diff --git a/Gemfile.lock b/Gemfile.lock
index ddfb09b..33297e2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    u2f (0.2.1)
+    u2f (1.0.0)
 
 GEM
   remote: https://rubygems.org/
@@ -82,4 +82,4 @@ DEPENDENCIES
   u2f!
 
 BUNDLED WITH
-   1.11.0
+   1.12.3
diff --git a/example/Gemfile b/example/Gemfile
index 73e40be..8157f7b 100644
--- a/example/Gemfile
+++ b/example/Gemfile
@@ -17,4 +17,7 @@ gem 'dm-core'
 # Padrino Stable Gem
 gem 'padrino', '0.12.4'
 
+# To enable https
+gem 'thin'
+
 gem 'u2f'#, path: '../.'
diff --git a/example/Gemfile.lock b/example/Gemfile.lock
index 227ba34..6233a1e 100644
--- a/example/Gemfile.lock
+++ b/example/Gemfile.lock
@@ -11,6 +11,7 @@ GEM
     bcrypt (3.1.9)
     bcrypt-ruby (3.1.5)
       bcrypt (>= 3.1.3)
+    daemons (1.2.4)
     data_objects (0.10.14)
       addressable (~> 2.1)
     dm-aggregates (1.2.0)
@@ -41,6 +42,7 @@ GEM
       dm-core (~> 1.2.0)
     do_sqlite3 (0.10.14)
       data_objects (= 0.10.14)
+    eventmachine (1.2.3)
     fastercsv (1.5.5)
     haml (4.0.5)
       tilt
@@ -100,6 +102,10 @@ GEM
       rack-protection (~> 1.4)
       tilt (~> 1.3, >= 1.3.4)
     stringex (1.5.1)
+    thin (1.7.0)
+      daemons (~> 1.0, >= 1.0.9)
+      eventmachine (~> 1.0, >= 1.0.4)
+      rack (>= 1, < 3)
     thor (0.19.1)
     thread_safe (0.3.4)
     tilt (1.4.1)
@@ -128,4 +134,8 @@ DEPENDENCIES
   haml
   padrino (= 0.12.4)
   rake
+  thin
   u2f
+
+BUNDLED WITH
+   1.12.3
diff --git a/example/README.md b/example/README.md
index f0b8d23..39a84dd 100644
--- a/example/README.md
+++ b/example/README.md
@@ -1,5 +1,5 @@
 ```bash
 bundle install
 padrino rake db:migrate
-padrino start
+thin start --ssl --ssl-disable-verify
 ```
diff --git a/example/app/controllers/registrations.rb b/example/app/controllers/registrations.rb
index 67b0f49..2e68fe1 100644
--- a/example/app/controllers/registrations.rb
+++ b/example/app/controllers/registrations.rb
@@ -12,19 +12,19 @@
   post :index do
     response = U2F::RegisterResponse.load_from_json(params[:response])
 
-    reg = begin
-      u2f.register!(session[:challenges], response)
+    begin
+      reg = u2f.register!(session[:challenges], response)
+
+      Registration.create!(certificate: reg.certificate,
+                           key_handle:  reg.key_handle,
+                           public_key:  reg.public_key,
+                           counter:     reg.counter)
     rescue U2F::Error => e
       @error_message = "Unable to register: #{e.class.name}"
     ensure
       session.delete(:challenges)
     end
 
-    Registration.create!(certificate: reg.certificate,
-                         key_handle:  reg.key_handle,
-                         public_key:  reg.public_key,
-                         counter:     reg.counter)
-
     render 'authentications/show'
   end
 end
diff --git a/example/app/views/authentications/new.haml b/example/app/views/authentications/new.haml
index ebac786..d7abc18 100644
--- a/example/app/views/authentications/new.haml
+++ b/example/app/views/authentications/new.haml
@@ -33,8 +33,10 @@
     $error.style.display = 'block';
     $error.innerHTML = errorMap[code];
   };
+  var appId = signRequests[0].appId
+  var challenge = signRequests[0].challenge
 
-  u2f.sign(signRequests, function(signResponse) {
+  u2f.sign(appId, challenge, signRequests, function(signResponse) {
     var form, reg;
 
     if (signResponse.errorCode) {
diff --git a/example/app/views/layouts/application.html.erb b/example/app/views/layouts/application.html.erb
index aab2f88..27f0dfa 100644
--- a/example/app/views/layouts/application.html.erb
+++ b/example/app/views/layouts/application.html.erb
@@ -11,12 +11,12 @@
     <meta name="viewport" content="width=device-width, initial-scale=1">
 
     <%= stylesheet_link_tag '//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css' %>
