diff --git a/build/buildModule.js b/build/buildModule.js
index 4a0e26c51..f44afb481 100644
--- a/build/buildModule.js
+++ b/build/buildModule.js
@@ -6,17 +6,11 @@ const zlib = require('zlib');
 const webpack = require('webpack');
 const yaml = require('js-yaml');
 const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin');
-const root = require('./root');
+const { root, exist } = require('./utils');
 const template = require('./template');
 
-const exist = (name) => {
-    try {
-        fs.statSync(root(name));
-    } catch (e) {
-        return false;
-    }
-    return true;
-};
+const prepare = ['model', 'lib', 'handler', 'service', 'script'];
+
 const build = async (type) => {
     const modules = fs.readdirSync(root('module'));
     const failed = [];
@@ -43,7 +37,6 @@ const build = async (type) => {
                     const builder = require(root(`module/${i}/build.js`));
                     if (builder.prebuild) await builder.prebuild();
                 }
-                const prepare = ['model', 'lib', 'handler', 'service'];
                 for (const j of prepare) {
                     if (exist(`module/${i}/${j}.js`)) {
                         const file = fs.readFileSync(root(`module/${i}/${j}.js`));
@@ -75,7 +68,6 @@ const build = async (type) => {
         if (!i.startsWith('.') && !failed.includes(i)) {
             try {
                 const current = {};
-                const prepare = ['model', 'lib', 'handler', 'service'];
                 for (const j of prepare) {
                     if (exist(`module/${i}/${j}.js`)) {
                         const file = fs.readFileSync(root(`module/${i}/${j}.js`));
diff --git a/build/index.js b/build/index.js
index 990ab9746..61f11c517 100644
--- a/build/index.js
+++ b/build/index.js
@@ -2,9 +2,8 @@ const fs = require('fs');
 const path = require('path');
 const zlib = require('zlib');
 const yaml = require('js-yaml');
-const root = require('./root');
+const { root, ignoreFailure, rmdir } = require('./utils');
 const template = require('./template');
-const ignoreFailure = require('./ignoreFailure');
 
 function getFiles(folder) {
     const res = [];
@@ -51,6 +50,11 @@ async function build(type) {
     fs.writeFileSync(root('.build/module/builtin.hydro'), data);
     await require('./buildModule')(type);
     await require('./webpack')(type);
+    const t = fs.readdirSync(root('.build/module'));
+    for (const f of t) {
+        if (fs.statSync(root(`.build/module/${f}`)).isDirectory()) rmdir(root(`.build/module/${f}`));
+    }
+    fs.unlinkSync(root('.build/builtin.json'));
 }
 
 module.exports = build;
diff --git a/build/root.js b/build/root.js
deleted file mode 100644
index 924d194a5..000000000
--- a/build/root.js
+++ /dev/null
@@ -1,6 +0,0 @@
-const path = require('path');
-
-function root(name) {
-    return path.resolve(__dirname, '..', name);
-}
-module.exports = root;
diff --git a/build/template.js b/build/template.js
index fe4dfcd87..4a0f2424e 100644
--- a/build/template.js
+++ b/build/template.js
@@ -1,5 +1,5 @@
 const fs = require('fs');
-const root = require('./root');
+const { root } = require('./utils');
 
 function getFiles(folder) {
     const files = [];
diff --git a/build/utils.js b/build/utils.js
new file mode 100644
index 000000000..9549f1793
--- /dev/null
+++ b/build/utils.js
@@ -0,0 +1,28 @@
+const fs = require('fs');
+const path = require('path');
+
+exports.root = (name) => path.resolve(__dirname, '..', name);
+exports.exist = (name) => {
+    try {
+        fs.statSync(exports.root(name));
+    } catch (e) {
+        return false;
+    }
+    return true;
+};
+exports.rmdir = function rmdir(p, recursive = true) {
+    if (!fs.existsSync(p)) return;
+    if (recursive) {
+        fs.readdirSync(p).forEach((file) => {
+            const curPath = `${p}/${file}`;
+            if (fs.statSync(curPath).isDirectory()) rmdir(curPath);
+            else fs.unlinkSync(curPath);
+        });
+    }
+    fs.rmdirSync(p);
+};
+exports.ignoreFailure = function ignoreFailure(func, ...params) {
+    try {
+        func(...params);
+    } catch (e) { } // eslint-disable-line no-empty
+};
diff --git a/build/webpack.js b/build/webpack.js
index 3f16590e9..684f1b1c7 100644
--- a/build/webpack.js
+++ b/build/webpack.js
@@ -2,7 +2,7 @@
 const fs = require('fs');
 const webpack = require('webpack');
 const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin');
-const root = require('./root');
+const { root } = require('./utils');
 
 const build = async (type) => {
     function hackNodeModuleFormidable() {
diff --git a/hydro/loader.js b/hydro/loader.js
index a7a2832b2..25f8c0353 100644
--- a/hydro/loader.js
+++ b/hydro/loader.js
@@ -21,6 +21,7 @@ function ensureDir(dir) {
 
