App — Heartbeat

The LiSA Player regularly sends a Heartbeat to signal its continued availability.

This message is sent by the LiSA Player to the host app / environment.

Properties

Along with all standard Message properties, a Heartbeat message includes the following additional properties:

Name	Type	Description
messageType	Literal Required.	lsc:app:heartbeat

Legacy Properties

If your integration uses LiSA Player Version 1, none of the properties described above will be available.

For LiSA Player Version 2, legacy properties can be ignored.

Name	Type	Description
action	Literal Required.	heartbeat ⚠️ Please use messageType instead.
playing	Boolean Required.	The playing property signifies whether media playback is currently in progress. ⚠️ Please subscribe to Media Progress message instead.
target	Literal Required.	player ⚠️ Please use messageType instead.
time	Number Optional.	The time property represents the current playback position of the media item, measured in milliseconds from the start. For on-demand content (e.g., replays, stories), this value indicates the exact position the user is watching. For live streams, this value represents the current timestamp relative to the live broadcast ⚠️ Please subscribe to Media Progress message instead.

---

Type Definition

interface AppHeartbeatMessage extends Omit<
  Message,
  'messageType' | 'sender'
> {
  messageType: 'lsc:app:heartbeat';
  sender: 'LiSA';
}

---

Examples

{
  "clockDriftInMs": 0,
  "messageType": "lsc:app:heartbeat",
  "sender": "LiSA",
  
  "action": "heartbeat",
  "playing": true,
  "target": "player",
  "time": 620
}