diff --git a/authenticators/DigestAuthenticator.cls b/authenticators/DigestAuthenticator.cls
index cf1c3bda..783287a2 100644
--- a/authenticators/DigestAuthenticator.cls
+++ b/authenticators/DigestAuthenticator.cls
@@ -95,6 +95,7 @@ End Sub
 
 Private Sub IAuthenticator_AfterExecute(ByVal Client As RestClient, ByVal Request As RestRequest, ByRef Response As RestResponse)
     If Response.StatusCode = 401 And Not Me.IsAuthenticated Then
+        RestHelpers.LogDebug "Extract Authenticate and retry 401 request " & Request.FullUrl(Client.BaseUrl), "Digest.AfterExecute"
         ExtractAuthenticateInformation Response
         
         Request.AddHeader "Authorization", CreateHeader(Client, Request)
@@ -115,6 +116,7 @@ End Sub
 Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestClient, ByRef Request As RestRequest, BaseUrl As String, Optional UseAsync As Boolean = False)
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "DigestAuthenticator.HttpOpen"
 End Sub
 
 Public Function CreateHeader(Client As RestClient, Request As RestRequest) As String
@@ -131,6 +133,8 @@ Public Function CreateHeader(Client As RestClient, Request As RestRequest) As St
         ", cnonce=""" & Me.ClientNonce & """" & _
         ", response=""" & CalculateResponse(Client, Request) & """" & _
         ", opaque=""" & Me.Opaque & """"
+        
+    RestHelpers.LogDebug CreateHeader, "DigestAuthenticator.CreateHeader"
 End Function
 
 Public Function CalculateResponse(Client As RestClient, Request As RestRequest) As String
@@ -143,6 +147,7 @@ Public Function CalculateResponse(Client As RestClient, Request As RestRequest)
     HA2 = CalculateHA2(Request.MethodName, Uri)
     
     CalculateResponse = RestHelpers.MD5(HA1 & ":" & Me.ServerNonce & ":" & FormattedRequestCount & ":" & Me.ClientNonce & ":" & qop & ":" & HA2)
+    RestHelpers.LogDebug CalculateResponse, "DigestAuthenticator.CalculateResponse"
 End Function
 
 ' Extract authentication information from 401 response headers
@@ -172,6 +177,8 @@ Public Sub ExtractAuthenticateInformation(Response As RestResponse)
                     If Key = "nonce" Then Me.ServerNonce = Value
                     If Key = "opaque" Then Me.Opaque = Value
                 Next i
+                
+                RestHelpers.LogDebug "realm=" & Me.Realm & ", nonce=" & Me.ServerNonce & ", opaque=" & Me.Opaque, "DigestAuthenticator.ExtractAuthenticateInformation"
             End If
             
             Exit Sub
@@ -181,10 +188,12 @@ End Sub
 
 Public Function CalculateHA1() As String
     CalculateHA1 = MD5(Me.Username & ":" & Me.Realm & ":" & Me.Password)
+    RestHelpers.LogDebug CalculateHA1 & " for " & Me.Username & ":" & Me.Realm & ":" & RestHelpers.Obfuscate(Me.Password), "DigestAuthenticator.CalculateHA1"
 End Function
 
 Public Function CalculateHA2(Method As String, Uri As String) As String
     CalculateHA2 = MD5(Method & ":" & Uri)
+    RestHelpers.LogDebug CalculateHA2 & " for " & Method & ":" & Uri, "DigestAuthenticator.CalculateHA2"
 End Function
 
 ' Pad request count to 8 places
diff --git a/authenticators/EmptyAuthenticator.cls b/authenticators/EmptyAuthenticator.cls
index 0ab4686b..92f4115b 100644
--- a/authenticators/EmptyAuthenticator.cls
+++ b/authenticators/EmptyAuthenticator.cls
@@ -73,4 +73,5 @@ Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestCl
 
