diff --git a/docs/public-docs-package/index.js b/docs/public-docs-package/index.js
index 6a4782d6d1..54a3ae6665 100644
--- a/docs/public-docs-package/index.js
+++ b/docs/public-docs-package/index.js
@@ -5,6 +5,7 @@ module.exports = new Package('angular-v2-public-docs', [basePackage])
 
 .config(function(readTypeScriptModules) {
   readTypeScriptModules.sourceFiles = [
+    'angular2/lifecycle_hooks.ts',
     'angular2/metadata.ts',
     'angular2/change_detection.ts',
     'angular2/core.ts',
diff --git a/modules/angular2/angular2.ts b/modules/angular2/angular2.ts
index d59b9ad594..5bec573b44 100644
--- a/modules/angular2/angular2.ts
+++ b/modules/angular2/angular2.ts
@@ -15,3 +15,4 @@ export * from './forms';
 export * from './render';
 export * from './profile';
 export {bootstrap} from 'angular2/src/core/application';
+export * from './lifecycle_hooks';
diff --git a/modules/angular2/angular2_exports.ts b/modules/angular2/angular2_exports.ts
index b286e10836..088ab78d42 100644
--- a/modules/angular2/angular2_exports.ts
+++ b/modules/angular2/angular2_exports.ts
@@ -7,3 +7,4 @@ export * from './forms';
 export * from './render';
 export * from './profile';
 export {bootstrap} from 'angular2/src/core/application';
+export * from './lifecycle_hooks';
diff --git a/modules/angular2/lifecycle_hooks.ts b/modules/angular2/lifecycle_hooks.ts
new file mode 100644
index 0000000000..ce78f771f9
--- /dev/null
+++ b/modules/angular2/lifecycle_hooks.ts
@@ -0,0 +1,17 @@
+/**
+ * @module
+ * @description
+ * Defines interfaces to be implemented by directives when they need to hook into the change
+ * detection mechanism.
+ */
+
+export {
+  AfterContentInit,
+  AfterContentChecked,
+  AfterViewInit,
+  AfterViewChecked,
+  OnChanges,
+  OnDestroy,
+  OnInit,
+  DoCheck
+} from './src/core/compiler/interfaces';
diff --git a/modules/angular2/metadata.dart b/modules/angular2/metadata.dart
index 81484884f2..eb4c1f4399 100644
--- a/modules/angular2/metadata.dart
+++ b/modules/angular2/metadata.dart
@@ -1,4 +1,3 @@
 library angular2.metadata;
 
 export 'package:angular2/src/core/metadata.dart';
-export 'package:angular2/src/core/compiler/interfaces.dart';
diff --git a/modules/angular2/metadata.ts b/modules/angular2/metadata.ts
index 544d759b04..e0c8f2113c 100644
--- a/modules/angular2/metadata.ts
+++ b/modules/angular2/metadata.ts
@@ -3,10 +3,9 @@
  * @description
  *
  * Annotations provide the additional information that Angular requires in order to run your
- * application. This module
- * contains {@link ComponentMetadata}, {@link DirectiveMetadata}, and {@link ViewMetadata}
- * annotations, as well as
- * the {@link Host} annotation that is used by Angular to resolve dependencies.
+ * application. This module contains {@link ComponentMetadata}, {@link DirectiveMetadata}, and
+ * {@link ViewMetadata} annotations, as well as the {@link Host} annotation that is used by Angular
+ * to resolve dependencies.
  *
  */
 
@@ -48,17 +47,5 @@ export {
   HostListenerMetadata
 } from './src/core/metadata';
 
