POS Ventas stores all of your data in the browser’s built-in localStorage. There is no server, no cloud account, and no internet connection required. Everything stays on your device, in your browser.
localStorage keys
The app uses five keys to persist data between sessions:
| Key | Contents |
|---|
pos_inventario | Product catalog — array of product objects |
pos_clientes | Client list — array of client objects with debt notes |
pos_ventas | Sales history — array of sale objects |
pos_version | App version string ("1.0.0") used for future data migrations |
pos_theme | Saved theme preference ("light" or "dark") |
First run
On the very first launch, if no products are found in pos_inventario, the app automatically loads 10 sample products so you have something to work with right away. You can edit or delete these samples and replace them with your real inventory.
Storage limits
Browsers limit localStorage to roughly 5 MB per origin. For a typical small shop — thousands of products, clients, and sales — this is more than enough. If you reach the limit, the app will log an error to the browser console when trying to write new data. Exporting and archiving old sales records can free up space if needed.
Data schema
The three main data types have the following shapes:
Product
{
"id": "lc4k2m9rx",
"codigo": "7501234567890",
"nombre": "Coca Cola 1L",
"precio": 5.50
}
{
"id": "lc4k2m9ry",
"nombre": "María García",
"telefono": "987654321",
"saldoDeuda": 12.50,
"notas": [
{
"id": "lc4k2m9rz",
"fecha": "2024-01-15T10:30:00.000Z",
"productos": [...],
"total": 12.50,
"pagado": 0,
"pendiente": 12.50
}
]
}
{
"id": "lc4k2m9s0",
"fecha": "2024-01-15T10:30:00.000Z",
"productos": [
{ "id": "p1", "nombre": "Coca Cola 1L", "precio": 5.50, "cantidad": 2 }
],
"total": 11.00,
"tipo": "efectivo",
"clienteId": null
}
ID generation
All records get a unique ID from the generateId() function:
generateId() {
return Date.now().toString(36) + Math.random().toString(36).substr(2);
}
lc4k2m9rx without requiring a server or UUID library.
Important limitations
Data is browser-specific. If you open the app in a different browser or on a different device, you will see empty data. localStorage is not shared between browsers or devices. Use export/import to move data between devices. Clearing browser data deletes everything. Clearing your browser’s cache, cookies, or site data will permanently erase all POS Ventas records — products, clients, and sales history. Export a backup regularly so you always have a copy you can restore.