Skip to main content

​
Lark SDK

The Lark SDK (@lark-sh/client) is the official JavaScript/TypeScript client for Lark databases. It gives you real-time data synchronization, offline support, and a modern developer experience in a lightweight package.

​
Why the Lark SDK?

Small footprint. The entire SDK is ~20KB gzipped. No bloated dependency trees. It loads fast and stays out of your way. Modern API design. Subscriptions return an unsubscribe function directly — no need to track callbacks or call a separate off() method. This plays nicely with React’s useEffect cleanup, Vue’s onUnmounted, and any other framework lifecycle pattern. 
import { LarkDatabase } from "@lark-sh/client";

const db = new LarkDatabase("my-project/my-database");

// on() returns an unsubscribe function
const unsubscribe = db.ref("scores").on("value", (snapshot) => {
  console.log(snapshot.val());
});

// Clean up when you're done
unsubscribe();
First-class WebTransport support. The SDK automatically negotiates the best transport available. When WebTransport (HTTP/3) is supported, you get lower latency and better multiplexing. It falls back to WebSocket seamlessly. Volatile path support. Ephemeral data like cursor positions, typing indicators, and player coordinates can flow through volatile paths — high-frequency updates that skip persistence for maximum speed. Full TypeScript types. Every method, option, and return value is fully typed. You get autocompletion and compile-time safety without installing separate type packages.

​
Installation

npm install @lark-sh/client
Or with your preferred package manager: 
yarn add @lark-sh/client
pnpm add @lark-sh/client

​
Platform support

The Lark SDK works in browsers and Node.js. Both CommonJS and ESM builds are included — your bundler or runtime will pick the right one automatically.
PlatformSupport
Modern browsers (Chrome, Firefox, Safari, Edge)Full support
Node.js 18+Full support
React NativeFull support
DenoESM import

​
Package

Everything you need is in a single package: 
import { LarkDatabase, ServerValue } from "@lark-sh/client";
If you’re migrating from Firebase v8, the SDK also ships a compatibility layer at @lark-sh/client/fb-v8. See the Firebase v8 compatibility page for details.

​
What’s next

Quickstart

Connect, write, read, and subscribe in under five minutes.

Connecting

Connection options, transports, and lifecycle events.

Writing data

Set, update, remove, push, and multi-path writes.

Subscriptions

Listen for real-time changes with different event types.