diff --git a/google-gemini-content.el b/google-gemini-content.el
index 05ba2c1..dba6e50 100644
--- a/google-gemini-content.el
+++ b/google-gemini-content.el
@@ -42,7 +42,9 @@
                                            top-p
                                            top-k)
   "Send generate content request."
-  (google-gemini-request (format "https://generativelanguage.googleapis.com/v1beta/models/gemini-pro:generateContent?key=%s" key)
+  (google-gemini-request (concat google-gemini-generativelanguage-url
+                                 "v1beta/models/gemini-pro:generateContent?key="
+                                 key)
     :type "POST"
     :headers (google-gemini--headers content-type)
     :data (google-gemini--json-encode
@@ -65,16 +67,16 @@
 
 ;;;###autoload
 (defun google-gemini-content-prompt ()
-  "Start making a conversation to Google Gemini."
+  "Ask to generate contents from Google Gemini."
   (interactive)
-  (if-let ((text (read-string "Content: ")))
+  (if-let ((text (read-string "[Generate] Content: ")))
       (google-gemini-content-generate text
                                       (lambda (data)
                                         (let-alist data
                                           (let-alist (elt .candidates 0)
                                             (let-alist .content
                                               (let-alist (elt .parts 0)
-                                                (message "%s" .text)))))))
+                                                (message "Response: %s" .text)))))))
     (user-error "Abort, cancel generate content operation")))
 
 (provide 'google-gemini-content)
diff --git a/google-gemini-count-tokens.el b/google-gemini-count-tokens.el
new file mode 100644
index 0000000..6e93155
--- /dev/null
+++ b/google-gemini-count-tokens.el
@@ -0,0 +1,63 @@
+;;; google-gemini-count-tokens.el --- Create count tokens request with Google Gemini API  -*- lexical-binding: t; -*-
+
+;; This file is not part of GNU Emacs.
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Create count tokens request with Google Gemini API.
+;;
+
+;;; Code:
+
+(require 'google-gemini)
+
+;;
+;;; API
+
+;;;###autoload
+(cl-defun google-gemini-count-tokens ( text callback
+                                       &key
+                                       (content-type "application/json")
+                                       (key google-gemini-key))
+  "Send count tokens request."
+  (google-gemini-request (concat google-gemini-generativelanguage-url
+                                 "v1beta/models/gemini-pro:countTokens?key="
+                                 key)
+    :type "POST"
+    :headers (google-gemini--headers content-type)
+    :data (google-gemini--json-encode
+           `(("contents" . [((parts . [((text . ,text))]))])))
+    :parser 'json-read
+    :complete (cl-function
+               (lambda (&key data &allow-other-keys)
+                 (funcall callback data)))))
+
+;;
+;;; Application
+
+;;;###autoload
+(defun google-gemini-count-tokens-prompt ()
+  "Send request to count tokens."
+  (interactive)
+  (if-let ((text (read-string "[Count Tokens] Content: ")))
+      (google-gemini-count-tokens text
+                                  (lambda (data)
+                                    (let-alist data
+                                      (message "`totalTokens` is %s" .totalTokens))))
+    (user-error "Abort, cancel generate content operation")))
+
+(provide 'google-gemini-count-tokens)
+;;; google-gemini-count-tokens.el ends here
diff --git a/google-gemini.el b/google-gemini.el
index 98fc91b..7c22ab4 100644
--- a/google-gemini.el
+++ b/google-gemini.el
@@ -140,5 +140,12 @@ The URL is the url for `request' function; then BODY is the arguments for rest."
                  (google-gemini--handle-error response)))
        ,@body)))
 
+;;
+;;; Constants
+
+(defconst google-gemini-generativelanguage-url
+  "https://generativelanguage.googleapis.com/"
+  "Base Url for generativelanguage services.")
+
 (provide 'google-gemini)
 ;;; google-gemini.el ends here