diff --git a/README.md b/README.md
index 53dfd07..0261d4a 100644
--- a/README.md
+++ b/README.md
@@ -73,14 +73,20 @@ to run the tests
 require 'ruby-bandwidth-iris'
 
 # Using  directly
-client = BandwidthIris::Client.new('accountId', 'userName', 'password')
+client = BandwidthIris::Client.new('accountId', 'userName', 'password') # Basic Auth
+client = BandwidthIris::Client.new({access_token: 'accessToken'}) # Bearer Token Auth
+client = BandwidthIris::Client.new({client_id: 'clientId', client_secret: 'clientSecret'}) # OAuth 2 using Client Credentials
 sites = BandwidthIris::Site.list(client)
 
 # Or you can use default client instance (do this only once)
 BandwidthIris::Client.global_options = {
   :account_id => 'accountId',
   :username => 'userName',
-  :password => 'password'
+  :password => 'password',
+  :access_token => 'accessToken',
+  :access_token_expiration => Time.now + 3600
+  :client_id => 'client_id',
+  :client_secret => 'client_secret'
 }
 
 # Now you can call any functions without first arg 'client'
diff --git a/lib/bandwidth-iris/client.rb b/lib/bandwidth-iris/client.rb
index 84185de..62e2e54 100644
--- a/lib/bandwidth-iris/client.rb
+++ b/lib/bandwidth-iris/client.rb
@@ -19,8 +19,12 @@ def initialize (account_id = nil, user_name = nil, password = nil, options = nil
       end
       options = options || @@global_options
       account_id = options[:account_id] unless account_id
-      user_name = options[:user_name] || options[:username]  unless user_name
+      user_name = options[:user_name] || options[:username] unless user_name
       password = options[:password] unless password
+      @access_token = options[:access_token]
+      @access_token_expiration = options[:access_token_expiration] || Time.now + 3600
+      @client_id = options[:client_id]
+      @client_secret = options[:client_secret]
       options[:api_endpoint] = @@global_options[:api_endpoint] unless options[:api_endpoint]
       options[:api_version] = @@global_options[:api_version] unless options[:api_version]
       api_endpoint = options[:api_endpoint] || "https://dashboard.bandwidth.com"
@@ -31,8 +35,15 @@ def initialize (account_id = nil, user_name = nil, password = nil, options = nil
       @create_connection = lambda{||
         Faraday.new(api_endpoint) { |faraday|
           # To make this gem compatible with Faraday v1 and v2, the basic_auth middleware can't be used because it was removed in v2
-          faraday.request :authorization, 'Basic', Base64.strict_encode64("#{user_name}:#{password}")
-          #faraday.response :logger
+          if @access_token && @access_token_expiration > Time.now + 60
+            faraday.request :authorization, 'Bearer', @access_token
+          elsif @client_id && @client_secret
+            refresh_auth_token
+            faraday.request :authorization, 'Bearer', @access_token
+          else
+            faraday.request :authorization, 'Basic', Base64.strict_encode64("#{user_name}:#{password}")
+          end
+          # faraday.response :logger
           faraday.headers['Accept'] = 'application/xml'
           faraday.headers['user-agent'] = 'Ruby-Bandwidth-Iris'
           faraday.response :follow_redirects # use Faraday::FollowRedirects::Middleware
@@ -67,9 +78,24 @@ def Client.get_id_from_location_header(location)
       items.last
     end
 
+    def refresh_auth_token
+      token_url = 'https://api.bandwidth.com/api/v1/oauth2/token'
+      response = Faraday.new do |faraday|
+        faraday.request :url_encoded
+        faraday.request :authorization, :basic, @client_id, @client_secret
+        @set_adapter.call(faraday)
+      end.post(token_url, {grant_type: 'client_credentials'})
+      if response.status >= 400
+        raise Errors::GenericError.new(response.status, response.reason_phrase, response.headers, response.body)
+      end
+      body = JSON.parse(response.body)
+      @access_token = body['access_token']
+      @access_token_expiration = Time.now + body['expires_in']
+    end
+
     # Make HTTP request to IRIS API
     # @param method [Symbol] http method to make
-    # @param path [string] path of url (exclude api verion and endpoint) to make call
+    # @param path [string] path of url (exclude api version and endpoint) to make call
     # @param data [Hash] data  which will be sent with request (for :get and :delete request they will be sent with query in url)
     # @return [Array] array with 2 elements: parsed  data of response and response headers
     def make_request(method, path, data = {})
@@ -89,7 +115,7 @@ def make_request(method, path, data = {})
 
