diff --git a/tsconfig.json b/tsconfig.json
index 8a6f9631..0853593e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -17,5 +17,5 @@
     "strictPropertyInitialization": true,
     "strictNullChecks": true
   },
-  "include": ["src/**/*.ts", "tests/**/*.ts", "demo/**/*.ts"]
+  "include": ["web/static/**/*.ts"]
 }
diff --git a/web/index.html b/web/index.html
index 5b0b4b81..fdccdfe2 100644
--- a/web/index.html
+++ b/web/index.html
@@ -5,6 +5,7 @@
     <title>Odoo Web Core Demo</title>
     <script src="/web/static/libs/almond/almond.js"></script>
     <script src="/main.js"></script>
+    <link rel="icon" href="data:,">
     <link rel="stylesheet" href="/app.css">
     <script>
         require('main');
diff --git a/web/static/src/ts/core/Widget.ts b/web/static/src/ts/core/Widget.ts
index 33261899..32d05746 100644
--- a/web/static/src/ts/core/Widget.ts
+++ b/web/static/src/ts/core/Widget.ts
@@ -1,35 +1,32 @@
-import QWeb from "./qweb_vdom";
-
 import { init } from "../../../libs/snabbdom/src/snabbdom";
 import sdListeners from "../../../libs/snabbdom/src/modules/eventlisteners";
 import sdAttrs from "../../../libs/snabbdom/src/modules/attributes";
 import { VNode } from "../../../libs/snabbdom/src/vnode";
+import QWeb from "./qweb_vdom";
 
 const patch = init([sdListeners, sdAttrs]);
 
-export interface Env {
+export interface WidgetEnv {
   qweb: QWeb;
-  services: { [key: string]: any };
-  [key: string]: any;
 }
 
-export default class Widget {
+export default class Widget<T extends WidgetEnv> {
   name: string = "widget";
   template: string = "<div></div>";
   vnode: VNode | null = null;
 
-  parent: Widget | null = null;
-  children: Widget[] = [];
-  env: Env;
+  parent: Widget<T> | null = null;
+  children: Widget<T>[] = [];
+  env: T;
   el: HTMLElement | null = null;
   state: Object = {};
-  refs: { [key: string]: Widget } = {};
+  refs: { [key: string]: Widget<T> } = {};
 
   //--------------------------------------------------------------------------
   // Lifecycle
   //--------------------------------------------------------------------------
 
-  constructor(parent: Widget | Env, props?: any) {
+  constructor(parent: Widget<T> | T, props?: any) {
     if (parent instanceof Widget) {
       this.parent = parent;
       parent.children.push(this);
@@ -99,7 +96,7 @@ export default class Widget {
     return vnode;
   }
 
-  private visitSubTree(callback: (w: Widget) => void) {
+  private visitSubTree(callback: (w: Widget<T>) => void) {
     callback(this);
     for (let child of this.children) {
       child.visitSubTree(callback);
diff --git a/web/static/src/ts/core/qweb_vdom.ts b/web/static/src/ts/core/qweb_vdom.ts
index 759bad52..5a0ff32a 100644
--- a/web/static/src/ts/core/qweb_vdom.ts
+++ b/web/static/src/ts/core/qweb_vdom.ts
@@ -2,13 +2,15 @@ import { VNode } from "../../../libs/snabbdom/src/vnode";
 import h from "../../../libs/snabbdom/src/h";
 
 export type EvalContext = { [key: string]: any };
-type RawTemplate = string;
-type ParsedTemplate = Document;
-type CompiledTemplate = (context: EvalContext) => VNode;
+export type RawTemplate = string;
+export type CompiledTemplate<T> = (context: EvalContext) => T;
+
 const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,this,typeof,eval,void,Math,RegExp,Array,Object,Date".split(
   ","
 );
 
+type ParsedTemplate = Document;
+
 // Compilation Context
 export class Context {
   nextID: number = 1;
@@ -84,7 +86,7 @@ export class Context {
 export default class QWeb {
   rawTemplates: { [name: string]: RawTemplate } = {};
   parsedTemplates: { [name: string]: ParsedTemplate } = {};
-  templates: { [name: string]: CompiledTemplate } = {};
+  templates: { [name: string]: CompiledTemplate<VNode> } = {};
   h = h;
   exprCache: { [key: string]: string } = {};
   directives: Directive[] = [];
@@ -183,7 +185,7 @@ export default class QWeb {
     return template(context);
   }
 
