WebSocket Overview

This page covers how to connect to the Limitless WebSocket API, how to sign the handshake for authenticated channels, and the full list of client and server events. Each subscription has its own page pairing the subscribe call with the payloads it delivers.

Connection

URL: wss://ws.limitless.exchange Namespace: /markets Transport: WebSocket only (no polling fallback)

No client PING required. The server runs the Socket.IO heartbeat (server-initiated ping / client pong) automatically. Every official Socket.IO client (JavaScript, Python python-socketio, Go, Rust) responds to it out of the box. Do not send your own PING frames. Keep the connection open and rely on the built-in heartbeat and the auto-reconnect flow in WebSocket quick start.

Authenticated channels (positions, order events) require an HMAC-signed handshake. Sign a fixed canonical message — {ISO-8601 timestamp}\nGET\n/socket.io/?EIO=4&transport=websocket\n — with the base64-decoded secret and pass three headers as extraHeaders:

import { createHmac } from 'crypto';
import { io } from 'socket.io-client';

function wsAuthHeaders(tokenId: string, secret: string) {
  const timestamp = new Date().toISOString();
  const message = `${timestamp}\nGET\n/socket.io/?EIO=4&transport=websocket\n`;
  const signature = createHmac('sha256', Buffer.from(secret, 'base64'))
    .update(message)
    .digest('base64');
  return { 'lmts-api-key': tokenId, 'lmts-timestamp': timestamp, 'lmts-signature': signature };
}

const socket = io('wss://ws.limitless.exchange/markets', {
  transports: ['websocket'],
  extraHeaders: wsAuthHeaders(TOKEN_ID, SECRET),
});

See Authentication for how to generate TOKEN_ID and SECRET. If you use an official SDK, prefer its WebSocket client, which signs the handshake automatically from hmacCredentials (TypeScript) / hmac_credentials (Python) / WithHMACCredentials (Go).

Event reference

Event	Direction	Auth required	Description
`connect`	Server → Client	No	Connection established
`disconnect`	Server → Client	No	Connection lost
`subscribe_market_prices`	Client → Server	No	Subscribe to price/orderbook updates
`subscribe_positions`	Client → Server	Yes	Subscribe to position updates
`subscribe_order_events`	Client → Server	Yes	Subscribe to OME and settlement events for your CLOB orders
`subscribe_market_lifecycle`	Client → Server	No	Subscribe to market creation/resolution events
`unsubscribe_market_lifecycle`	Client → Server	No	Unsubscribe from market lifecycle events
`subscribe_unrealized_pnl`	Client → Server	No	Subscribe to Unrealized PnL leaderboard invalidation hints
`unsubscribe_unrealized_pnl`	Client → Server	No	Unsubscribe from Unrealized PnL invalidation hints
`unrealizedPnlProjectionChanged`	Server → Client	No	Hint that a subscribed Unrealized PnL leaderboard changed; refetch the REST route
`newPriceData`	Server → Client	No	AMM market price update
`orderbookUpdate`	Server → Client	No	CLOB orderbook update
`marketCreated`	Server → Client	No	New market created and visible
`marketResolved`	Server → Client	No	Market resolved with winning outcome
`positions`	Server → Client	Yes	Position balance update
`orderEvent`	Server → Client	Yes	OME lifecycle, FAK/FOK execution, and settlement updates for your CLOB orders
`system`	Server → Client	No	System notifications
`authenticated`	Server → Client	Yes	Authentication confirmation
`exception`	Server → Client	No	Error notifications

Unsubscribing

There is no generic unsubscribe event. Only two channels have an explicit unsubscribe: unsubscribe_market_lifecycle and unsubscribe_unrealized_pnl. subscribe_market_prices, subscribe_positions, and subscribe_order_events have none. Each of those replaces its previous subscription on the same connection when you emit it again, so to drop a market you re-emit the subscribe with the smaller set. To stop everything, disconnect. An unsubscribe event name that the server does not register never gets an acknowledgement, so a client waiting on one times out. Each subscription has its own page pairing the subscribe call with the payloads it delivers:

Market data: subscribe_market_prices, newPriceData, orderbookUpdate
Positions: subscribe_positions, positions
Order events: subscribe_order_events, orderEvent
Market lifecycle: subscribe_market_lifecycle, unsubscribe_market_lifecycle, marketCreated, marketResolved
Unrealized PnL: subscribe_unrealized_pnl, unsubscribe_unrealized_pnl, unrealizedPnlProjectionChanged

Getting Started

Quick Start

TypeScript SDK

Python SDK

Go SDK

Rust SDK

WebSocket

Connection

Event reference

Unsubscribing

​Connection

​Event reference

​Unsubscribing

​Related

Connection

Event reference

Unsubscribing

Related