diff --git a/Dockerfile b/Dockerfile
deleted file mode 100644
index f5b03017f..000000000
--- a/Dockerfile
+++ /dev/null
@@ -1,5 +0,0 @@
-FROM mhart/alpine-node:slim-10
-WORKDIR /app
-COPY .build /app
-EXPOSE 8888
-CMD ["node", ".build/app.js"]
diff --git a/README.md b/README.md
index 45a4c21e8..44c18bf2d 100644
--- a/README.md
+++ b/README.md
@@ -5,13 +5,11 @@ Hydro是一个高效的信息学在线测评系统。
 
 [中文文档](docs/deploy.md)
 
-Hydro 的界面基于 Vijos 二次开发。
-
 如果您认为本项目有价值，欢迎 star 。  
 
 ## 联系我们
 
-QQ [3402182471](tencent://AddContact/?uin=3402182471&subcmd=all)  
+QQ [3402182471](https://wpa.qq.com/msgrd?v=3&uin=3402182471&site=qq&menu=yes)  
 Telegram [@webpack_exports_undefined](https://t.me/webpack_exports_undefined)  
 
 ## 鸣谢
diff --git a/TODO b/TODO
index cfcc7f00c..e0222bba6 100644
--- a/TODO
+++ b/TODO
@@ -10,4 +10,3 @@ model.setting.ui.name
 pdoc.secretConfig?
 在线IDE 更换颜色主题, fix resize
 move to @hydrooj/core?
-remove koa-router
diff --git a/bin/hydrooj.js b/bin/hydrooj.js
index a04c41e35..cbeedc86b 100644
--- a/bin/hydrooj.js
+++ b/bin/hydrooj.js
@@ -1,20 +1,45 @@
 #!/usr/bin/env node
 
+const os = require('os');
+const path = require('path');
+const fs = require('fs-extra');
 const { argv } = require('yargs');
 const hydro = require('../dist/loader');
 
-const ui = argv.ui || '@hydrooj/ui-default';
+fs.ensureDirSync(path.resolve(os.homedir(), '.hydro'));
+const addonPath = path.resolve(os.homedir(), '.hydro', 'addon.json');
+if (!fs.existsSync(addonPath)) fs.writeFileSync(addonPath, '[]');
+const addons = JSON.parse(fs.readFileSync(addonPath).toString());
 
 try {
+    const ui = argv.ui || '@hydrooj/ui-default';
     require.resolve(ui);
+    addons.push(ui);
 } catch (e) {
     console.error('Please also install @hydrooj/ui-default');
-    process.exit(1);
 }
 
-hydro.addon(ui);
-
-hydro.load().catch((e) => {
-    console.error(e);
-    process.exit(1);
-});
+if (argv._[0]) {
+    const operation = argv._[0];
+    const arg1 = argv._[1];
+    const arg2 = argv._[2];
+    if (operation === 'addon') {
+        if (arg1 === 'add') addons.push(arg2);
+        else if (arg1 === 'remove') {
+            for (let i = 0; i < addons.length; i++) {
+                if (addons[i] === arg2) {
+                    addons.splice(i, 1);
+                    break;
+                }
+            }
+        }
+        console.log('Current Addons: ', addons);
+        fs.writeFileSync(addonPath, JSON.stringify(addons, null, 2));
+    }
+} else {
+    for (const addon of addons) hydro.addon(addon);
+    hydro.load().catch((e) => {
+        console.error(e);
+        process.exit(1);
+    });
+}
diff --git a/docker-compose.yml b/docker-compose.yml
deleted file mode 100644
index 89a4578f6..000000000
--- a/docker-compose.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-version: '3'
-services:
-    hydro:
-        image: hydrooj/hydro:latest
-        restart: always
-        links:
-        - mongo
-        volumes: 
-        - ./data/config:/config
-        ports:
-        - 8888:8888
-    mongo:
-        image: mongo:latest
-        restart: always
-        volumes:
-        - ./data/db:/data/db
diff --git a/hydro/model/discussion.ts b/hydro/model/discussion.ts
index 4e23b7cd3..320e19351 100644
--- a/hydro/model/discussion.ts
+++ b/hydro/model/discussion.ts
@@ -137,7 +137,7 @@ export function getStatus(domainId: string, did: ObjectID, uid: number) {
     return document.getStatus(domainId, document.TYPE_DISCUSSION, did, uid);
 }
 
-export function addNode(domainId: string, _id: string, category: string, args: any) {
+export function addNode(domainId: string, _id: string, category: string, args: any = {}) {
     return document.add(
         domainId, category, 1, document.TYPE_DISCUSSION_NODE,
         _id, null, null, args,
diff --git a/package.json b/package.json
index 943bf0739..791245a34 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "hydrooj",
-  "version": "2.9.3",
+  "version": "2.9.4",
   "main": "dist/loader.js",
   "bin": "bin/hydrooj.js",
   "repository": "https://github.com/hydro-dev/Hydro.git",