-  _compile(name: string): CompiledTemplate {
+  _compile(name: string): CompiledTemplate<VNode> {
     if (name in this.templates) {
       return this.templates[name];
     }
@@ -205,10 +207,9 @@ export default class QWeb {
         `Template: ${this.rawTemplates[name]}\nCompiled code:\n` + functionCode
       );
     }
-    const template: CompiledTemplate = (new Function(
-      "context",
-      functionCode
-    ) as CompiledTemplate).bind(this);
+    const template = (new Function("context", functionCode) as CompiledTemplate<
+      VNode
+    >).bind(this);
     this.templates[name] = template;
     return template;
   }
diff --git a/web/static/src/ts/env.ts b/web/static/src/ts/env.ts
index c4140778..5ac8fe4e 100644
--- a/web/static/src/ts/env.ts
+++ b/web/static/src/ts/env.ts
@@ -1,14 +1,12 @@
-import { Env } from "./core/Widget";
 import QWeb from "./core/qweb_vdom";
 import Router from "./services/router";
 import actions from "./services/actions";
-
-const qweb = new QWeb();
-const router = new Router();
+import { Env } from "./types";
 
 const env: Env = {
-  qweb: qweb,
-  services: { router, actions }
+  qweb: new QWeb(),
+  router: new Router(),
+  services: { actions }
 };
 
 export default env;
diff --git a/web/static/src/ts/main.ts b/web/static/src/ts/main.ts
index 46daa996..d2f14022 100644
--- a/web/static/src/ts/main.ts
+++ b/web/static/src/ts/main.ts
@@ -1,6 +1,6 @@
 ///<amd-module name="main" />
 
-import RootWidget from "./widgets/RootWidget";
+import RootWidget from "./widgets/root_widget";
 import env from "./env";
 
 document.addEventListener("DOMContentLoaded", async function() {
diff --git a/web/static/src/ts/services/actions.ts b/web/static/src/ts/services/actions.ts
index 7022a8a5..b453f1df 100644
--- a/web/static/src/ts/services/actions.ts
+++ b/web/static/src/ts/services/actions.ts
@@ -1,11 +1,14 @@
-import CRM from "../widgets/CRM";
-import Discuss from "../widgets/Discuss";
-import Widget from "../core/Widget";
+import CRM from "../widgets/crm";
+import Discuss from "../widgets/discuss";
+import Widget from "../core/widget";
+import { Env, Type } from "../types";
+
+
 
 export interface Action {
   id: number;
   title: string;
-  Widget: typeof Widget;
+  Widget: Type<Widget<Env>>;
   default?: boolean;
 }
 
@@ -15,3 +18,4 @@ const actions: Action[] = [
 ];
 
 export default actions;
+
diff --git a/web/static/src/ts/types.ts b/web/static/src/ts/types.ts
new file mode 100644
index 00000000..4337398d
--- /dev/null
+++ b/web/static/src/ts/types.ts
@@ -0,0 +1,11 @@
+import { WidgetEnv } from "./core/widget";
+import Router from "./services/router";
+
+export interface Env extends WidgetEnv {
+  router: Router;
+  services: { [key: string]: any };
+}
+
+export interface Type<T> extends Function {
+  new (...args: any[]): T;
+}
diff --git a/web/static/src/ts/widgets/CRM.ts b/web/static/src/ts/widgets/CRM.ts
index c2cfaea4..823e045a 100644
--- a/web/static/src/ts/widgets/CRM.ts
+++ b/web/static/src/ts/widgets/CRM.ts
@@ -1,4 +1,5 @@
-import Widget from "../core/Widget";
+import Widget from "../core/widget";
+import { Env } from "../types";
 
 const template = `
     <div class="o_crm">
@@ -6,7 +7,7 @@ const template = `
     </div>
 `;
 
-export default class Discuss extends Widget {
+export default class Discuss extends Widget<Env> {
   name = "crm";
   template = template;
 }
diff --git a/web/static/src/ts/widgets/Counter.ts b/web/static/src/ts/widgets/Counter.ts
index e6b4c8d3..fa7b5cde 100644
--- a/web/static/src/ts/widgets/Counter.ts
+++ b/web/static/src/ts/widgets/Counter.ts
@@ -1,4 +1,5 @@
-import Widget from "../core/Widget";
+import Widget from "../core/widget";
+import { Env } from "../types";
 
 const template = `
     <div>
@@ -8,14 +9,14 @@ const template = `
     </div>
 `;
 
