diff --git a/lib/common/connection.js b/lib/common/connection.js
index 53680871532c..4fdd46e4678e 100644
--- a/lib/common/connection.js
+++ b/lib/common/connection.js
@@ -76,6 +76,7 @@ module.exports.Token = Token;
  *
  * @param {object} opts - Configuration options.
  * @param {array} opts.scopes - Scopes required for access.
+ * @param {object} opts.credentials - Credentials object.
  *
  * @example
  * var SCOPES = [
@@ -93,6 +94,11 @@ function Connection(opts) {
 
   this.isConnecting = false;
   this.waitQueue = [];
+
+  if (opts.credentials && opts.credentials.private_key &&
+      opts.credentials.client_email) {
+    this.credentials = opts.credentials;
+  }
 }
 
 /**
@@ -129,7 +135,7 @@ Connection.prototype.connect = function(callback) {
  */
 Connection.prototype.fetchToken = function(callback) {
   var that = this;
-  if (!this.opts.keyFilename) {
+  if (!this.opts.keyFilename && !this.credentials) {
     // We should be on GCE, try to retrieve token from the metadata server.
     req({
       method: 'get',
diff --git a/lib/datastore/dataset.js b/lib/datastore/dataset.js
index b53ea8122e87..475f69263b9d 100644
--- a/lib/datastore/dataset.js
+++ b/lib/datastore/dataset.js
@@ -76,8 +76,11 @@ var SCOPES = [
  * @param {object=} options
  * @param {string} options.projectId - Dataset ID. This is your project ID from
  *     the Google Developers Console.
- * @param {string} options.keyFilename - Full path to the JSON key downloaded
- *     from the Google Developers Console.
+ * @param {string=} options.keyFilename - Full path to the JSON key downloaded
+ *     from the Google Developers Console. Alternatively, you may provide a
+ *     `credentials` object.
+ * @param {object=} options.credentials - Credentials object, used in place of
+ *     a `keyFilename`.
  * @param {string} options.namespace - Namespace to isolate transactions to.
  *
  * @example
@@ -90,6 +93,7 @@ function Dataset(options) {
   options = options || {};
 
   this.connection = new conn.Connection({
+    credentials: options.credentials,
     keyFilename: options.keyFilename,
     scopes: SCOPES
   });
diff --git a/lib/pubsub/index.js b/lib/pubsub/index.js
index d977b690d7d1..8bbfe7c2cd1a 100644
--- a/lib/pubsub/index.js
+++ b/lib/pubsub/index.js
@@ -219,8 +219,11 @@ Topic.prototype.del = function(callback) {
  * Represents connection to Google Cloud Pub/Sub API.
  * @param {string} opts.projectId   Google Developers Console Project ID.
  * @param {string} opts.email       Service account email.
- * @param {string} opts.pemFilePath Path to the pem file that contains your
- *                                  private key.
+ * @param {string=} options.keyFilename - Full path to the JSON key downloaded
+ *     from the Google Developers Console. Alternatively, you may provide a
+ *     `credentials` object.
+ * @param {object=} options.credentials - Credentials object, used in place of
+ *     a `keyFilename`.
  */
 function Connection(opts) {
   opts = opts || {};
@@ -228,6 +231,7 @@ function Connection(opts) {
 
   this.id = id;
   this.conn = new conn.Connection({
+    credentials: opts.credentials,
     keyFilename: opts.keyFilename,
     scopes: SCOPES
   });
diff --git a/lib/storage/index.js b/lib/storage/index.js
index 61a866c76f17..9bf06fc4a4dc 100644
--- a/lib/storage/index.js
+++ b/lib/storage/index.js
@@ -92,8 +92,11 @@ BufferStream.prototype._read = function() {
  *
  * @param {object} options - Configuration options.
  * @param {string} options.bucketName - Name of the bucket.
- * @param {string} options.keyFilename - Full path to the JSON key downloaded
- *     from the Google Developers Console.
+ * @param {string=} options.keyFilename - Full path to the JSON key downloaded
+ *     from the Google Developers Console. Alternatively, you may provide a
+ *     `credentials` object.
+ * @param {object=} options.credentials - Credentials object, used in place of
+ *     a `keyFilename`.
  *
  * @example
  * var gcloud = require('gcloud');
@@ -117,6 +120,7 @@ function Bucket(options) {
   }
   this.bucketName = options.bucketName;
   this.conn = new conn.Connection({
+    credentials: options.credentials,
     keyFilename: options.keyFilename,
     scopes: SCOPES
   });
diff --git a/test/common/connection.js b/test/common/connection.js
index 8087774ce16b..6cf34e0850eb 100644
--- a/test/common/connection.js
+++ b/test/common/connection.js
@@ -26,6 +26,7 @@ var connection = require('../../lib/common/connection.js');
 
 describe('Connection', function() {
   var conn;
+  var privateKeyFileJson = require('../testdata/privateKeyFile.json');
 
   beforeEach(function() {
     conn = new connection.Connection({
@@ -34,7 +35,6 @@ describe('Connection', function() {
   });
 
   it('should use a private key json file', function(done) {
-    var privateKeyFileJson = require('../testdata/privateKeyFile.json');
     conn.fetchServiceAccountToken_ = function(callback) {
       callback(null);
     };
@@ -45,6 +45,13 @@ describe('Connection', function() {
     });
   });
 
+  it('should accept and assign credentials object', function() {
+    var credConnection = new connection.Connection({
+      credentials: privateKeyFileJson
+    });
+    assert.deepEqual(credConnection.credentials, privateKeyFileJson);
+  });
+
   describe('Token', function() {
     var tokenNeverExpires = new connection.Token('token', new Date(3000, 0, 0));
     var tokenExpired = new connection.Token('token', new Date(2011, 0, 0));