diff --git a/js/admin.js b/js/admin.js
index dc61880..fe12a21 100644
--- a/js/admin.js
+++ b/js/admin.js
@@ -251,8 +251,8 @@ export const admin = (() => {
         comment.init();
 
         try {
-            // window.atob can throw error
-            if (!session.isAdmin() || !session.getToken() || (JSON.parse(window.atob(session.getToken().split('.')[1]))?.exp ?? 0) < (Date.now() / 1000)) {
+            const jwt = session.decode();
+            if (!jwt || (jwt.exp ?? 0) < (Date.now() / 1000)) {
                 throw new Error('invalid token');
             }
 
diff --git a/js/guest.js b/js/guest.js
index 45c9ef9..c8ce2f1 100644
--- a/js/guest.js
+++ b/js/guest.js
@@ -145,18 +145,23 @@ export const guest = (() => {
             return;
         }
 
-        comment.init();
         progress.add();
+        progress.add();
+        comment.init();
+
         session.guest()
             .then((res) => {
                 if (res.code !== 200) {
+                    progress.invalid('request');
                     return res;
                 }
 
-                return comment.comment()
+                progress.complete('request');
+                comment.comment()
                     .then(() => progress.complete('comment'))
                     .catch(() => progress.invalid('comment'));
-            });
+            })
+            .catch(() => progress.invalid('request'));
     };
 
     return {
diff --git a/js/request.js b/js/request.js
index 49e9e22..69de110 100644
--- a/js/request.js
+++ b/js/request.js
@@ -11,15 +11,17 @@ export const HTTP_DELETE = 'DELETE';
 export const request = (method, path) => {
 
     const controller = new AbortController();
+    const header = new Headers({
+        'Accept': 'application/json',
+        'Content-Type': 'application/json'
+    });
+
     offline.addAbort(() => controller.abort());
 
     let url = document.body.getAttribute('data-url');
     let req = {
         method: String(method).toUpperCase(),
-        headers: new Headers({
-            'Accept': 'application/json',
-            'Content-Type': 'application/json'
-        }),
+        headers: header,
         signal: controller.signal,
     };
 
@@ -60,6 +62,9 @@ export const request = (method, path) => {
                     throw new Error(err);
                 });
         },
+        /**
+         * @returns {Promise<boolean>}
+         */
         download() {
             return fetch(url + path, req)
                 .then((res) => {
@@ -101,6 +106,10 @@ export const request = (method, path) => {
                     throw new Error(err);
                 });
         },
+        /**
+         * @param {string} token
+         * @returns {this}
+         */
         token(token) {
             if (session.isAdmin()) {
                 req.headers.append('Authorization', 'Bearer ' + token);
@@ -110,6 +119,10 @@ export const request = (method, path) => {
             req.headers.append('x-access-key', token);
             return this;
         },
+        /**
+         * @param {object} body
+         * @returns {this}
+         */
         body(body) {
             req.body = JSON.stringify(body);
             return this;
diff --git a/js/session.js b/js/session.js
index ca120bc..affcb50 100644
--- a/js/session.js
+++ b/js/session.js
@@ -1,59 +1,98 @@
 import { dto } from './dto.js';
 import { storage } from './storage.js';
-import { progress } from './progress.js';
 import { request, HTTP_POST, HTTP_GET } from './request.js';
 
 export const session = (() => {
 
-    let session = null;
+    /**
+     * @type {ReturnType<typeof storage>}
+     */
+    let ses = null;
 
-    const getToken = () => session.get('token');
+    /**
+     * @returns {string}
+     */
+    const getToken = () => ses.get('token');
 
+    /**
+     * @param {object} body
+     * @returns {Promise<boolean>}
+     */
     const login = (body) => {
         return request(HTTP_POST, '/api/session')
             .body(body)
             .send(dto.tokenResponse)
-            .then((res) => {
-                if (res.code === 200) {
-                    session.set('token', res.data.token);
-                }
+            .then(
+                (res) => {
+                    if (res.code === 200) {
+                        setToken(res.data.token);
+                    }
 