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "Authenticator.HttpOpen"
 End Sub
diff --git a/authenticators/FacebookAuthenticator.cls b/authenticators/FacebookAuthenticator.cls
index 51c7552d..1f1573fb 100644
--- a/authenticators/FacebookAuthenticator.cls
+++ b/authenticators/FacebookAuthenticator.cls
@@ -55,7 +55,9 @@ Public Property Get Token() As String
             EndIndex = InStr(StartIndex, Response.Content, "&expires=")
             
             pToken = Mid$(Response.Content, StartIndex, EndIndex - StartIndex)
+            RestHelpers.LogDebug "Received token: " & RestHelpers.Obfuscate(pToken), "FacebookAuthenticator.Token"
         Else
+            RestHelpers.LogError "Failed to load token: " & Response.StatusCode & " - " & Response.Content, "FacebookAuthenticator.Token"
             Err.Raise vbObjectError + Response.StatusCode, _
                 Description:="Failed to load Bearer Token: " & Response.StatusCode & " - " & Response.Content
         End If
@@ -95,6 +97,7 @@ Public Property Get LoginUrl()
         ScopeString = Me.Scope
     End If
     LoginUrl = LoginUrl & "&scope=" & ScopeString
+    RestHelpers.LogDebug LoginUrl, "FacebookAuthenticator.LoginUrl"
 End Property
 
 ' ============================================= '
@@ -140,6 +143,7 @@ Public Sub Login()
             Code = OAuthExtractCode(IE)
         Else
             ' Login failed
+            RestHelpers.LogError "Facebook login failed or was denied", "FacebookAuthenticator.Login"
             Err.Raise vbObjectError + 1, "OAuthDialog", "Login failed or was denied"
         End If
     End With
@@ -150,13 +154,16 @@ CleanUp:
     Set IE = Nothing
     
     If Not Completed Then
+        RestHelpers.LogError "Facebook login did not complete", "FacebookAuthenticator.Login"
         Err.Raise vbObjectError + 1, "OAuthDialog", "Login did not complete"
     ElseIf Err.Number <> 0 Then
         ' Rethrow error
         Err.Raise Err.Number, Err.Source, Err.Description
     ElseIf Left(Code, 5) = "Error" Then
+        RestHelpers.LogError "Facebook login returned error: " & Code, "FacebookAuthenticator.Login"
         Err.Raise vbObjectError + 1, "OAuthDialog", Code
     Else
+        RestHelpers.LogDebug "Successfully logged in: " & Code, "FacebookAuthenticator.Login"
         ' Success!
         Me.Code = Code
         
@@ -187,6 +194,7 @@ End Sub
 
 Private Sub IAuthenticator_BeforeExecute(ByVal Client As RestClient, ByRef Request As RestRequest)
     Request.AddQuerystringParam "access_token", Me.Token
+    RestHelpers.LogDebug "Add access_token=" & Me.Token, "FacebookAuthenticator.BeforeExecute"
 End Sub
 
 ''
@@ -214,6 +222,7 @@ End Sub
 Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestClient, ByRef Request As RestRequest, BaseUrl As String, Optional UseAsync As Boolean = False)
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Private Function TokenRequest() As RestRequest
@@ -267,6 +276,7 @@ Private Function OAuthExtractCode(IE As Object) As String
     If StartIndex >= 0 And EndIndex > StartIndex Then
         OAuthExtractCode = Mid$(Url, StartIndex, EndIndex - StartIndex)
     Else
+        RestHelpers.LogError "Unrecognized token format: " & Url, "FacebookAuthenticator.OAuthExtractCode"
         OAuthExtractCode = "Error: Unrecognized token formatting"
     End If
 End Function
diff --git a/authenticators/GoogleAuthenticator.cls b/authenticators/GoogleAuthenticator.cls
index 5717f95f..7d1d0b11 100644
--- a/authenticators/GoogleAuthenticator.cls
+++ b/authenticators/GoogleAuthenticator.cls
@@ -110,6 +110,7 @@ Public Property Get LoginUrl() As String
     Request.AddQuerystringParam "scope", ScopeString
     
