libwslay-dev binary package in Ubuntu Mantic amd64

 WebSocket library written in C. It implements the protocol version 13
 described in RFC 6455. This library offers 2 levels of API: event-based
 API and frame-based low-level API. For event-based API, it is suitable
 for non-blocking reactor pattern style. You can set callbacks in various
 events. For frame-based API, you can send WebSocket frame directly.
 Wslay only supports data transfer part of WebSocket protocol and does not
 perform opening handshake in HTTP.
 .
 Wslay supports:
 .
  - Text/Binary messages.
  - Automatic ping reply.
  - Callback interface.
  - External event loop.
  - Wslay does not perform any I/O operations for its own. Instead, it
    offers callbacks for them. This makes Wslay independent on any I/O
    frameworks, SSL, sockets, etc. This makes Wslay portable across various
    platforms and the application authors can choose freely I/O frameworks.
 .
 The binary contains development files.

Source package