Show HN: Vaultrice – A real-time key-value store with a localStorage API

I'm Adriano, one of the makers of Vaultrice. I'm excited (and a little nervous!) to share what we've been building.

For years, we found ourselves in a frustrating loop: whenever we needed a simple real-time feature—like a "who's online" list, a collaborative app, or just sharing state between a marketing site and our main app — we'd end up spending days setting up the same stack or discarded to do it. Setting it up, it always involved wiring together a database, a WebSocket server, an API, and managing the connection state. It felt like massive overkill for what we were trying to achieve.

We wanted a tool that felt as simple to use as the browser's `localStorage` API but worked across domains and devices, with real-time sync and security built-in.

So, we built Vaultrice.

It’s a key-value data store built on top of Cloudflare's Durable Objects, which gives you a strongly consistent backend for each data object. You interact with it through our TS/JS SDK, which comes in two flavors:

1. `NonLocalStorage`: A low-level client with a `localStorage`-like API (`setItem`, `getItem`, etc.) plus real-time events and presence (`.on()`, `.join()`).

2. `SyncObject`: A higher-level, reactive JavaScript Proxy. You just change a property on an object (`doc.title = 'New Title'`), and it automatically syncs to all other connected clients.

The goal is to let you build the real-time features you want in minutes, not days. We've also put a lot of thought into a layered security model, allowing you to go from simple API key restrictions all the way to server-signed object IDs and client-side E2EE.

We’ve just launched and would be grateful for any feedback from the HN community. What do you think of the API design? Are there use cases we haven't considered? Any thoughts on the security model?

We'll be here (or via email (support@vaultrice.com)) to answer any questions. Thanks for checking it out!