-    <link href='http://fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,700' rel='stylesheet' type='text/css'>
+    <link href='//fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,700' rel='stylesheet' type='text/css'>
     <style type="text/css">
       body { font-family: 'Source Sans Pro', sans-serif; }
     </style>
-    <script src="chrome-extension://pfboblefjcgdjicmnffhdgionmgcdmne/u2f-api.js"></script>
     <%= javascript_include_tag 'application' %>
+    <%= javascript_include_tag 'u2f-api' %>
   </head>
   <body>
     <!--[if lt IE 7]>
diff --git a/example/app/views/registrations/new.haml b/example/app/views/registrations/new.haml
index 0f40943..53ff611 100644
--- a/example/app/views/registrations/new.haml
+++ b/example/app/views/registrations/new.haml
@@ -33,8 +33,9 @@
     $error.style.display = 'block';
     $error.innerHTML = errorMap[code];
   };
+  var appId = registerRequests[0].appId
 
-  u2f.register(registerRequests, signRequests, function(registerResponse) {
+  u2f.register(appId, registerRequests, signRequests, function(registerResponse) {
     var form, reg;
 
     if (registerResponse.errorCode) {
diff --git a/example/public/javascripts/u2f-api.js b/example/public/javascripts/u2f-api.js
new file mode 100644
index 0000000..9244d14
--- /dev/null
+++ b/example/public/javascripts/u2f-api.js
@@ -0,0 +1,748 @@
+//Copyright 2014-2015 Google Inc. All rights reserved.
+
+//Use of this source code is governed by a BSD-style
+//license that can be found in the LICENSE file or at
+//https://developers.google.com/open-source/licenses/bsd
+
+/**
+ * @fileoverview The U2F api.
+ */
+'use strict';
+
+
+/**
+ * Namespace for the U2F api.
+ * @type {Object}
+ */
+var u2f = u2f || {};
+
+/**
+ * FIDO U2F Javascript API Version
+ * @number
+ */
+var js_api_version;
+
+/**
+ * The U2F extension id
+ * @const {string}
+ */
+// The Chrome packaged app extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the package Chrome app and does not require installing the U2F Chrome extension.
+ u2f.EXTENSION_ID = 'kmendfapggjehodndflmmgagdbamhnfd';
+// The U2F Chrome extension ID.
+// Uncomment this if you want to deploy a server instance that uses
+// the U2F Chrome extension to authenticate.
+// u2f.EXTENSION_ID = 'pfboblefjcgdjicmnffhdgionmgcdmne';
+
+
+/**
+ * Message types for messsages to/from the extension
+ * @const
+ * @enum {string}
+ */
+u2f.MessageTypes = {
+    'U2F_REGISTER_REQUEST': 'u2f_register_request',
+    'U2F_REGISTER_RESPONSE': 'u2f_register_response',
+    'U2F_SIGN_REQUEST': 'u2f_sign_request',
+    'U2F_SIGN_RESPONSE': 'u2f_sign_response',
+    'U2F_GET_API_VERSION_REQUEST': 'u2f_get_api_version_request',
+    'U2F_GET_API_VERSION_RESPONSE': 'u2f_get_api_version_response'
+};
+
+
+/**
+ * Response status codes
+ * @const
+ * @enum {number}
+ */
+u2f.ErrorCodes = {
+    'OK': 0,
+    'OTHER_ERROR': 1,
+    'BAD_REQUEST': 2,
+    'CONFIGURATION_UNSUPPORTED': 3,
+    'DEVICE_INELIGIBLE': 4,
+    'TIMEOUT': 5
+};
+
+
+/**
+ * A message for registration requests
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   appId: ?string,
+ *   timeoutSeconds: ?number,
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fRequest;
+
+
+/**
+ * A message for registration responses
+ * @typedef {{
+ *   type: u2f.MessageTypes,
+ *   responseData: (u2f.Error | u2f.RegisterResponse | u2f.SignResponse),
+ *   requestId: ?number
+ * }}
+ */
+u2f.U2fResponse;
+
+
+/**
+ * An error object for responses
+ * @typedef {{
+ *   errorCode: u2f.ErrorCodes,
+ *   errorMessage: ?string
+ * }}
+ */
+u2f.Error;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {enum {BLUETOOTH_RADIO, BLUETOOTH_LOW_ENERGY, USB, NFC}}
+ */
+u2f.Transport;
+
+
+/**
+ * Data object for a single sign request.
