ok: false, error: 'no_transport'}
getCoinValue()	default value (display constant)
getPlayer()	null
gamma.storage.*	works — falls back to localStorage

Nothing can fake or spend real coins outside the app, by design.

Always gate on isInApp

After gamma.ready(), check gamma.isInApp:

await gamma.ready();

if (gamma.isInApp) {
  const res = await gamma.spendCoins(50, 'extra_life');
  if (res.ok) grantExtraLife();
} else {
  // Running outside Gamma Games — use your own offline behaviour
  // (e.g. let the player continue for free, or hide the coin shop).
}

gamma.storage keeps working everywhere, so progress/saves are unaffected — only the coin economy is app-gated.

Why it's built this way

• The coin balance lives on the server; the game can only ask to spend, and the server validates against the authenticated user.
• The host supplies the user identity — the game never sends it and can't spoof it.
• Outside the app there's no authenticated session, so there's nothing to spend.

See Limits & security for the full model.