     LoginUrl = Request.FormattedResource
+    RestHelpers.LogDebug LoginUrl, "GoogleAuthenticator.LoginUrl"
     Set Request = Nothing
 End Property
 
@@ -129,7 +130,9 @@ Public Property Get Token() As String
             Dim Data As Object
             Set Data = RestHelpers.ParseJSON(Response.Content)
             pToken = Data("access_token")
+            RestHelpers.LogDebug "Received Token: " & RestHelpers.Obfuscate(pToken), "GoogleAuthenticator.Token"
         Else
+            RestHelpers.LogError "Failed to load token: " & Response.StatusCode & " - " & Response.Content, "GoogleAuthenticator.Token"
             Err.Raise vbObjectError + Response.StatusCode, _
                 Description:="Failed to load Bearer Token: " & Response.StatusCode & " - " & Response.Content
         End If
@@ -197,14 +200,17 @@ Public Sub Login(Optional APIKey As String = "")
             Completed = True
             If OAuthIsDenied(IE) Then
                 ' Login failed
+                RestHelpers.LogError "Login failed or was denied", "GoogleAuthenticator.Login"
                 Err.Raise vbObjectError + 1, "OAuthDialog", "Login failed or was denied"
             Else
                 Code = OAuthExtractCode(IE)
                 If Left(Code, 5) = "Error" Then
+                    RestHelpers.LogError "Login error: " & Code, "GoogleAuthenticator.Login"
                     Err.Raise vbObjectError + 1, "OAuthDialog", Code
                 Else
                     ' Success!
                     Me.AuthorizationCode = Code
+                    RestHelpers.LogDebug "Login success: " & Code, "GoogleAuthenticator.Login"
                     
                     ' Temporarily assign token to force request
                     Dim Token As String
@@ -220,6 +226,7 @@ CleanUp:
     Set IE = Nothing
     
     If Not Completed Then
+        RestHelpers.LogError "Login did not complete", "GoogleAuthenticator.Login"
         Err.Raise vbObjectError + 1, "OAuthDialog", "Login did not complete"
     ElseIf Err.Number <> 0 Then
         ' Rethrow error
@@ -305,8 +312,10 @@ End Sub
 Private Sub IAuthenticator_BeforeExecute(ByVal Client As RestClient, ByRef Request As RestRequest)
     If Me.APIKey <> "" Then
         Request.AddQuerystringParam "key", Me.APIKey
+        RestHelpers.LogDebug "Login with key: " & RestHelpers.Obfuscate(Me.APIKey), "GoogleAuthenticator.BeforeExecute"
     Else
         Request.AddHeader "Authorization", "Bearer " & Me.Token
+        RestHelpers.LogDebug "Login with token: " & RestHelpers.Obfuscate(Me.Token), "GoogleAuthenticator.BeforeExecute"
     End If
 End Sub
 
@@ -335,6 +344,7 @@ End Sub
 Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestClient, ByRef Request As RestRequest, BaseUrl As String, Optional UseAsync As Boolean = False)
     ' Perform standard http open
     Http.Open Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Private Function TokenRequest() As RestRequest
diff --git a/authenticators/HttpBasicAuthenticator.cls b/authenticators/HttpBasicAuthenticator.cls
index 9122440a..a654838d 100644
--- a/authenticators/HttpBasicAuthenticator.cls
+++ b/authenticators/HttpBasicAuthenticator.cls
@@ -86,6 +86,7 @@ Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestCl
     ' Use http open with username and password values set
     ' (This is used in addition to setting request header, as some services required this)
     Http.Open Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync, Me.Username, Me.Password
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Private Function CreateHeader() As String
diff --git a/authenticators/OAuth1Authenticator.cls b/authenticators/OAuth1Authenticator.cls
index fe306539..bc33e980 100644
--- a/authenticators/OAuth1Authenticator.cls
+++ b/authenticators/OAuth1Authenticator.cls
@@ -136,6 +136,7 @@ End Sub
 Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestClient, ByRef Request As RestRequest, BaseUrl As String, Optional UseAsync As Boolean = False)
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Public Function CreateHeader(Client As RestClient, Request As RestRequest) As String
@@ -180,6 +181,8 @@ Public Function CreateHeader(Client As RestClient, Request As RestRequest) As St
     Header = Header & "oauth_token=" & Chr(34) & Me.Token & Chr(34) & ", "
     Header = Header & "oauth_version=" & Chr(34) & "1.0" & Chr(34)
     CreateHeader = Header
+    
+    RestHelpers.LogDebug CreateHeader, "OAuth1Authenticator.CreateHeader"
 End Function
 