-export {
-  // todo(vbe): LifecycleHook should not be exposed (fails test.typings)
-  LifecycleHook,
-  AfterContentInit,
-  AfterContentChecked,
-  AfterViewInit,
-  AfterViewChecked,
-  OnChanges,
-  OnDestroy,
-  OnInit,
-  DoCheck
-} from './src/core/compiler/interfaces';
 
 export {Class, ClassDefinition, TypeDecorator} from './src/core/util/decorators';
diff --git a/modules/angular2/src/core/compiler/directive_lifecycle_reflector.dart b/modules/angular2/src/core/compiler/directive_lifecycle_reflector.dart
index 4f71a1fcec..b028ef8b2e 100644
--- a/modules/angular2/src/core/compiler/directive_lifecycle_reflector.dart
+++ b/modules/angular2/src/core/compiler/directive_lifecycle_reflector.dart
@@ -2,7 +2,7 @@ library angular2.src.core.compiler.directive_lifecycle_reflector;
 
 import 'package:angular2/src/core/reflection/reflection.dart';
 
-bool hasLifecycleHook(/*LifecycleHook*/ interface, type) {
+bool hasLifecycleHook(interface, type) {
   if (type is! Type) return false;
 
   return reflector.interfaces(type).contains(interface);
diff --git a/modules/angular2/src/core/compiler/directive_lifecycle_reflector.ts b/modules/angular2/src/core/compiler/directive_lifecycle_reflector.ts
index 5956e6f8da..c79bfeb8b2 100644
--- a/modules/angular2/src/core/compiler/directive_lifecycle_reflector.ts
+++ b/modules/angular2/src/core/compiler/directive_lifecycle_reflector.ts
@@ -1,7 +1,7 @@
 import {Type} from 'angular2/src/core/facade/lang';
 import * as Interfaces from './interfaces';
 
-export function hasLifecycleHook(lcInterface: Interfaces.LifecycleHook, type): boolean {
+export function hasLifecycleHook(lcInterface, type): boolean {
   if (!(type instanceof Type)) return false;
 
   var proto = (<any>type).prototype;
diff --git a/modules/angular2/src/core/compiler/interfaces.ts b/modules/angular2/src/core/compiler/interfaces.ts
index 85acc8c57d..7961cceb6d 100644
--- a/modules/angular2/src/core/compiler/interfaces.ts
+++ b/modules/angular2/src/core/compiler/interfaces.ts
@@ -8,10 +8,7 @@ import {StringMap} from 'angular2/src/core/facade/collection';
  * - `AfterContentInit`,
  * - `AfterContentChecked`,
  * - `OnDestroy` (at the very end before destruction)
- *
- * // todo(vicb): describe Dart & TS vs JS
  */
-export interface LifecycleHook {}
 
 /**
  * Notify a directive when any of its bindings have changed.
@@ -41,7 +38,7 @@ export interface LifecycleHook {}
  * }
  *  ```
  */
-export class OnChanges implements LifecycleHook {
+export class OnChanges {
   onChanges(changes: StringMap<string, any>): void {}
 }
 
@@ -63,7 +60,7 @@ export class OnChanges implements LifecycleHook {
  * }
  *  ```
  */
-export class OnInit implements LifecycleHook {
+export class OnInit {
   onInit(): void {}
 }
 
@@ -86,7 +83,7 @@ export class OnInit implements LifecycleHook {
  * }
  *  ```
  */
-export class DoCheck implements LifecycleHook {
+export class DoCheck {
   doCheck(): void {}
 }
 
@@ -104,7 +101,7 @@ export class DoCheck implements LifecycleHook {
  * }
  * ```
  */
-export class OnDestroy implements LifecycleHook {
+export class OnDestroy {
   onDestroy(): void {}
 }
 
@@ -122,7 +119,7 @@ export class OnDestroy implements LifecycleHook {
  * }
  *  ```
  */
-export class AfterContentInit implements LifecycleHook {
+export class AfterContentInit {
   afterContentInit(): void {}
 }
 
@@ -140,7 +137,7 @@ export class AfterContentInit implements LifecycleHook {
  * }
  *  ```
  */
-export class AfterContentChecked implements LifecycleHook {
+export class AfterContentChecked {
   afterContentChecked(): void {}
 }
 