     # Makes an HTTP request for file uploads
     # @param method [Symbol] http method to make
-    # @param path [string] path of url (exclude api verion and endpoint) to make call
+    # @param path [string] path of url (exclude api version and endpoint) to make call
     # @param data [string] the raw binary string representing the file to upload
     # @param content_type [string] the content type of the request
     # @return [Array] array with 2 elements: parsed  data of response and response headers
@@ -102,7 +128,7 @@ def make_request_file_upload(method, path, data, content_type)
 
     # Makes an HTTP request for a file download
     # @param method [Symbol] http method to make
-    # @param path [string] path of url (exclude api verion and endpoint) to make call
+    # @param path [string] path of url (exclude api version and endpoint) to make call
     # @param data [Hash] data  which will be sent with request (for :get and :delete request they will be sent with query in url)
     # @return [string] raw response from the API
     def make_request_file_download(method, path, data = {})
diff --git a/lib/bandwidth-iris/site.rb b/lib/bandwidth-iris/site.rb
index d6cb2c0..770ba59 100644
--- a/lib/bandwidth-iris/site.rb
+++ b/lib/bandwidth-iris/site.rb
@@ -39,7 +39,7 @@ def delete()
     def get_sip_peer(peer_id)
       item = @client.make_request(:get, "#{@client.concat_account_path(SITE_PATH)}/#{id}/sippeers/#{peer_id}")[0][:sip_peer]
       item[:site_id] = id
-      puts item
+      # puts item
       item
     end
 
diff --git a/lib/bandwidth-iris/version.rb b/lib/bandwidth-iris/version.rb
index 38f8315..ae7d4d7 100644
--- a/lib/bandwidth-iris/version.rb
+++ b/lib/bandwidth-iris/version.rb
@@ -1,4 +1,4 @@
 module BandwidthIris
   # Version of this gem
-  VERSION = "7.3.2"
+  VERSION = "7.4.0"
 end
diff --git a/spec/bandwidth-iris/client_spec.rb b/spec/bandwidth-iris/client_spec.rb
index a75e41b..03622d1 100644
--- a/spec/bandwidth-iris/client_spec.rb
+++ b/spec/bandwidth-iris/client_spec.rb
@@ -20,8 +20,8 @@
       expect(Client.get_id_from_location_header('http://localhost/path1/path2/id')).to eql('id')
     end
     it 'should raise error if location is missing or nil' do
-      expect{Client.get_id_from_location_header('')}.to raise_error
-      expect{Client.get_id_from_location_header(nil)}.to raise_error
+      expect{Client.get_id_from_location_header('')}.to raise_error(StandardError)
+      expect{Client.get_id_from_location_header(nil)}.to raise_error(StandardError)
     end
   end
 
@@ -51,12 +51,22 @@
 
   describe '#make_request' do
     client = nil
+    token_client = nil
+    expired_token_client = nil
+    client_credentials_client = nil
+
     before :each do
       client = Helper.get_client()
+      token_client = Helper.get_token_client()
+      expired_token_client = Helper.get_expired_token_client()
+      client_credentials_client = Helper.get_client_credentials_client()
     end
 
     after :each do
       client.stubs.verify_stubbed_calls()
+      token_client.stubs.verify_stubbed_calls()
+      expired_token_client.stubs.verify_stubbed_calls()
+      client_credentials_client.stubs.verify_stubbed_calls()
     end
 
     it 'should pass basic auth headers' do
@@ -65,6 +75,29 @@
       expect(client.make_request(:get, '/test-auth')).to eql([{:echoed_auth=>"Basic #{Base64.strict_encode64('username:password')}"}, {}])
     end
 
