Subscribe to live quotes, news, SEC filings, and trading halts over one authenticated socket. Sub-second market events, without polling REST.
Authenticate once when the socket opens, then subscribe to any combination of channels for the tickers you care about. Unsubscribing and resubscribing doesn't require a new connection.
Included on Ultimate - built for real-time dashboards, monitors, and event-driven workflows that can't afford to poll.
The WebSocket API is exclusive to Ultimate ($50/mo, or $40/mo billed annually). It isn't included on Pro.
Only if polling isn't fast enough. Most dashboards and bots do fine on a REST polling schedule - reach for WebSocket when you need sub-second, push-based updates instead.
Yes - authenticate once, then subscribe to any combination of quotes, news, filings, and halt channels for the tickers you're watching, all over one socket.
LS streams tick-level quote updates as trades happen. LM aggregates into minute bars, so you get OHLCV candles without recomputing them client-side.
Open the connection with your Ultimate API key, then subscribe to channels. Auth, reconnect, and heartbeat details are in the WebSocket docs.
Reconnect and resubscribe to the same channels. The socket does not replay missed ticks; use REST for historical bars if you need to fill a gap after a disconnect.
Yes - connection, auth, and every channel's message shape are covered in the docs, alongside the REST API and MCP server reference.
Free to start. $20 or $40 a month unlocks live data, AI chat, and full API access.