@@ -158,7 +155,7 @@ export class AfterContentChecked implements LifecycleHook {
  * }
  *  ```
  */
-export class AfterViewInit implements LifecycleHook {
+export class AfterViewInit {
   afterViewInit(): void {}
 }
 
@@ -176,6 +173,6 @@ export class AfterViewInit implements LifecycleHook {
  * }
  *  ```
  */
-export class AfterViewChecked implements LifecycleHook {
+export class AfterViewChecked {
   afterViewChecked(): void {}
 }
diff --git a/modules/angular2/src/core/directives/ng_class.ts b/modules/angular2/src/core/directives/ng_class.ts
index 8c8bdf71b7..2a5fe65ec5 100644
--- a/modules/angular2/src/core/directives/ng_class.ts
+++ b/modules/angular2/src/core/directives/ng_class.ts
@@ -1,5 +1,6 @@
 import {isPresent, isString, StringWrapper, isBlank} from 'angular2/src/core/facade/lang';
-import {Directive, DoCheck, OnDestroy} from 'angular2/metadata';
+import {Directive} from 'angular2/metadata';
+import {DoCheck, OnDestroy} from 'angular2/lifecycle_hooks';
 import {ElementRef} from 'angular2/core';
 import {Renderer} from 'angular2/src/core/render/api';
 import {
diff --git a/modules/angular2/src/core/directives/ng_for.ts b/modules/angular2/src/core/directives/ng_for.ts
index 5bd763b08d..a2b74c638e 100644
--- a/modules/angular2/src/core/directives/ng_for.ts
+++ b/modules/angular2/src/core/directives/ng_for.ts
@@ -1,4 +1,5 @@
-import {Directive, DoCheck} from 'angular2/metadata';
+import {Directive} from 'angular2/metadata';
+import {DoCheck} from 'angular2/lifecycle_hooks';
 import {ViewContainerRef, ViewRef, TemplateRef} from 'angular2/core';
 import {ChangeDetectorRef, IterableDiffer, IterableDiffers} from 'angular2/change_detection';
 import {isPresent, isBlank} from 'angular2/src/core/facade/lang';
diff --git a/modules/angular2/src/core/directives/ng_style.ts b/modules/angular2/src/core/directives/ng_style.ts
index 75ddfafa5b..97d7ed9fb6 100644
--- a/modules/angular2/src/core/directives/ng_style.ts
+++ b/modules/angular2/src/core/directives/ng_style.ts
@@ -1,4 +1,5 @@
-import {Directive, DoCheck} from 'angular2/metadata';
+import {Directive} from 'angular2/metadata';
+import {DoCheck} from 'angular2/lifecycle_hooks';
 import {ElementRef} from 'angular2/core';
 import {KeyValueDiffer, KeyValueDiffers} from 'angular2/change_detection';
 import {isPresent, isBlank, print} from 'angular2/src/core/facade/lang';
diff --git a/modules/angular2/src/core/metadata/directives.ts b/modules/angular2/src/core/metadata/directives.ts
index 5f1f330ed7..4cbdb171df 100644
--- a/modules/angular2/src/core/metadata/directives.ts
+++ b/modules/angular2/src/core/metadata/directives.ts
@@ -318,6 +318,10 @@ import {ChangeDetectionStrategy} from 'angular2/change_detection';
  * the directive
  * controller is correctly instantiated on the `<template>` element rather than the `<li>` element.
  *
+ * ## Lifecycle hooks
+ *
+ * When the directive class implements some {@link angular2/lifecycle_hooks} the callbacks are
+ * called by the change detection at defined points in time during the life of the directive.
  *
  * ## Example
  *
@@ -734,6 +738,11 @@ export class DirectiveMetadata extends InjectableMetadata {
  *
  * For details on the `@View` annotation, see {@link ViewMetadata}.
  *
+ * ## Lifecycle hooks
+ *
+ * When the component class implements some {@link angular2/lifecycle_hooks} the callbacks are
+ * called by the change detection at defined points in time during the life of the component.
+ *
  * ## Example
  *
  * ```