+ * @typedef {Array<u2f.Transport>}
+ */
+u2f.Transports;
+
+/**
+ * Data object for a single sign request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string,
+ *   keyHandle: string,
+ *   appId: string
+ * }}
+ */
+u2f.SignRequest;
+
+
+/**
+ * Data object for a sign response.
+ * @typedef {{
+ *   keyHandle: string,
+ *   signatureData: string,
+ *   clientData: string
+ * }}
+ */
+u2f.SignResponse;
+
+
+/**
+ * Data object for a registration request.
+ * @typedef {{
+ *   version: string,
+ *   challenge: string
+ * }}
+ */
+u2f.RegisterRequest;
+
+
+/**
+ * Data object for a registration response.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: Transports,
+ *   appId: string
+ * }}
+ */
+u2f.RegisterResponse;
+
+
+/**
+ * Data object for a registered key.
+ * @typedef {{
+ *   version: string,
+ *   keyHandle: string,
+ *   transports: ?Transports,
+ *   appId: ?string
+ * }}
+ */
+u2f.RegisteredKey;
+
+
+/**
+ * Data object for a get API register response.
+ * @typedef {{
+ *   js_api_version: number
+ * }}
+ */
+u2f.GetJsApiVersionResponse;
+
+
+//Low level MessagePort API support
+
+/**
+ * Sets up a MessagePort to the U2F extension using the
+ * available mechanisms.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ */
+u2f.getMessagePort = function(callback) {
+  if (typeof chrome != 'undefined' && chrome.runtime) {
+    // The actual message here does not matter, but we need to get a reply
+    // for the callback to run. Thus, send an empty signature request
+    // in order to get a failure response.
+    var msg = {
+        type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+        signRequests: []
+    };
+    chrome.runtime.sendMessage(u2f.EXTENSION_ID, msg, function() {
+      if (!chrome.runtime.lastError) {
+        // We are on a whitelisted origin and can talk directly
+        // with the extension.
+        u2f.getChromeRuntimePort_(callback);
+      } else {
+        // chrome.runtime was available, but we couldn't message
+        // the extension directly, use iframe
+        u2f.getIframePort_(callback);
+      }
+    });
+  } else if (u2f.isAndroidChrome_()) {
+    u2f.getAuthenticatorPort_(callback);
+  } else if (u2f.isIosChrome_()) {
+    u2f.getIosPort_(callback);
+  } else {
+    // chrome.runtime was not available at all, which is normal
+    // when this origin doesn't have access to any extensions.
+    u2f.getIframePort_(callback);
+  }
+};
+
+/**
+ * Detect chrome running on android based on the browser's useragent.
+ * @private
+ */
+u2f.isAndroidChrome_ = function() {
+  var userAgent = navigator.userAgent;
+  return userAgent.indexOf('Chrome') != -1 &&
+  userAgent.indexOf('Android') != -1;
+};
+
+/**
+ * Detect chrome running on iOS based on the browser's platform.
+ * @private
+ */
+u2f.isIosChrome_ = function() {
+  return ["iPhone", "iPad", "iPod"].indexOf(navigator.platform) > -1;
+};
+
+/**
+ * Connects directly to the extension via chrome.runtime.connect.
+ * @param {function(u2f.WrappedChromeRuntimePort_)} callback
+ * @private
+ */
+u2f.getChromeRuntimePort_ = function(callback) {
+  var port = chrome.runtime.connect(u2f.EXTENSION_ID,
+      {'includeTlsChannelId': true});
+  setTimeout(function() {
+    callback(new u2f.WrappedChromeRuntimePort_(port));
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the Authenticator app.
+ * @param {function(u2f.WrappedAuthenticatorPort_)} callback
+ * @private
+ */
+u2f.getAuthenticatorPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedAuthenticatorPort_());
+  }, 0);
+};
+
+/**
+ * Return a 'port' abstraction to the iOS client app.
