Storage Service

#8.12 StorageService — Scoped key-value persistence

Runs in: both worker and view. Writes from the worker are the source of truth for state that needs to survive view eviction.

Permission required: storage:read for reads, storage:write for writes.

The recommended way to persist extension data across sessions. Each extension gets its own isolated namespace backed by SQLite on the Rust side — extensions cannot read or write other extensions' data.

interface IStorageService {
  get(key: string): Promise<string | null>;
  set(key: string, value: string): Promise<void>;
  delete(key: string): Promise<boolean>;
  getAll(): Promise<Record<string, string>>;
  clear(): Promise<number>;
}

Usage:

const storage = context.getService<IStorageService>('storage');

// Store a value (values are strings — JSON.stringify complex data)
await storage.set('theme', 'dark');
await storage.set('bookmarks', JSON.stringify(['https://example.com']));

// Read a value
const theme = await storage.get('theme'); // "dark"
const raw = await storage.get('bookmarks');
const bookmarks = raw ? JSON.parse(raw) : [];

// Check if a key exists
const val = await storage.get('nonexistent'); // null

// Delete a single key
const wasDeleted = await storage.delete('theme'); // true

// Get everything
const all = await storage.getAll(); // { "bookmarks": "[\"https://example.com\"]" }

// Nuclear option — delete all your extension's data
const count = await storage.clear(); // number of deleted entries

How it works under the hood:

All extensions share one extension_storage table in asyar_data.db (SQLite, WAL mode). The IPC Router automatically injects your extensionId into every call — you never see it, and you cannot impersonate another extension. On uninstall, Asyar deletes all rows for your extension automatically.

When to use what:

Pro Tip: Values are plain strings. For objects and arrays, use JSON.stringify/JSON.parse. Keep keys short and descriptive — there's no size limit, but the entire table is shared across all extensions.