Saves

Sliver provides a small save system built on top of localStorage. It’s designed for quick, ergonomic “snapshot” saves:

• Save payloads are JSON-serialized and base64-encoded.
• Each save has an id, timestamps, and an optional label.
• The engine loads saves during Game.setup() (before onSetup()), so you can restore state early.

Accessing saves

Your Game instance exposes game.saves:

const saves = game.saves;

Optionally, give saves a namespace so multiple games don’t collide in localStorage:

const game = new Game({
  canvas,
  scenes,
  soundManager,
  saveNamespace: "my-game",
});

Save types

Index entry (metadata only)

list() returns SaveIndexEntry[]:

• id: string
• createdAt: number (ms timestamp)
• updatedAt: number (ms timestamp)
• label?: string

Full save file

read() / loadAll() return a SaveFile<T>:

type SaveFile<T> = {
  id: string;
  createdAt: number;
  updatedAt: number;
  label?: string;
  data: T;
};

Creating a save

Use create(data, options?):

type GameState = { level: number; hp: number };

const id = game.saves.create<GameState>(
  { level: 3, hp: 10 },
  { label: "Checkpoint" }
);

• If you don’t provide an id, Sliver generates one (crypto.randomUUID() when available).
• create always writes (it’s “create if missing” by default).

Updating an existing save

Use write(id, data, options?):

game.saves.write(id, { level: 4, hp: 7 }, { label: "After boss" });

If you want “write only if it already exists”, pass createIfMissing: false:

game.saves.write(id, state, { createIfMissing: false });

Listing saves (for a load menu)

const entries = game.saves.list();
// entries are sorted by updatedAt (most recent first)

Reading a save

const save = game.saves.read<GameState>(id);
if (!save) return;

console.log(save.label, save.data.level);

If the data is missing or can’t be decoded/parsed, read() returns null.

Loading saves on startup

The engine calls game.saves.loadAll() during game.setup(). To react to each loaded save, register a callback:

game.onLoadSaveFile((save) => {
  console.log("Loaded save:", save.id, save.label);
});

Notes:

• The callback runs once per save file during setup.
• loadAll() continues even if one save is corrupted; corrupted entries are skipped.

Deleting and clearing

Delete a single save by id:

game.saves.delete(id);

Clear all saves for the current namespace:

game.saves.clear();

Best practices

• Keep save payloads small: localStorage is limited and synchronous.
• Version your data: include a schemaVersion in your saved data, so you can migrate later.
• Treat read() as nullable: users can clear storage, or old saves might be invalid JSON.
• Use labels for UX: labels are stored in the index and are cheap to display in menus.