 Public Function CreateBaseString(Nonce As String, Timestamp As String, Client As RestClient, Request As RestRequest) As String
@@ -200,6 +203,7 @@ Public Function CreateBaseString(Nonce As String, Timestamp As String, Client As
     base = base & "&" & "oauth_version=1.0"
     
     CreateBaseString = Request.MethodName() & "&" & RestHelpers.UrlEncode(RequestUrl(Client, Request)) & "&" & RestHelpers.UrlEncode(base)
+    RestHelpers.LogDebug CreateBaseString, "OAuth1Authenticator.CreateBaseString"
 End Function
 
 Public Function RequestUrl(Client As RestClient, Request As RestRequest) As String
@@ -239,7 +243,11 @@ Public Function RequestParameters(Client As RestClient, Request As RestRequest)
     Dim Parts As Dictionary
     Set Parts = RestHelpers.UrlParts(Request.FullUrl(Client.BaseUrl))
     
-    RequestParameters = RestHelpers.UrlDecode(Replace(Parts("Querystring"), "?", ""))
+    ' Remove leading ?
+    RequestParameters = Replace(Parts("Querystring"), "?", "")
+    
+    ' Replace + for spaces with %20
+    RequestParameters = Replace(RequestParameters, "+", "%20")
 End Function
 
 Public Function CreateSigningKey() As String
@@ -248,6 +256,7 @@ End Function
 
 Public Function CreateSignature(base As String, signingKey As String) As String
     CreateSignature = RestHelpers.Base64_HMACSHA1(base, signingKey)
+    RestHelpers.LogDebug CreateSignature, "OAuth1Authenticator.CreateSignature"
 End Function
 
 Public Function CreateTimestamp() As String
diff --git a/authenticators/OAuth2Authenticator.cls b/authenticators/OAuth2Authenticator.cls
index 2103a11d..bd48ed4c 100644
--- a/authenticators/OAuth2Authenticator.cls
+++ b/authenticators/OAuth2Authenticator.cls
@@ -90,6 +90,7 @@ Private Sub IAuthenticator_BeforeExecute(ByVal Client As RestClient, ByRef Reque
         
         If Http.Status <> 200 Then
             ' Error getting OAuth2 token
+            RestHelpers.LogError "Token request failed: " & Http.Status & " - " & Http.ResponseText, "OAuth2Authenticator.BeforeExecute"
             Err.Raise vbObjectError + Http.Status, _
                 Description:="Failed to retrieve OAuth2 Token - " & Http.Status & ": " & Http.ResponseText
         End If
@@ -99,6 +100,7 @@ Private Sub IAuthenticator_BeforeExecute(ByVal Client As RestClient, ByRef Reque
         If Not Response Is Nothing Then
             If Response.Exists(Me.TokenKey) Then
                 Me.Token = Response(Me.TokenKey)
+                RestHelpers.LogDebug "Received token: " & RestHelpers.Obfuscate(Me.Token), "OAuth2Authenticator.BeforeExecute"
             End If
             
