diff --git a/lib/db.js b/lib/db.js
index a1fe32c..99d722a 100644
--- a/lib/db.js
+++ b/lib/db.js
@@ -1,12 +1,44 @@
-const Tapable = require('tapable')
+const { AsyncSeriesWaterfallHook } = require('tapable');
 
-class DB extends Tapable {
-  constructor() {
+class DB {
+  constructor(options) {
     // TODO
+    this.options =
+      Object.prototype.toString.call(options) === '[object Object]'
+        ? options
+        : {};
+    this.hooks = {
+      pluginHook: new AsyncSeriesWaterfallHook(['name']),
+    };
+  }
+  
+  plugin(name, cb) {
+    const { pluginHook } = this.hooks;
+    pluginHook.tapPromise(name, (options) => {
+      return new Promise(async (resolve, reject) => {
+        const isJudge = name === 'judge';
+        const cbBack = cb(options);
+        if (cbBack instanceof Promise) cbBack.catch((err) => reject(err));
+        let res = await cbBack;
+        let isErr = false;
+        if (res === true && isJudge) isErr = true;
+        if (res === true || isJudge) res = options;
+        if (isErr) reject(res);
+        else resolve(res);
+      });
+    });
   }
 
-  request() {
+  request(options) {
     // TODO
+    return new Promise((resolve, reject) => {
+      const { pluginHook } = this.hooks;
+      const optionsAssigned = Object.assign({}, this.options, options);
+      pluginHook
+        .promise(optionsAssigned)
+        .then((res) => resolve(res))
+        .catch((err) => reject(err));
+    });
   }
 }
 
diff --git a/package.json b/package.json
index aad5780..c0e6d62 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
     "webpack": "^3.5.3"
   },
   "dependencies": {
-    "puppeteer": "^16.2.0"
+    "puppeteer": "^16.2.0",
+    "tapable": "^2.2.1"
   }
 }