-export default class Counter extends Widget {
+export default class Counter extends Widget<Env> {
   name = "counter";
   template = template;
   state = {
     counter: 0
   };
 
-  constructor(parent: Widget | null, props: {initialState?: number}) {
+  constructor(parent: Widget<Env>, props: {initialState?: number}) {
     super(parent);
     this.state.counter = props.initialState || 0;
   }
diff --git a/web/static/src/ts/widgets/Discuss.ts b/web/static/src/ts/widgets/Discuss.ts
index d132bac6..dbc2535e 100644
--- a/web/static/src/ts/widgets/Discuss.ts
+++ b/web/static/src/ts/widgets/Discuss.ts
@@ -1,5 +1,6 @@
-import Widget from "../core/Widget";
-import Counter from "./Counter";
+import Widget from "../core/widget";
+import Counter from "./counter";
+import { Env } from "../types";
 
 const template = `
     <div class="o_discuss">
@@ -18,7 +19,7 @@ const template = `
     </div>
 `;
 
-export default class Discuss extends Widget {
+export default class Discuss extends Widget<Env> {
   name = "discuss";
   template = template;
   widgets = { Counter };
diff --git a/web/static/src/ts/widgets/Navbar.ts b/web/static/src/ts/widgets/Navbar.ts
index b474a6e7..de5ea12a 100644
--- a/web/static/src/ts/widgets/Navbar.ts
+++ b/web/static/src/ts/widgets/Navbar.ts
@@ -1,5 +1,6 @@
-import Widget from "../core/Widget";
+import Widget from "../core/widget";
 import { Action } from "../services/actions";
+import { Env } from "../types";
 
 const template = `
     <div class="o_navbar">
@@ -12,12 +13,12 @@ const template = `
     </div>
 `;
 
-export default class Navbar extends Widget {
+export default class Navbar extends Widget<Env> {
   name = "navbar";
   template = template;
 
   getUrl(action: Action) {
-    const action_id = action.id;
-    return this.env.services.router.formatURL("web", { action_id });
+    const action_id = String(action.id);
+    return this.env.router.formatURL("web", { action_id });
   }
 }
diff --git a/web/static/src/ts/widgets/RootWidget.ts b/web/static/src/ts/widgets/root_widget.ts
similarity index 78%
rename from web/static/src/ts/widgets/RootWidget.ts
rename to web/static/src/ts/widgets/root_widget.ts
index d7747c1e..a2b042ba 100644
--- a/web/static/src/ts/widgets/RootWidget.ts
+++ b/web/static/src/ts/widgets/root_widget.ts
@@ -1,6 +1,7 @@
-import Widget, { Env } from "../core/Widget";
-import Navbar from "./Navbar";
+import Widget from "../core/widget";
+import Navbar from "./navbar";
 import { Action } from "../services/actions";
+import { Env } from "../types";
 
 const template = `
     <div class="o_web_client">
@@ -11,11 +12,10 @@ const template = `
     </div>
 `;
 
-export default class RootWidget extends Widget {
+export default class RootWidget extends Widget<Env> {
   name = "root";
   template = template;
   widgets = { Navbar };
-  state = { validcounter: true };
 
   constructor(env: Env) {
     super(env);
@@ -23,7 +23,7 @@ export default class RootWidget extends Widget {
   }
 
   mounted() {
-    this.env.services.router.register(this, this.onUrlChange);
+    this.env.router.register(this, this.onUrlChange);
   }
 
   setMainWidget() {
@@ -39,7 +39,7 @@ export default class RootWidget extends Widget {
   }
 
