diff --git a/lib/plugin.js b/lib/plugin.js
index 9bd34f1..83d160a 100644
--- a/lib/plugin.js
+++ b/lib/plugin.js
@@ -1,5 +1,49 @@
 import KY from 'ky-universal'
 
+// KY.prototype cannot be modified
+const KYExtra = {
+  setHeader(name, value, scopes = 'common') {
+    // for (let scope of Array.isArray(scopes) ? scopes : [scopes]) {
+    //   if (!value) {
+    //     delete this.defaults.headers[scope][name];
+    //     return
+    //   }
+    //   this.defaults.headers[scope][name] = value
+    // }
+  },
+  setToken(token, type, scopes = 'common') {
+    // const value = !token ? null : (type ? type + ' ' : '') + token
+    // this.setHeader('Authorization', value, scopes)
+  },
+  onRequest(fn) {
+    // this.interceptors.request.use(config => fn(config) || config)
+  },
+  onResponse(fn) {
+    // this.interceptors.response.use(response => fn(response) || response)
+  },
+  onRequestError(fn) {
+    // this.interceptors.request.use(undefined, error => fn(error) || Promise.reject(error))
+  },
+  onResponseError(fn) {
+    // this.interceptors.response.use(undefined, error => fn(error) || Promise.reject(error))
+  },
+  onError(fn) {
+    // this.onRequestError(fn)
+    // this.onResponseError(fn)
+  }
+}
+
+// Request helpers ($get, $post, ...)
+for (let method of ['get', 'post', 'put', 'patch', 'head', 'delete']) {
+  KYExtra['$' + method] = function () { return this[method].apply(this, arguments).then(res => res.json()) }
+}
+
+const extendKYInstance = instance => {
+  for (let key in KYExtra) {
+    instance[key] = KYExtra[key].bind(instance)
+  }
+}
+
 export default (ctx, inject) => {
   // Set baseURL
   const baseURL = process.browser
@@ -8,7 +52,7 @@ export default (ctx, inject) => {
 
   const kyDefaults = {
     baseURL,
-    headers
+    headers: {}
   }
 
   <% if (options.proxyHeaders) { %>
@@ -25,7 +69,10 @@ export default (ctx, inject) => {
   // Extend ky with defaults
   const ky = KY.extend(kyDefaults)
 
+  // Extend instance proto
+  extendKYInstance(ky)
+
   // Inject http to the context as $http
   ctx.$http = ky
-  inject('http', http)
+  inject('http', ky)
 }