diff --git a/History.md b/History.md
index ec4ea53bf9..00861142fb 100644
--- a/History.md
+++ b/History.md
@@ -29,7 +29,8 @@
     
 * `webapp@1.12`
   - npm dependencies have been updated
-  - Added option to change runtime config in your app, [read more](https://github.com/meteor/meteor/pull/11506)
+  - Added hook to change runtime config delivered to the client app, [read more](https://github.com/meteor/meteor/pull/11506)
+  - Added hook to get notified when the app is updated, [read more](https://github.com/meteor/meteor/pull/11607)
   - `@vlasky/whomst@0.1.7`
   - Added `addUpdateNotifyHook` that gets called when runtime configuration is updated
   
diff --git a/packages/webapp/package.js b/packages/webapp/package.js
index f58b6b00f9..ee3e186368 100644
--- a/packages/webapp/package.js
+++ b/packages/webapp/package.js
@@ -35,6 +35,7 @@ Package.onUse(function (api) {
     'boilerplate-generator',
     'webapp-hashing',
     'inter-process-messaging',
+    'callback-hook'
   ], 'server');
 
   // At response serving time, webapp uses browser-policy if it is loaded. If
diff --git a/packages/webapp/webapp_server.js b/packages/webapp/webapp_server.js
index df91dbaa6a..a07b9cfff4 100644
--- a/packages/webapp/webapp_server.js
+++ b/packages/webapp/webapp_server.js
@@ -345,21 +345,35 @@ function getBoilerplate(request, arch) {
   return getBoilerplateAsync(request, arch).await();
 }
 
+/**
+ * @summary Takes a runtime configuration object and
+ * returns an encoded runtime string.
+ * @locus Server
+ * @param {Object} rtimeConfig
+ * @returns {String}
+*/
 WebApp.encodeRuntimeConfig = function (rtimeConfig) {
   return JSON.stringify(encodeURIComponent(JSON.stringify(rtimeConfig)));
 }
 
-WebApp.decodeRuntimeConfig = function (rtimeConfig) {
-  return JSON.parse(decodeURIComponent(JSON.parse(rtimeConfig)));
+/**
+ * @summary Takes an encoded runtime string and returns
+ * a runtime configuration object.
+ * @locus Server
+ * @param {String} rtimeConfigString
+ * @returns {Object}
+*/
+WebApp.decodeRuntimeConfig = function (rtimeConfigStr) {
+  return JSON.parse(decodeURIComponent(JSON.parse(rtimeConfigStr)));
 }
 
  const runtimeConfig = {
   // hooks will contain the callback functions
   // set by the caller to addRuntimeConfigHook
-  hooks: [],
+  hooks: new Hook(),
   // updateHooks will contain the callback functions
-  // set by the caller to addUpdatedConfigHook
-  updateHooks: [],
+  // set by the caller to addUpdatedNotifyHook
+  updateHooks: new Hook(),
   // isUpdatedByArch is an object containing fields for each arch 
   // that this server supports.
   // - Each field will be true when the server updates the runtimeConfig for that arch.
@@ -371,9 +385,55 @@ WebApp.decodeRuntimeConfig = function (rtimeConfig) {
   isUpdatedByArch: {}
 };
 
-WebApp.addRuntimeConfigHook = function (hook) {
-  if(typeof hook !== 'function') throw new Error('WebApp.addRuntimeConfigHook must be a function');
-  runtimeConfig.hooks.push(hook);
+/**
+ * @name addRuntimeConfigHookCallback(options)
+ * @locus Server
+ * @isprototype true
+ * @summary Callback for `addRuntimeConfigHook`.
+ * 
+ * If the handler returns a _falsy_ value the hook will not
+ * modify the runtime configuration.
+ * 
+ * If the handler returns a _String_ the hook will substitute
+ * the string for the encoded configuration string.
+ * 
+ * **Warning:** the hook does not check the return value at all it is
+ * the responsibility of the caller to get the formatting correct using
+ * the helper functions.
+ * 
+ * `addRuntimeConfigHookCallback` takes only one `Object` argument
+ * with the following fields:
+ * @param {Object} options
+ * @param {String} options.arch The architecture of the client
+ * requesting a new runtime configuration. This can be one of
+ * `web.browser`, `web.browser.legacy` or `web.cordova`.
+ * @param {Object} options.request
+ * A NodeJs [IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage)
+ * https://nodejs.org/api/http.html#http_class_http_incomingmessage
+ * `Object` that can be used to get information about the incoming request.
+ * @param {String} options.encodedCurrentConfig The current configuration object
+ * encoded as a string for inclusion in the root html.
+ * @param {Boolean} options.updated `true` if the config for this architecture
+ * has been updated since last called, otherwise `false`. This flag can be used
+ * to cache the decoding/encoding for each architecture.
+ */
+
+/**
+ * @summary Hook that calls back when the meteor runtime configuration,
+ * `__meteor_runtime_config__` is being sent to any client.
+ * 
+ * **returns**: <small>_Object_</small> `{ stop: function, callback: function }`
+ * - `stop` <small>_Function_</small> Call `stop()` to stop getting callbacks.
+ * - `callback` <small>_Function_</small> The passed in `callback`.
+ * @locus Server
+ * @param {addRuntimeConfigHookCallback} callback
+ * See `addRuntimeConfigHookCallback` description.
+ * @returns {Object} {{ stop: function, callback: function }}
+ * Call the returned `stop()` to stop getting callbacks.
+ * The passed in `callback` is returned also.
+*/
+WebApp.addRuntimeConfigHook = function (callback) {
+  return runtimeConfig.hooks.register(callback);
 }
 