+ * @param {function(u2f.WrappedIosPort_)} callback
+ * @private
+ */
+u2f.getIosPort_ = function(callback) {
+  setTimeout(function() {
+    callback(new u2f.WrappedIosPort_());
+  }, 0);
+};
+
+/**
+ * A wrapper for chrome.runtime.Port that is compatible with MessagePort.
+ * @param {Port} port
+ * @constructor
+ * @private
+ */
+u2f.WrappedChromeRuntimePort_ = function(port) {
+  this.port_ = port;
+};
+
+/**
+ * Format and return a sign request compliant with the JS API version supported by the extension.
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatSignRequest_ =
+  function(appId, challenge, registeredKeys, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: challenge,
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+      signRequests: signRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_SIGN_REQUEST,
+    appId: appId,
+    challenge: challenge,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+/**
+ * Format and return a register request compliant with the JS API version supported by the extension..
+ * @param {Array<u2f.SignRequest>} signRequests
+ * @param {Array<u2f.RegisterRequest>} signRequests
+ * @param {number} timeoutSeconds
+ * @param {number} reqId
+ * @return {Object}
+ */
+u2f.formatRegisterRequest_ =
+  function(appId, registeredKeys, registerRequests, timeoutSeconds, reqId) {
+  if (js_api_version === undefined || js_api_version < 1.1) {
+    // Adapt request to the 1.0 JS API
+    for (var i = 0; i < registerRequests.length; i++) {
+      registerRequests[i].appId = appId;
+    }
+    var signRequests = [];
+    for (var i = 0; i < registeredKeys.length; i++) {
+      signRequests[i] = {
+          version: registeredKeys[i].version,
+          challenge: registerRequests[0],
+          keyHandle: registeredKeys[i].keyHandle,
+          appId: appId
+      };
+    }
+    return {
+      type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+      signRequests: signRequests,
+      registerRequests: registerRequests,
+      timeoutSeconds: timeoutSeconds,
+      requestId: reqId
+    };
+  }
+  // JS 1.1 API
+  return {
+    type: u2f.MessageTypes.U2F_REGISTER_REQUEST,
+    appId: appId,
+    registerRequests: registerRequests,
+    registeredKeys: registeredKeys,
+    timeoutSeconds: timeoutSeconds,
+    requestId: reqId
+  };
+};
+
+
+/**
+ * Posts a message on the underlying channel.
+ * @param {Object} message
+ */
+u2f.WrappedChromeRuntimePort_.prototype.postMessage = function(message) {
+  this.port_.postMessage(message);
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface. Works only for the
+ * onmessage event, which is hooked up to the chrome.runtime.Port.onMessage.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedChromeRuntimePort_.prototype.addEventListener =
+    function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message' || name == 'onmessage') {
+    this.port_.onMessage.addListener(function(message) {
+      // Emulate a minimal MessageEvent object
+      handler({'data': message});
+    });
+  } else {
+    console.error('WrappedChromeRuntimePort only supports onMessage');
+  }
+};
+
+/**
+ * Wrap the Authenticator app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_ = function() {
+  this.requestId_ = -1;
+  this.requestObject_ = null;
+}
+
+/**
+ * Launch the Authenticator intent.
+ * @param {Object} message
+ */
+u2f.WrappedAuthenticatorPort_.prototype.postMessage = function(message) {
+  var intentUrl =
+    u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ +
+    ';S.request=' + encodeURIComponent(JSON.stringify(message)) +
+    ';end';
+  document.location = intentUrl;
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedAuthenticatorPort_.prototype.getPortType = function() {
+  return "WrappedAuthenticatorPort_";
+};
+
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedAuthenticatorPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name == 'message') {
+    var self = this;
+    /* Register a callback to that executes when
+     * chrome injects the response. */
+    window.addEventListener(
+        'message', self.onRequestUpdate_.bind(self, handler), false);
+  } else {
+    console.error('WrappedAuthenticatorPort only supports message');
+  }
+};
+
+/**
+ * Callback invoked  when a response is received from the Authenticator.
