gist.el

    (puthash filename file files)
    (puthash "files" files payload)
    (let ((url-request-method "POST")
          (url-request-extra-headers `(("Content-Type" . "application/json") ("User-Agent" . "gist.el") ("Authorization" . ,(concat "Bearer " oauth-token))))
          (url-request-data (json-encode payload)))
      (url-retrieve "https://api.github.com/gists" 'my/gist-handle-response))))

(defun my/gist-handle-response ()
  "Process content of RESPONSE and extract link."
  (interactive)