 function getBoilerplateAsync(request, arch) {
@@ -415,14 +475,32 @@ function getBoilerplateAsync(request, arch) {
   }));
 }
 
-// Notification hook whenever the runtime configuration is updated
-// hook will pass an object with the following fields:
-// - arch
-// - manifest
-// - runtimeConfig
-WebApp.addUpdatedNotifyHook = function(hook) {
-  if(typeof hook !== 'function') throw new Error('WebApp.addUpdatedNotifyHook must be a function');
-  runtimeConfig.updateHooks.push(hook);
+/**
+ * @name addUpdatedNotifyHookCallback(options)
+ * @summary callback handler for `addupdatedNotifyHook`
+ * @isprototype true
+ * @locus Server
+ * @param {Object} options
+ * @param {String} options.arch The architecture that is being updated.
+ * This can be one of `web.browser`, `web.browser.legacy` or `web.cordova`.
+ * @param {Object} options.manifest The new updated manifest object for
+ * this `arch`.
+ * @param {Object} options.runtimeConfig The new updated configuration
+ * object for this `arch`.
+ */
+
+
+/**
+ * @summary Hook that runs when the meteor runtime configuration
+ * is updated.  Typically the configuration only changes during development mode.
+ * @locus Server
+ * @param {addUpdatedNotifyHookCallback} handler 
+ * The `handler` is called on every change to an `arch` runtime configuration.
+ * See `addUpdatedNotifyHookCallback`.
+ * @returns {Object} {{ stop: function, callback: function }}
+*/
+WebApp.addUpdatedNotifyHook = function(handler) {
+  return runtimeConfig.updateHooks.register(handler);
 }
 
 WebAppInternals.generateBoilerplateInstance = function (arch,
@@ -1032,6 +1110,44 @@ function runWebAppServer() {
   // other handlers added by package and application code.
   app.use(WebAppInternals.meteorInternalHandlers = connect());
 
+
+  /**
+   * @name connectHandlersCallback(req, res, next)
+   * @locus Server
+   * @isprototype true
+   * @summary callback handler for `WebApp.connectHandlers`
+   * @param {Object} req
+   * a Node.js
+   * [IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage)
+   * object with some extra properties. This argument can be used
+   *  to get information about the incoming request.
+   * @param {Object} res
+   * a Node.js
+   * [ServerResponse](http://nodejs.org/api/http.html#http_class_http_serverresponse)
+   * object. Use this to write data that should be sent in response to the
+   * request, and call `res.end()` when you are done.
+   * @param {Function} next
+   * Calling this function will pass on the handling of
+   * this request to the next relevant handler.
+   * 
+   */
+
+  /**
+   * @method connectHandlers
+   * @memberof WebApp
+   * @locus Server
+   * @summary Register a handler for all HTTP requests.
+   * @param {String} [path]
+   * This handler will only be called on paths that match
+   * this string. The match has to border on a `/` or a `.`.
+   * 
+   * For example, `/hello` will match `/hello/world` and
+   * `/hello.world`, but not `/hello_world`.
+   * @param {connectHandlersCallback} handler
+   * A handler function that will be called on HTTP requests.
+   * See `connectHandlersCallback`
+   * 
+   */
   // Packages and apps can add handlers to this via WebApp.connectHandlers.
   // They are inserted before our default handler.
   var packageAndAppHandlers = connect();