diff --git a/modules/angular2/src/forms/directives/ng_control_group.ts b/modules/angular2/src/forms/directives/ng_control_group.ts
index e74005d795..819350a73e 100644
--- a/modules/angular2/src/forms/directives/ng_control_group.ts
+++ b/modules/angular2/src/forms/directives/ng_control_group.ts
@@ -1,4 +1,5 @@
-import {Directive, OnInit, OnDestroy} from 'angular2/metadata';
+import {Directive} from 'angular2/metadata';
+import {OnInit, OnDestroy} from 'angular2/lifecycle_hooks';
 import {Inject, Host, SkipSelf, forwardRef, Binding} from 'angular2/di';
 import {ListWrapper} from 'angular2/src/core/facade/collection';
 import {CONST_EXPR} from 'angular2/src/core/facade/lang';
diff --git a/modules/angular2/src/forms/directives/ng_control_name.ts b/modules/angular2/src/forms/directives/ng_control_name.ts
index 73332f835b..16887938a0 100644
--- a/modules/angular2/src/forms/directives/ng_control_name.ts
+++ b/modules/angular2/src/forms/directives/ng_control_name.ts
@@ -2,8 +2,9 @@ import {CONST_EXPR} from 'angular2/src/core/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/core/facade/async';
 import {StringMap} from 'angular2/src/core/facade/collection';
 
-import {Query, Directive, OnChanges, OnDestroy} from 'angular2/metadata';
+import {Query, Directive} from 'angular2/metadata';
 import {forwardRef, Host, SkipSelf, Binding, Inject, Optional} from 'angular2/di';
+import {OnChanges, OnDestroy} from 'angular2/lifecycle_hooks';
 
 import {ControlContainer} from './control_container';
 import {NgControl} from './ng_control';
diff --git a/modules/angular2/src/forms/directives/ng_form_control.ts b/modules/angular2/src/forms/directives/ng_form_control.ts
index 91b4adf7c7..64d83b7084 100644
--- a/modules/angular2/src/forms/directives/ng_form_control.ts
+++ b/modules/angular2/src/forms/directives/ng_form_control.ts
@@ -1,8 +1,9 @@
 import {CONST_EXPR} from 'angular2/src/core/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/core/facade/async';
 
-import {Query, Directive, OnChanges} from 'angular2/metadata';
+import {Query, Directive} from 'angular2/metadata';
 import {forwardRef, Binding, Inject, Optional} from 'angular2/di';
+import {OnChanges} from 'angular2/lifecycle_hooks';
 
 import {NgControl} from './ng_control';
 import {Control} from '../model';
diff --git a/modules/angular2/src/forms/directives/ng_form_model.ts b/modules/angular2/src/forms/directives/ng_form_model.ts
index 03fe47409e..5eb5f31ff4 100644
--- a/modules/angular2/src/forms/directives/ng_form_model.ts
+++ b/modules/angular2/src/forms/directives/ng_form_model.ts
@@ -2,7 +2,8 @@ import {CONST_EXPR} from 'angular2/src/core/facade/lang';
 import {ListWrapper} from 'angular2/src/core/facade/collection';
 import {ObservableWrapper, EventEmitter} from 'angular2/src/core/facade/async';
 
-import {Directive, OnChanges} from 'angular2/metadata';
+import {Directive} from 'angular2/metadata';
+import {OnChanges} from 'angular2/lifecycle_hooks';
 import {forwardRef, Binding} from 'angular2/di';
 import {NgControl} from './ng_control';
 import {NgControlGroup} from './ng_control_group';
diff --git a/modules/angular2/src/forms/directives/ng_model.ts b/modules/angular2/src/forms/directives/ng_model.ts
index cd517050f9..53d7373b60 100644
--- a/modules/angular2/src/forms/directives/ng_model.ts
+++ b/modules/angular2/src/forms/directives/ng_model.ts
@@ -1,8 +1,9 @@
 import {CONST_EXPR} from 'angular2/src/core/facade/lang';
 import {EventEmitter, ObservableWrapper} from 'angular2/src/core/facade/async';
 
-import {Query, Directive, OnChanges} from 'angular2/metadata';
