> For the complete documentation index, see [llms.txt](https://engine.place.technology/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://engine.place.technology/api/control/websocket/heartbeat.md).

# Heartbeat

The client can periodically send a raw string as an application layer keep-alive.

`ping`

the server will respond

`pong`