(use-package :fast-websocket)

(let* ((ws (make-ws))
       (body (make-string-output-stream))
       (parser (make-parser ws
                            :require-masking t
                            :message-callback
                            (lambda (message)
                              (princ message body))
                            :close-callback
                            (lambda (payload &key code)
                              (format t "Client closed a connection: ~A (Code: ~D)~%" payload code)))))
  (funcall parser (make-array 11 :element-type '(unsigned-byte 8)
                              :initial-contents (list 129 133 225 106 10 29 169 15 102 113 142)))

  (princ (opcode-name (ws-opcode ws)))
  ;-> :TEXT

  (princ (get-output-stream-string body))
  ;-> Hello

  t)

(compose-frame "bye" :type :close :code (error-code :protocol-error))
;=> #(136 5 3 234 98 121 101)