Constant DERIBIT_WS_HEARTBEAT_SECS 

pub const DERIBIT_WS_HEARTBEAT_SECS: u64 = 30;

Default WebSocket heartbeat interval in seconds.

Deribit recommends heartbeats every 30-60 seconds. More frequent heartbeats may trigger stricter rate limits.

References

https://support.deribit.com/hc/en-us/articles/25944603459613