+import {Query, Directive} from 'angular2/metadata';
 import {forwardRef, Binding, Inject, Optional} from 'angular2/di';
+import {OnChanges} from 'angular2/lifecycle_hooks';
 
 import {NgControl} from './ng_control';
 import {Control} from '../model';
diff --git a/modules/angular2/test/core/compiler/dynamic_component_loader_spec.ts b/modules/angular2/test/core/compiler/dynamic_component_loader_spec.ts
index c133b033a1..05630afb38 100644
--- a/modules/angular2/test/core/compiler/dynamic_component_loader_spec.ts
+++ b/modules/angular2/test/core/compiler/dynamic_component_loader_spec.ts
@@ -20,7 +20,8 @@ import {
 
 import {Injector} from 'angular2/di';
 import {NgIf} from 'angular2/directives';
-import {Component, View, ViewMetadata, OnDestroy} from 'angular2/metadata';
+import {Component, View, ViewMetadata} from 'angular2/metadata';
+import {OnDestroy} from 'angular2/lifecycle_hooks';
 import {DynamicComponentLoader} from 'angular2/src/core/compiler/dynamic_component_loader';
 import {ElementRef} from 'angular2/src/core/compiler/element_ref';
 import {DOCUMENT} from 'angular2/src/core/render/render';
diff --git a/modules/angular2/test/core/compiler/element_injector_spec.ts b/modules/angular2/test/core/compiler/element_injector_spec.ts
index f01d61e5cb..9bff98be77 100644
--- a/modules/angular2/test/core/compiler/element_injector_spec.ts
+++ b/modules/angular2/test/core/compiler/element_injector_spec.ts
@@ -35,9 +35,9 @@ import {
   Query,
   ViewQuery,
   ComponentMetadata,
-  DirectiveMetadata,
-  OnDestroy
+  DirectiveMetadata
 } from 'angular2/metadata';
+import {OnDestroy} from 'angular2/lifecycle_hooks';
 import {bind, Injector, Binding, Optional, Inject, Injectable, Self, SkipSelf, InjectMetadata, Host, HostMetadata, SkipSelfMetadata} from 'angular2/di';
 import {ViewContainerRef} from 'angular2/src/core/compiler/view_container_ref';
 import {TemplateRef} from 'angular2/src/core/compiler/template_ref';
diff --git a/modules/angular2/test/core/directive_lifecycle_integration_spec.ts b/modules/angular2/test/core/directive_lifecycle_integration_spec.ts
index 828b988398..e4d8a856b0 100644
--- a/modules/angular2/test/core/directive_lifecycle_integration_spec.ts
+++ b/modules/angular2/test/core/directive_lifecycle_integration_spec.ts
@@ -13,11 +13,8 @@ import {
   TestComponentBuilder
 } from 'angular2/test_lib';
 
+import {Directive, Component, View, ViewMetadata} from 'angular2/metadata';
 import {
-  Directive,
-  Component,
-  View,
-  ViewMetadata,
   OnChanges,
   OnInit,
   DoCheck,
@@ -25,7 +22,7 @@ import {
   AfterContentChecked,
   AfterViewInit,
   AfterViewChecked
-} from 'angular2/metadata';
+} from 'angular2/lifecycle_hooks';
 
 export function main() {
   describe('directive lifecycle integration spec', () => {
diff --git a/modules/angular2/web_worker/worker.ts b/modules/angular2/web_worker/worker.ts
index 76dfebf4c8..6292d5d337 100644
--- a/modules/angular2/web_worker/worker.ts
+++ b/modules/angular2/web_worker/worker.ts
@@ -1,4 +1,5 @@
 export * from '../metadata';
+export * from '../lifecycle_hooks';
 export * from '../change_detection';
 export * from '../core';
 export * from '../di';
@@ -7,6 +8,6 @@ export * from '../forms';
 export * from '../render';
 export * from '../profile';
 export * from '../src/web_workers/worker/application';
-export * from "../src/web_workers/shared/client_message_broker";
-export * from "../src/web_workers/shared/service_message_broker";
-export * from "../src/web_workers/shared/serializer";
