state_subscribeStorage

Description

Subscribe to storage or runtime version updates over WebSocket. Drive live UIs that react to on‑chain changes.

Subscribes to storage changes for the provided keys. Requires WebSocket endpoint.

Code Examples

cURL

Not supported over HTTP; use WebSocket.

JavaScript (polkadot.js)

import { ApiPromise, WsProvider } from '@polkadot/api';

const api = await ApiPromise.create({ provider: new WsProvider('wss://api-bittensor-mainnet.n.dwellir.com/YOUR_API_KEY') });
const unsub = await api.rpc.state.subscribeStorage([[ '0x3a636f6465' ]], (changes) => {
console.log('storage changed:', changes.toHuman());
});

// Later: await unsub();