diff --git a/lib/n_able_rails.rb b/lib/n_able_rails.rb
index b3cee0e..43eff84 100644
--- a/lib/n_able_rails.rb
+++ b/lib/n_able_rails.rb
@@ -1,4 +1,4 @@
-require "n_able_rails/version"
+require 'n_able_rails/version'
 require 'savon'
 
 module NAbleRails
@@ -11,6 +11,12 @@ def self.initialize(sas_url, username, password)
 
     # create a client for the service
     @client = Savon.client(wsdl: "#{sas_url}/dms/services/ServerEI?wsdl")
+    # test connection to the api
+    version_info
+  rescue HTTPI::SSLError, Timeout::Error, Errno::EINVAL, Errno::ECONNRESET,
+         EOFError, Net::HTTPBadResponse, Net::HTTPHeaderSyntaxError,
+         Net::ProtocolError, Errno::ECONNREFUSED => error
+    return error
   end
 
   # List all available operations for the api.
@@ -24,39 +30,78 @@ def self.version_info
   end
 
   def self.list_devices(customer_id)
-    @client.call(:device_list, message: { Username: @username, Password: @password, Settings:
-                                          { "@xsi:type" => "impl:ArrayOf_tns1_T_KeyPair", "@env:arrayType" => "impl:T_KeyPair[]",
-                                          Setting:{key: "customerID", value: customer_id} }
+    @client.call(:device_list, message: { Username: @username,
+                                          Password: @password,
+                                          Settings:
+                                          { '@xsi:type' => 'impl:ArrayOf_tns1_T_KeyPair',
+                                            '@env:arrayType' => 'impl:T_KeyPair[]',
+                                            Setting: { key: 'customerID',
+                                                       value: customer_id } }
                                         })
+  rescue Savon::SOAPFault => error
+    return 'Invalid username-password combination.' if error.to_hash[:fault][:detail].nil?
+    return "Customer with id #{customer_id} could not be found."
   end
 
   def self.get_device_info(device_id)
-    @client.call(:device_get, message: { Username: @username, Password: @password, Settings:
-                                { Setting:{key: "deviceID", value: device_id} }
-                                       } )
+    @client.call(:device_get, message: { Username: @username,
+                                         Password: @password,
+                                         Settings: { Setting: { key: 'deviceID',
+                                                                value: device_id } }
+                                       })
+  rescue Savon::SOAPFault => error
+    return "Device with id #{device_id} could not be found." if error.to_hash[:fault][:faultstring] == '5000 Query failed.'
+    return 'Invalid username-password combination.'
   end
 
   def self.list_device_property(device_id)
-    @client.call(:device_property_list, message: { Username: @username, Password: @password, DeviceIDs: { DeviceID: device_id}, DeviceNames:{}, FilterIDs:{}, FilterNames:{}, ReverseOrder: false })
+    @client.call(:device_property_list, message: { Username: @username,
+                                                   Password: @password,
+                                                   DeviceIDs: { DeviceID: device_id },
+                                                   DeviceNames: {},
+                                                   FilterIDs: {},
+                                                   FilterNames: {},
+                                                   ReverseOrder: false })
+  rescue Savon::SOAPFault => error
+    return "Device with id #{device_id} could not be found." if error.to_hash[:fault][:faultstring] == '5000 Query failed.'
+    return 'Invalid username-password combination.'
   end
 
   def self.list_customers
-    @client.call(:customer_list, message: { Username: @username, Password: @password, Settings: {  } })
+    @client.call(:customer_list, message: { Username: @username,
+                                            Password: @password,
+                                            Settings: {} })
+  rescue Savon::SOAPFault => error
+    return "Device with id #{device_id} could not be found." if error.to_hash[:fault][:faultstring] == '5000 Query failed.'
+    return 'Invalid username-password combination.'
   end
 
   def self.device_asset_info_export2ById(device_id)
-    @client.call(:device_asset_info_export2, message: { Version: "0.0", Username: @username, Password: @password, Settings:
-                                                        { Setting:{Key: 'TargetByDeviceID', Value: {Value: device_id} } }
-                                                      } )
+    @client.call(:device_asset_info_export2, message: { Version: '0.0',
+                                                        Username: @username,
+                                                        Password: @password,
+                                                        Settings: { Setting: { Key: 'TargetByDeviceID',
+                                                                               Value: { Value: device_id } } }
+                                                      })
+  rescue Savon::SOAPFault
+    return 'Invalid username-password combination.'
   end
 
-  def self.device_asset_info_export2()
-    @client.call(:device_asset_info_export2, message: { Version: "0.0", Username: @username, Password: @password })
+  def self.device_asset_info_export2
+    @client.call(:device_asset_info_export2, message: { Version: '0.0',
+                                                        Username: @username,
+                                                        Password: @password })
+  rescue Savon::SOAPFault
+    return 'Invalid username-password combination.'
   end
 
   def self.device_status(device_id)
-    @client.call(:device_get_status, message: { Username: @username, Password: @password, Settings:
-                                          { Setting:{key: "deviceID", value: device_id} }
-                                              } )
+    @client.call(:device_get_status, message: { Username: @username,
+                                                Password: @password,
+                                                Settings: { Setting: { key: 'deviceID',
+                                                                       value: device_id } }
+                                              })
+  rescue Savon::SOAPFault
+    return 'Invalid username-password combination.'
   end
 end
diff --git a/lib/n_able_rails/version.rb b/lib/n_able_rails/version.rb
index 487fc51..987e83a 100644
--- a/lib/n_able_rails/version.rb
+++ b/lib/n_able_rails/version.rb
@@ -1,3 +1,3 @@
 module NAbleRails
-  VERSION = "0.1.0"
+  VERSION = '0.1.1'.freeze
 end
diff --git a/n_able_rails.gemspec b/n_able_rails.gemspec
index 08c7ecb..3811907 100644
--- a/n_able_rails.gemspec
+++ b/n_able_rails.gemspec
@@ -4,23 +4,25 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'n_able_rails/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "n_able_rails"
+  spec.name          = 'n_able_rails'
   spec.version       = NAbleRails::VERSION
-  spec.authors       = ["Alex Myers"]
-  spec.email         = ["dev.alex.myers@gmail.com"]
-  spec.description   = "An Api wrapper for N-Able from SolarWinds"
+  spec.authors       = ['Alex Myers']
+  spec.email         = ['dev.alex.myers@gmail.com']
+  spec.description   = 'An Api wrapper for N-Able from SolarWinds'
 
   spec.summary       = %q{Ruby Wrapper for N-Able API}
-  spec.homepage      = "https://github.com/enspiresoftware/n_able_rails"
-  spec.license       = "MIT"
+  spec.homepage      = 'https://github.com/enspiresoftware/n_able_rails'
+  spec.license       = 'MIT'
 
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  spec.bindir        = "exe"
+  spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
-  spec.require_paths = ["lib"]
+  spec.require_paths = ['lib']
 
-  spec.add_development_dependency "bundler", '~> 0'
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency 'bundler', '~> 0'
+  spec.add_development_dependency 'rake', '~> 10.0'
+  spec.add_development_dependency 'minitest-rails'
+  spec.add_development_dependency 'minitest-emoji'
 
   spec.add_runtime_dependency      'savon', '~> 2.3'
   spec.add_runtime_dependency      'wasabi', '~> 3.2'