   getAction(): Action {
-    const routeInfo = this.env.services.router.getRouteInfo();
+    const routeInfo = this.env.router.getRouteInfo();
     const actionID = parseInt(routeInfo.query.action_id);
     let actions: Action[] = this.env.services.actions;
     let action = actions.find(a => a.id === actionID);
diff --git a/web/static/tests/qweb_vdom.test.ts b/web/static/tests/qweb_vdom.test.ts
index 3be4f494..e4fe75ce 100644
--- a/web/static/tests/qweb_vdom.test.ts
+++ b/web/static/tests/qweb_vdom.test.ts
@@ -1,4 +1,4 @@
-import QWeb, { EvalContext } from "../src/ts/core/qweb_vdom";
+import QWeb, {EvalContext} from "../src/ts/core/qweb_vdom";
 import { init } from "../libs/snabbdom/src/snabbdom";
 import sdAttributes from "../libs/snabbdom/src/modules/attributes";
 import sdListeners from "../libs/snabbdom/src/modules/eventlisteners";
diff --git a/web/static/tests/widget.test.ts b/web/static/tests/widget.test.ts
index 81563ff2..de7d8672 100644
--- a/web/static/tests/widget.test.ts
+++ b/web/static/tests/widget.test.ts
@@ -1,10 +1,14 @@
-import Widget from "../src/ts/core/Widget";
+import Widget, {WidgetEnv} from "../src/ts/core/widget";
 import QWeb from "../src/ts/core/qweb_vdom";
+import { Type } from "../src/ts/types";
 
-function makeWidget(W: typeof Widget): Widget {
+
+type TestEnv = WidgetEnv;
+type TestWidget = Widget<TestEnv>
+
+function makeWidget(W: Type<TestWidget>): TestWidget {
   const env = {
     qweb: new QWeb(),
-    services: {}
   };
   const w = new W(env);
   return w;
@@ -19,7 +23,7 @@ const template = `
     <div><t t-esc="state.counter"/><button t-on-click="inc">Inc</button></div>
 `;
 
-export default class Counter extends Widget {
+export default class Counter extends Widget<TestEnv> {
   name = "counter";
   template = template;
   state = {
@@ -54,7 +58,7 @@ describe("basic widget properties", () => {
   });
 
   test("widget style and classname", async () => {
-    class StyledWidget extends Widget {
+    class StyledWidget extends Widget<TestEnv> {
       template = `<div style="font-weight:bold;" class="some-class">world</div>`;
     }
     const widget = makeWidget(StyledWidget);
@@ -69,7 +73,7 @@ describe("basic widget properties", () => {
 describe("lifecycle hooks", () => {
   test("willStart hook is called", async () => {
     let willstart = false;
-    class HookWidget extends Widget {
+    class HookWidget extends Widget<TestEnv> {
       async willStart() {
         willstart = true;
       }
@@ -82,7 +86,7 @@ describe("lifecycle hooks", () => {
 
   test("mounted hook is not called if not in DOM", async () => {
     let mounted = false;
-    class HookWidget extends Widget {
+    class HookWidget extends Widget<TestEnv> {
       async mounted() {
         mounted = true;
       }
@@ -95,7 +99,7 @@ describe("lifecycle hooks", () => {
 
   test("mounted hook is called if mounted in DOM", async () => {
     let mounted = false;
-    class HookWidget extends Widget {
+    class HookWidget extends Widget<TestEnv> {
       async mounted() {
         mounted = true;
       }
@@ -112,7 +116,7 @@ describe("lifecycle hooks", () => {
     expect.assertions(2);
     let parentMounted = false;
     let childMounted = false;
-    class ParentWidget extends Widget {
+    class ParentWidget extends Widget<TestEnv> {
       name="a";
       template = `<div>Hello<t t-widget="child"/></div>`;
       widgets = { child: ChildWidget };
@@ -121,7 +125,7 @@ describe("lifecycle hooks", () => {
         parentMounted = true;
       }
     }
-    class ChildWidget extends Widget {
+    class ChildWidget extends Widget<TestEnv> {
       async mounted() {
         expect(parentMounted).toBe(true);
         childMounted = true;
@@ -147,13 +151,13 @@ describe("destroy method", () => {
 });
 
 describe("composition", () => {
-  class WidgetA extends Widget {
+  class WidgetA extends Widget<TestEnv> {
     name = "a";
     template = `<div>Hello<t t-widget="b"/></div>`;
     widgets = { b: WidgetB };
   }
 
-  class WidgetB extends Widget {
+  class WidgetB extends Widget<TestEnv> {
     template = `<div>world</div>`;
   }
 
@@ -165,7 +169,7 @@ describe("composition", () => {
   });
 
   test("t-refs on widget are widgets", async () => {
-    class WidgetC extends Widget {
+    class WidgetC extends Widget<TestEnv> {
       name = "a";
       template = `<div>Hello<t t-ref="mywidgetb" t-widget="b"/></div>`;
       widgets = { b: WidgetB };