+    it 'should pass bearer auth header using token' do
+      token_client.stubs.get('/v1.0/test-auth-token') { |env| [200, {}, "<Result><EchoedAuth>#{env[:request_headers]['Authorization']}</EchoedAuth></Result>"] }
+      expect(token_client.make_request(:get, '/test-auth-token')).to eql([{:echoed_auth=>"Bearer accessToken"}, {}])
+      expect(token_client.instance_variable_get(:@access_token)).to eql('accessToken')
+      expect(token_client.instance_variable_get(:@access_token_expiration)).to be_a(Time)
+    end
+
+    it 'should refresh expired token and pass bearer auth header' do
+      expired_token_client.stubs.post('https://api.bandwidth.com/api/v1/oauth2/token') { |env| [200, {}, '{"access_token":"newAccessToken","expires_in":3600}'] }
+      expired_token_client.stubs.get('/v1.0/test-auth-expired-token') { |env| [200, {}, "<Result><EchoedAuth>#{env[:request_headers]['Authorization']}</EchoedAuth></Result>"] }
+      expect(expired_token_client.make_request(:get, '/test-auth-expired-token')).to eql([{:echoed_auth=>"Bearer newAccessToken"}, {}])
+      expect(expired_token_client.instance_variable_get(:@access_token)).to eql('newAccessToken')
+      expect(expired_token_client.instance_variable_get(:@access_token_expiration)).to be_a(Time)
+    end
+
+    it 'should use client credentials to get token and pass bearer auth header' do
+      client_credentials_client.stubs.post('https://api.bandwidth.com/api/v1/oauth2/token') { |env| [200, {}, '{"access_token":"clientCredentialsAccessToken","expires_in":3600}'] }
+      client_credentials_client.stubs.get('/v1.0/test-auth-client-credentials') { |env| [200, {}, "<Result><EchoedAuth>#{env[:request_headers]['Authorization']}</EchoedAuth></Result>"] }
+      expect(client_credentials_client.make_request(:get, '/test-auth-client-credentials')).to eql([{:echoed_auth=>"Bearer clientCredentialsAccessToken"}, {}])
+      expect(client_credentials_client.instance_variable_get(:@access_token)).to eql('clientCredentialsAccessToken')
+      expect(client_credentials_client.instance_variable_get(:@access_token_expiration)).to be_a(Time)
+    end
+
     it 'should make GET request and return xml  data' do
       client.stubs.get('/v1.0/path1') { |env| [200, {}, '<Result><Test>data</Test></Result>'] }
       client.stubs.get('/v1.0/path2?testField=10') { |env| [200, {'Location'=>'url'}, '<Root><TestValue>10</TestValue><DataArray>1</DataArray><DataArray>2</DataArray><BoolValue>true</BoolValue><BoolValue2>false</BoolValue2><DateTimeValue>2015-05-29T01:02:03Z</DateTimeValue></Root>'] }
diff --git a/spec/helper.rb b/spec/helper.rb
index eccfee3..cb47f4c 100644
--- a/spec/helper.rb
+++ b/spec/helper.rb
@@ -30,6 +30,23 @@ def self.get_client()
     Client.new('accountId', 'username', 'password')
   end
 
+  def self.get_token_client()
+    Client.new({access_token: 'accessToken'})
+  end
+
+  def self.get_expired_token_client()
+    Client.new({
+      access_token: 'expiredAccessToken',
+      access_token_expiration: Time.now - 3600,
+      client_id: 'clientId',
+      client_secret: 'clientSecret'
+    })
+  end
+
+  def self.get_client_credentials_client()
+    Client.new({client_id: 'clientId', client_secret: 'clientSecret'})
+  end
+
   def self.setup_environment()
     Client.global_options[:account_id] = 'accountId'
     Client.global_options[:username] = 'username'