 const active = [];
 try {
+    // eslint-disable-next-line import/no-unresolved
     const f = require('../.build/builtin.json');
     const m = { ...yaml.safeLoad(zlib.gunzipSync(f.data)), id: 'builtin' };
     active.push(m);
@@ -201,7 +202,11 @@ async function load() {
         handler: {},
         service: {},
         model: {},
+        script: {},
         lib: {},
+        nodeModules: {
+            mongodb: require('mongodb'),
+        },
         template: {},
         ui: {},
     };
diff --git a/module/migrate-vijos/handler.js b/module/migrate-vijos/handler.js
new file mode 100644
index 000000000..8239cdcca
--- /dev/null
+++ b/module/migrate-vijos/handler.js
@@ -0,0 +1,41 @@
+const {
+    Route, Connection, Handler, ConnectionHandler,
+} = global.Hydro.service.server;
+const { PERM_MANAGE } = global.Hydro.permission;
+const migrate = global.Hydro.script.migrateVijos;
+
+class MigrateVijosHandler extends Handler {
+    async prepare() {
+        this.checkPerm(PERM_MANAGE);
+    }
+
+    async get() {
+        const path = [
+            ['Hydro', '/'],
+            ['migrate_vijos', null],
+        ];
+        this.response.body = { path };
+        this.response.template = 'migrate_vijos.html';
+    }
+}
+
+class MigrateVijosConnectionHandler extends ConnectionHandler {
+    async prepare() {
+        this.checkPerm(PERM_MANAGE);
+    }
+
+    async message(msg) {
+        if (msg.key === 'start') {
+            migrate(msg, (data) => { this.send(data); });
+        }
+    }
+}
+
+async function apply() {
+    Route('/migrate/vijos', module.exports.MigrateVijosHandler);
+    Connection('/migrate/vijos-conn', module.exports.MigrateVijosConnectionHandler);
+}
+
+global.Hydro.handler.pastebin = module.exports = {
+    MigrateVijosHandler, MigrateVijosConnectionHandler, apply,
+};
diff --git a/module/migrate-vijos/hydro.json b/module/migrate-vijos/hydro.json
new file mode 100644
index 000000000..55a0cebdb
--- /dev/null
+++ b/module/migrate-vijos/hydro.json
@@ -0,0 +1,5 @@
+{
+    "name": "migrate-vijos",
+    "version": "0.0.1",
+    "description": "Migrate From Vijos"
+}
\ No newline at end of file
diff --git a/module/migrate-vijos/script.js b/module/migrate-vijos/script.js
new file mode 100644
index 000000000..732ff5b10
--- /dev/null
+++ b/module/migrate-vijos/script.js
@@ -0,0 +1,87 @@
+/* eslint-disable no-await-in-loop */
+const Mongo = global.Hydro.nodeModules.mongodb;
+const { ObjectID } = global.Hydro.nodeModules.bson;
+const dst = global.Hydro.service.db;
+
+function parseSolution(doc) {
+    return {
+        _id: doc._id,
+        title: doc.title,
+        content: doc.content,
+        vote: doc.vote,
+    };
+}
+
+async function problem(src, report) {
+    const count = await src.collection('document').find({ doc_type: 10 }).count();
+    report({ progress: 1, message: `Found ${count} problems.` });
+    for (let i = 0; i <= Math.floor(count / 50); i++) {
+        const docs = await src.collection('document').find({ doc_type: 10 })
+            .skip(i * 50).limit(50)
+            .toArray();
+        const problems = [];
+        for (const doc of docs) {
+            problems.push({
+                _id: doc._id,
+                pid: doc.doc_id || new ObjectID(),
+                title: doc.title,
+                content: doc.content,
+                owner: doc.owner_uid,
+                data: doc.data,
+                category: doc.category,
+                tag: doc.tag,
+                nSubmit: doc.num_submit,
+                nAccept: doc.num_accept,
+            });
+        }
+        await dst.collection('problem').insertMany(problems);
+    }
+}
+
+async function contest(src, report) {
+    const RULES = ['', 'oi', 'acm'];
+    const count = await src.collection('document').find({ doc_type: 30 }).count();
+    report({ progress: 1, message: `Found ${count} contests.` });
+    for (let i = 0; i <= Math.floor(count / 50); i++) {
+        const docs = await src.collection('document').find({ doc_type: 30 })
+            .skip(i * 50).limit(50)
+            .toArray();
+        const contests = [];
+        for (const doc of docs) {
+            contests.push({
+                _id: doc._id,
+                title: doc.title,
+                content: doc.content,
+                owner: doc.owner_uid,
+                rule: RULES[doc.rule],
+                beginAt: doc.begin_at,
+                endAt: doc.end_at,
+                pids: doc.pids,
+                attend: doc.attend,
+            });
+        }
+        await dst.collection('contests').insertMany(contests);
+    }
+}
+
+async function migrateVijos({
+    host, port, name, username, password,
+}, report = () => { }) {
+    let mongourl = 'mongodb://';
+    if (username) mongourl += `${username}:${password}@`;
+    mongourl += `${host}:${port}/${name}`;
+    const Database = await Mongo.MongoClient.connect(mongourl, {
+        useNewUrlParser: true, useUnifiedTopology: true,
+    });
+    const src = Database.db(name);
+    report({ progress: 0, message: 'Database connected.' });
+    dst.collection('system').insertOne({
+        _id: 'user',
+        value: (await src.collection('system').findOne({ _id: 'user_counter' })).value,
+    });
+    report({ progress: 1, message: 'Collection:system done.' });
+    await problem(src, report);
+    await contest(src, report);
+}
+
+global.Hydro.script.migrateVijos = module.exports = migrateVijos;
diff --git a/ui/build/main.js b/ui/build/main.js
index d89d0b55a..6c40bba34 100644
--- a/ui/build/main.js
+++ b/ui/build/main.js
@@ -5,9 +5,14 @@ import runGulp from './runGulp';
 import runWebpack from './runWebpack';
 
 async function main() {
+  const dir = process.cwd();
+  process.chdir(root());
   await runGulp(argv);
-  runWebpack(argv);
+  await runWebpack(argv);
+  process.chdir(dir);
 }
 
-process.chdir(root());
-main();
+module.exports = main;
+
+if (!module.parent) main();
+