+ * @param function({data: Object}) callback
+ * @param {Object} message message Object
+ */
+u2f.WrappedAuthenticatorPort_.prototype.onRequestUpdate_ =
+    function(callback, message) {
+  var messageObject = JSON.parse(message.data);
+  var intentUrl = messageObject['intentURL'];
+
+  var errorCode = messageObject['errorCode'];
+  var responseObject = null;
+  if (messageObject.hasOwnProperty('data')) {
+    responseObject = /** @type {Object} */ (
+        JSON.parse(messageObject['data']));
+  }
+
+  callback({'data': responseObject});
+};
+
+/**
+ * Base URL for intents to Authenticator.
+ * @const
+ * @private
+ */
+u2f.WrappedAuthenticatorPort_.INTENT_URL_BASE_ =
+  'intent:#Intent;action=com.google.android.apps.authenticator.AUTHENTICATE';
+
+/**
+ * Wrap the iOS client app with a MessagePort interface.
+ * @constructor
+ * @private
+ */
+u2f.WrappedIosPort_ = function() {};
+
+/**
+ * Launch the iOS client app request
+ * @param {Object} message
+ */
+u2f.WrappedIosPort_.prototype.postMessage = function(message) {
+  var str = JSON.stringify(message);
+  var url = "u2f://auth?" + encodeURI(str);
+  location.replace(url);
+};
+
+/**
+ * Tells what type of port this is.
+ * @return {String} port type
+ */
+u2f.WrappedIosPort_.prototype.getPortType = function() {
+  return "WrappedIosPort_";
+};
+
+/**
+ * Emulates the HTML 5 addEventListener interface.
+ * @param {string} eventName
+ * @param {function({data: Object})} handler
+ */
+u2f.WrappedIosPort_.prototype.addEventListener = function(eventName, handler) {
+  var name = eventName.toLowerCase();
+  if (name !== 'message') {
+    console.error('WrappedIosPort only supports message');
+  }
+};
+
+/**
+ * Sets up an embedded trampoline iframe, sourced from the extension.
+ * @param {function(MessagePort)} callback
+ * @private
+ */
+u2f.getIframePort_ = function(callback) {
+  // Create the iframe
+  var iframeOrigin = 'chrome-extension://' + u2f.EXTENSION_ID;
+  var iframe = document.createElement('iframe');
+  iframe.src = iframeOrigin + '/u2f-comms.html';
+  iframe.setAttribute('style', 'display:none');
+  document.body.appendChild(iframe);
+
+  var channel = new MessageChannel();
+  var ready = function(message) {
+    if (message.data == 'ready') {
+      channel.port1.removeEventListener('message', ready);
+      callback(channel.port1);
+    } else {
+      console.error('First event on iframe port was not "ready"');
+    }
+  };
+  channel.port1.addEventListener('message', ready);
+  channel.port1.start();
+
+  iframe.addEventListener('load', function() {
+    // Deliver the port to the iframe and initialize
+    iframe.contentWindow.postMessage('init', iframeOrigin, [channel.port2]);
+  });
+};
+
+
+//High-level JS API
+
+/**
+ * Default extension response timeout in seconds.
+ * @const
+ */
+u2f.EXTENSION_TIMEOUT_SEC = 30;
+
+/**
+ * A singleton instance for a MessagePort to the extension.
+ * @type {MessagePort|u2f.WrappedChromeRuntimePort_}
+ * @private
+ */
+u2f.port_ = null;
+
+/**
+ * Callbacks waiting for a port
+ * @type {Array<function((MessagePort|u2f.WrappedChromeRuntimePort_))>}
+ * @private
+ */
+u2f.waitingForPort_ = [];
+
+/**
+ * A counter for requestIds.
+ * @type {number}
+ * @private
+ */
+u2f.reqCounter_ = 0;
+
+/**
+ * A map from requestIds to client callbacks
+ * @type {Object.<number,(function((u2f.Error|u2f.RegisterResponse))
+ *                       |function((u2f.Error|u2f.SignResponse)))>}
+ * @private
+ */
+u2f.callbackMap_ = {};
+
+/**
+ * Creates or retrieves the MessagePort singleton to use.
+ * @param {function((MessagePort|u2f.WrappedChromeRuntimePort_))} callback
+ * @private
+ */
+u2f.getPortSingleton_ = function(callback) {
+  if (u2f.port_) {
+    callback(u2f.port_);
+  } else {
+    if (u2f.waitingForPort_.length == 0) {
+      u2f.getMessagePort(function(port) {
+        u2f.port_ = port;
+        u2f.port_.addEventListener('message',
+            /** @type {function(Event)} */ (u2f.responseHandler_));
+
+        // Careful, here be async callbacks. Maybe.
