websocat
Command-line client for WebSockets, like netcat (or curl)
...Command-line client for WebSockets, like netcat (or curl) for ws:// with advanced socat-like functions. Connecting to and serving WebSockets from the command line. Executing external program and making it communicate to WebSocket using stdin/stdout. Text and binary modes, converting between lines (or null-terminated records) and messages. Inetd mode, UNIX sockets (including abstract namespaced on Linux). Integration with Nginx using TCP or UNIX sockets. Directly using unauthenticated SOCKS5 servers for connecting to WebSockets and listening WebSocket connections. ...