+export * from '../src/web_workers/shared/client_message_broker';
+export * from '../src/web_workers/shared/service_message_broker';
+export * from '../src/web_workers/shared/serializer';
diff --git a/modules_dart/transform/lib/src/transform/common/interface_matcher.dart b/modules_dart/transform/lib/src/transform/common/interface_matcher.dart
index 90d2ebd56a..64a9b56c3a 100644
--- a/modules_dart/transform/lib/src/transform/common/interface_matcher.dart
+++ b/modules_dart/transform/lib/src/transform/common/interface_matcher.dart
@@ -11,53 +11,53 @@ export 'class_matcher_base.dart' show ClassDescriptor;
 /// covers all libraries which provide them.
 const _ON_CHANGE_INTERFACES = const [
   const ClassDescriptor('OnChanges', 'package:angular2/angular2.dart'),
-  const ClassDescriptor('OnChanges', 'package:angular2/metadata.dart'),
+  const ClassDescriptor('OnChanges', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'OnChanges', 'package:angular2/src/core/compiler/interfaces.dart'),
 ];
 const _ON_DESTROY_INTERFACES = const [
   const ClassDescriptor('OnDestroy', 'package:angular2/angular2.dart'),
-  const ClassDescriptor('OnDestroy', 'package:angular2/metadata.dart'),
+  const ClassDescriptor('OnDestroy', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'OnDestroy', 'package:angular2/src/core/compiler/interfaces.dart'),
 ];
 const _DO_CHECK_INTERFACES = const [
   const ClassDescriptor('DoCheck', 'package:angular2/angular2.dart'),
-  const ClassDescriptor('DoCheck', 'package:angular2/metadata.dart'),
+  const ClassDescriptor('DoCheck', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'DoCheck', 'package:angular2/src/core/compiler/interfaces.dart'),
 ];
 const _ON_INIT_INTERFACES = const [
   const ClassDescriptor('OnInit', 'package:angular2/angular2.dart'),
-  const ClassDescriptor('OnInit', 'package:angular2/metadata.dart'),
+  const ClassDescriptor('OnInit', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'OnInit', 'package:angular2/src/core/compiler/interfaces.dart'),
 ];
 const _ON_AFTER_CONTENT_INIT_INTERFACES = const [
   const ClassDescriptor('AfterContentInit', 'package:angular2/angular2.dart'),
   const ClassDescriptor(
-      'AfterContentInit', 'package:angular2/metadata.dart'),
+      'AfterContentInit', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'AfterContentInit', 'package:angular2/src/core/compiler/interfaces.dart')
 ];
 const _ON_AFTER_CONTENT_CHECKED_INTERFACES = const [
   const ClassDescriptor('AfterContentChecked', 'package:angular2/angular2.dart'),
   const ClassDescriptor(
-      'AfterContentChecked', 'package:angular2/metadata.dart'),
+      'AfterContentChecked', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'AfterContentChecked', 'package:angular2/src/core/compiler/interfaces.dart')
 ];
 const _ON_AFTER_VIEW_INIT_INTERFACES = const [
   const ClassDescriptor('AfterViewInit', 'package:angular2/angular2.dart'),
   const ClassDescriptor(
-      'AfterViewInit', 'package:angular2/metadata.dart'),
+      'AfterViewInit', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'AfterViewInit', 'package:angular2/src/core/compiler/interfaces.dart')
 ];
 const _ON_AFTER_VIEW_CHECKED_INTERFACES = const [
   const ClassDescriptor('AfterViewChecked', 'package:angular2/angular2.dart'),
   const ClassDescriptor(
-      'AfterViewChecked', 'package:angular2/metadata.dart'),
+      'AfterViewChecked', 'package:angular2/lifecycle_hooks.dart'),
   const ClassDescriptor(
       'AfterViewChecked', 'package:angular2/src/core/compiler/interfaces.dart')
 ];