mongoose/docs/c-api/mg_http.h/mg_send_websocket_framev.md

title	decl_name	symbol_kind	signature
mg_send_websocket_framev()	mg_send_websocket_framev	func	void mg_send_websocket_framev(struct mg_connection *nc, int op_and_flags, const struct mg_str *strings, int num_strings);

Like mg_send_websocket_frame(), but composes a single frame from multiple buffers.