+        while (u2f.waitingForPort_.length)
+          u2f.waitingForPort_.shift()(u2f.port_);
+      });
+    }
+    u2f.waitingForPort_.push(callback);
+  }
+};
+
+/**
+ * Handles response messages from the extension.
+ * @param {MessageEvent.<u2f.Response>} message
+ * @private
+ */
+u2f.responseHandler_ = function(message) {
+  var response = message.data;
+  var reqId = response['requestId'];
+  if (!reqId || !u2f.callbackMap_[reqId]) {
+    console.error('Unknown or missing requestId in response.');
+    return;
+  }
+  var cb = u2f.callbackMap_[reqId];
+  delete u2f.callbackMap_[reqId];
+  cb(response['responseData']);
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the sign request.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sign = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual sign request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0 : response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual sign request in the supported API version.
+    u2f.sendSignRequest(appId, challenge, registeredKeys, callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches an array of sign requests to available U2F tokens.
+ * @param {string=} appId
+ * @param {string=} challenge
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.SignResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendSignRequest = function(appId, challenge, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatSignRequest_(appId, challenge, registeredKeys, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * If the JS API version supported by the extension is unknown, it first sends a
+ * message to the extension to find out the supported API version and then it sends
+ * the register request.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.register = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  if (js_api_version === undefined) {
+    // Send a message to get the extension to JS API version, then send the actual register request.
+    u2f.getApiVersion(
+        function (response) {
+          js_api_version = response['js_api_version'] === undefined ? 0: response['js_api_version'];
+          console.log("Extension JS API Version: ", js_api_version);
+          u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+              callback, opt_timeoutSeconds);
+        });
+  } else {
+    // We know the JS API version. Send the actual register request in the supported API version.
+    u2f.sendRegisterRequest(appId, registerRequests, registeredKeys,
+        callback, opt_timeoutSeconds);
+  }
+};
+
+/**
+ * Dispatches register requests to available U2F tokens. An array of sign
+ * requests identifies already registered tokens.
+ * @param {string=} appId
+ * @param {Array<u2f.RegisterRequest>} registerRequests
+ * @param {Array<u2f.RegisteredKey>} registeredKeys
+ * @param {function((u2f.Error|u2f.RegisterResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.sendRegisterRequest = function(appId, registerRequests, registeredKeys, callback, opt_timeoutSeconds) {
+  u2f.getPortSingleton_(function(port) {
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var timeoutSeconds = (typeof opt_timeoutSeconds !== 'undefined' ?
+        opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC);
+    var req = u2f.formatRegisterRequest_(
+        appId, registeredKeys, registerRequests, timeoutSeconds, reqId);
+    port.postMessage(req);
+  });
+};
+
+
+/**
+ * Dispatches a message to the extension to find out the supported
+ * JS API version.
+ * If the user is on a mobile phone and is thus using Google Authenticator instead
+ * of the Chrome extension, don't send the request and simply return 0.
+ * @param {function((u2f.Error|u2f.GetJsApiVersionResponse))} callback
+ * @param {number=} opt_timeoutSeconds
+ */
+u2f.getApiVersion = function(callback, opt_timeoutSeconds) {
+ u2f.getPortSingleton_(function(port) {
+   // If we are using Android Google Authenticator or iOS client app,
+   // do not fire an intent to ask which JS API version to use.
+   if (port.getPortType) {
+     var apiVersion;
+     switch (port.getPortType()) {
+       case 'WrappedIosPort_':
+       case 'WrappedAuthenticatorPort_':
+         apiVersion = 1.1;
+         break;
+
+       default:
+         apiVersion = 0;
+         break;
+     }
+     callback({ 'js_api_version': apiVersion });
+     return;
+   }
+    var reqId = ++u2f.reqCounter_;
+    u2f.callbackMap_[reqId] = callback;
+    var req = {
+      type: u2f.MessageTypes.U2F_GET_API_VERSION_REQUEST,
+      timeoutSeconds: (typeof opt_timeoutSeconds !== 'undefined' ?
+          opt_timeoutSeconds : u2f.EXTENSION_TIMEOUT_SEC),
+      requestId: reqId
+    };
+    port.postMessage(req);
+  });
+};