Save data

The data module persists player data across sessions and devices. For signed-in users, data syncs through Funox; for guests, it's stored in localStorage and migrated on sign-in.

Limits​

• Maximum 1 MB of total stored data per game per player.
• Saves are debounced ~1 second — frequent setItem calls batch into one write.
• In high-volume periods, the debounce can stretch up to 30 seconds.
• Exceeding the size limit returns the dataLimitExceeded error.

setItem(key, value)​

Store a string value under a key.

1window.Funox.SDK.data.setItem("highScore", "12450");2window.Funox.SDK.data.setItem("inventory", JSON.stringify(items));

Use JSON.stringify for objects, arrays, numbers, and booleans.

getItem(key)​

Retrieve a value by key. Returns null if the key doesn't exist.

1const score = window.Funox.SDK.data.getItem("highScore");2const items = JSON.parse(window.Funox.SDK.data.getItem("inventory") ?? "[]");

removeItem(key)​

Delete a single key.

1window.Funox.SDK.data.removeItem("inventory");

clear()​

Delete all stored data for the current player in your game. Use cautiously.

1window.Funox.SDK.data.clear();

Guest vs. signed-in​

When a guest signs in, all guest data automatically migrates to their account. No code needed.

Don't sync this key​

Prefix keys you don't want to sync (debug flags, device-specific settings) with funox_ignore_:

1window.Funox.SDK.data.setItem("funox_ignore_lastDevice", "iPhone");

Funox-ignored keys stay in localStorage only.

Best practices​

• Save on meaningful state changes, not every frame.
• Read once at game boot — cache the values in memory.
• Version your save format ({ version: 2, ... }) so you can migrate later.
• Don't store anything sensitive — clients can read their own save data.

1function loadSave() {2  const raw = window.Funox.SDK.data.getItem("save");3  if (!raw) return defaultState();4 5  const save = JSON.parse(raw);6  if (save.version === 1) return migrateV1(save);7  return save;8}9 10function persistSave(state) {11  window.Funox.SDK.data.setItem("save", JSON.stringify({12    version: 2,13    ...state,14  }));15}

Engine-specific helpers​

Some engines provide typed wrappers:

See your engine guide for details.