Clients

The SDK exports three clients. Each supports Mainnet and Testnet; public queries do not require a signer.

Client	Interface	Use
RestClient	HTTP requests	Query data or submit signed actions with await.
WebsocketClient	WebSocket subscriptions	Receive updates through event listeners.
WebsocketAPIClient	WebSocket requests	Call the REST client's methods over a persistent connection.

RestClient

RestClient sends HTTP requests and returns promises.

import { RestClient } from '@siebly/hyperliquid-api';

async function main() {
  const client = new RestClient();
  const mids = await client.getAllMids();
  if (mids.BTC === undefined) {
    throw new Error('BTC was not present in the mid-price response.');
  }
  console.log('BTC mid price:', mids.BTC);
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

Market data methods work without credentials. Account queries need an account address; signed actions need a private key or signer. See Authentication.

RestClient reference · Market data examples

WebsocketClient

Use WebsocketClient for subscriptions. Register message and exception listeners before calling subscribe(). The client opens the required connection automatically.

subscribe() resolves after sending locally. Server acknowledgements arrive on response. See the subscription example for event handling and cleanup.

Call unsubscribe() to remove a topic while keeping the connection, or closeAll() to close all connections. Removing an event listener does not remove the subscription.

WebsocketClient reference · Subscription types

WebsocketAPIClient

WebsocketAPIClient extends RestClient and sends the same methods through Hyperliquid's WebSocket POST protocol.

import { WebsocketAPIClient } from '@siebly/hyperliquid-api';

async function main() {
  const client = new WebsocketAPIClient();
  client.on('exception', (event) => console.error(event));

  try {
    const mids = await client.getAllMids();
    console.log(mids.BTC);
  } finally {
    client.close();
  }
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

The first request opens the connection. Close the client when finished. For streaming updates, use WebsocketClient subscriptions instead.

WebsocketAPIClient reference · Client configuration