-                return res;
-            })
-            .then((res) => res.code === 200, () => false);
+                    return res.code === 200;
+                },
+                () => false
+            );
     };
 
-    const logout = () => session.unset('token');
+    /**
+     * @returns {void}
+     */
+    const logout = () => ses.unset('token');
 
-    const isAdmin = () => String(getToken() ?? '.').split('.').length === 3;
+    /**
+     * @param {string} token
+     * @returns {void}
+     */
+    const setToken = (token) => ses.set('token', token);
 
+    /**
+     * @returns {boolean}
+     */
+    const isAdmin = () => getToken().split('.').length === 3;
+
+    /**
+     * @returns {Promise<ReturnType<typeof dto.baseResponse<object>>}
+     */
     const guest = () => {
-        progress.add();
+        const config = storage('config');
+
         return request(HTTP_GET, '/api/config')
             .token(document.body.getAttribute('data-key'))
             .send()
             .then((res) => {
                 if (res.code !== 200) {
-                    progress.invalid('request');
                     return res;
                 }
 
-                const config = storage('config');
                 for (let [key, value] of Object.entries(res.data)) {
                     config.set(key, value);
                 }
 
-                session.set('token', document.body.getAttribute('data-key'));
-                progress.complete('request');
-
+                setToken(document.body.getAttribute('data-key'));
                 return res;
-            }).catch(() => {
-                progress.invalid('request');
             });
     };
 
+    /**
+     * @returns {object|null}
+     */
+    const decode = () => {
+        if (!isAdmin()) {
+            return null;
+        }
+
+        try {
+            return JSON.parse(window.atob(getToken().split('.')[1]));
+        } catch {
+            return null;
+        }
+    };
+
+    /**
+     * @returns {void}
+     */
     const init = () => {
-        session = storage('session');
+        ses = storage('session');
     };
 
     return {
@@ -61,7 +100,9 @@ export const session = (() => {
         guest,
         login,
         logout,
+        decode,
         isAdmin,
+        setToken,
         getToken,
     };
 })();
\ No newline at end of file
diff --git a/js/storage.js b/js/storage.js
index 553ca70..815059c 100644
--- a/js/storage.js
+++ b/js/storage.js
@@ -1,39 +1,59 @@
 export const storage = (table) => {
 
+    /**
+     * @param {string=} key
+     * @returns {any}
+     */
     const get = (key = null) => {
         const data = JSON.parse(localStorage.getItem(table));
         return key ? data[String(key)] : data;
     };
 
+    /**
+     * @param {string} key
+     * @param {any} value
+     * @returns {void}
+     */
     const set = (key, value) => {
-        let storage = get();
-        storage[String(key)] = value;
-        localStorage.setItem(table, JSON.stringify(storage));
+        let data = get();
+        data[String(key)] = value;
+        localStorage.setItem(table, JSON.stringify(data));
     };
 
+    /**
+     * @param {string} key
+     * @returns {boolean}
+     */
     const has = (key) => Object.keys(get()).includes(String(key));
 
+    /**
+     * @param {string} key
+     * @returns {void}
+     */
     const unset = (key) => {
         if (!has(key)) {
             return;
         }
 
-        let storage = get();
-        delete storage[String(key)];
-        localStorage.setItem(table, JSON.stringify(storage));
+        let data = get();
+        delete data[String(key)];
+        localStorage.setItem(table, JSON.stringify(data));
     };
 
-    const clear = () => localStorage.setItem(table, JSON.stringify({}));
+    /**
+     * @returns {void}
+     */
+    const clear = () => localStorage.setItem(table, '{}');
 
     if (!localStorage.getItem(table)) {
         clear();
     }
 
     return {
-        get,
         set,
-        unset,
+        get,
         has,
         clear,
+        unset,
     };
 };
\ No newline at end of file