libjapi is a universal JSON to C API library. It receives newline-delimited JSON (NDJSON) messages via TCP and calls registered C functions. A JSON response is returned for each request. Furthermore, it is also possible to create push services, which asynchronously push JSON messages to the clients subscribed to them.
In GitLab by @cstender on Jul 26, 2019, 12:07
Websocket support shall be implemented directly into libjapi.
List of existing libraries:
https://en.wikipedia.org/wiki/Comparison_of_WebSocket_implementations