Connection Details

These apply to all WebSocket channels unless noted.

Keep-alive

Send a ping at least every 30 seconds to keep the connection open:

Request

{"action": "ping"}

Response

{"type": "pong"}

Only client messages reset the 30 second timeout; server messages and WebSocket protocol ping frames do not.

Limits

Limit	Value	When exceeded
Client silence	30 seconds	Disconnected with client_timeout.
Connection lifetime	24 hours	Disconnected with connection_lifetime.
Subscription requests	30 per minute per connection, subscribe and unsubscribe combined	Error message; the request is not applied. The connection stays open.
Size of a message you send	16 KiB	Disconnected without an error message.
User data connections	10 per account	Disconnected with Max connections per account exceeded.

Errors

Disconnecting

Reconnect and resubscribe.

Message	Cause
client_timeout	No client message for 30 seconds.
connection_lifetime	Connection reached 24 hours.
md_lagged	The client read messages too slowly.
feed_overflow	The client read messages too slowly.
internal_error	Server error on a subscribed market.
Max connections per account exceeded.	Already 10 user data connections.

Non-disconnecting

The request was not applied.

Message	Cause
Invalid message format: ...	Malformed JSON or unknown action.
Rate limit exceeded for subscribe requests. (or unsubscribe)	Over 30 subscription requests in a minute.
market_ids cannot be empty for Market Data channel.	Empty market_ids.
No valid markets provided.	No valid market IDs.
No subscribable markets provided.	Every requested market’s feed is temporarily unavailable.
Must subscribe to at least one type of status update.	User data subscribe with no valid markets and lsu false.
Must unsubscribe from at least one type of status update.	User data unsubscribe with no valid markets and lsu false.