             ' (Salesforce specific, but shouldn't affect any other OAuth2 clients)
@@ -106,6 +108,7 @@ Private Sub IAuthenticator_BeforeExecute(ByVal Client As RestClient, ByRef Reque
                 Request.BaseUrl = Response("instance_url")
             End If
         Else
+            RestHelpers.LogError "Failed to read OAuth2 Token: " & Http.ResponseText, "OAuth2Authenticator.BeforeExecute"
             Err.Raise vbObjectError + 2, _
                 Description:="Failed to read OAuth2 Token"
         End If
@@ -148,6 +151,7 @@ End Sub
 Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestClient, ByRef Request As RestRequest, BaseUrl As String, Optional UseAsync As Boolean = False)
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Private Function CreateHeader() As String
@@ -165,4 +169,5 @@ Private Function CreateTokenRequest() As String
     CreateTokenRequest = CreateTokenRequest & "&client_secret=" & Me.ClientSecret
     CreateTokenRequest = CreateTokenRequest & "&username=" & Me.Username
     CreateTokenRequest = CreateTokenRequest & "&password=" & Me.Password
+    RestHelpers.LogDebug CreateTokenRequest, "OAuth2Authenticator.CreateTokenRequest"
 End Function
diff --git a/authenticators/TwitterAuthenticator.cls b/authenticators/TwitterAuthenticator.cls
index 8fc0a6e0..84684b9a 100644
--- a/authenticators/TwitterAuthenticator.cls
+++ b/authenticators/TwitterAuthenticator.cls
@@ -48,7 +48,9 @@ Public Property Get Token() As String
         ' Store token if successful, otherwise throw error
         If Response.StatusCode = Ok Then
             pToken = Response.Data("access_token")
+            RestHelpers.LogDebug "Successfully received token: " & RestHelpers.Obfuscate(pToken), "TwitterAuthenticator.Token"
         Else
+            RestHelpers.LogError "Failed to load token: " & Response.StatusCode & " - " & Response.Content, "TwitterAuthenticator.Token"
             Err.Raise vbObjectError + Response.StatusCode, _
                 Description:="Failed to load Bearer Token: " & Response.StatusCode & " - " & Response.Content
         End If
@@ -121,6 +123,7 @@ Private Sub IAuthenticator_HttpOpen(ByRef Http As Object, ByVal Client As RestCl
 
     ' Perform standard http open
     Call Http.Open(Request.MethodName(), Request.FullUrl(BaseUrl), UseAsync)
+    RestHelpers.LogDebug "Http.Open " & Request.MethodName() & Request.FullUrl(BaseUrl), "FacebookAuthenticator.HttpOpen"
 End Sub
 
 Private Function TokenRequest() As RestRequest
diff --git a/specs/Excel-REST - Specs.xlsm b/specs/Excel-REST - Specs.xlsm
index 28b23c66..140f428d 100644
Binary files a/specs/Excel-REST - Specs.xlsm and b/specs/Excel-REST - Specs.xlsm differ
diff --git a/specs/OAuth1AuthenticatorSpecs.bas b/specs/OAuth1AuthenticatorSpecs.bas
index b503cfde..6c570f43 100644
--- a/specs/OAuth1AuthenticatorSpecs.bas
+++ b/specs/OAuth1AuthenticatorSpecs.bas
@@ -61,7 +61,17 @@ Public Function Specs() As SpecSuite
         Request.AddParameter "c", "Howdy!"
         Request.AddQuerystringParam "d", 789
         
-        .Expect(Auth.RequestParameters(Client, Request)).ToEqual "a=123&b=456&c=Howdy!&d=789"
+        .Expect(Auth.RequestParameters(Client, Request)).ToEqual "a=123&b=456&c=Howdy%21&d=789"
+    End With
+    
+    With Specs.It("should handle spaces in parameters correctly")
+        Client.BaseUrl = "http://localhost:3000/"
+        Set Request = New RestRequest
+        Request.Resource = "testing"
+        Request.AddQuerystringParam "a", "a b"
+        
+        .Expect(Auth.RequestParameters(Client, Request)).ToEqual "a=a%20b"
+        .Expect(Request.FullUrl(Client.BaseUrl)).ToEqual "http://localhost:3000/testing?a=a+b"
     End With
     
     Set Client = New RestClient
@@ -95,3 +105,67 @@ Public Function Specs() As SpecSuite
     
     InlineRunner.RunSuite Specs
 End Function
+
+' LinkedIn Specific
+' ----------------- '
+Sub LinkedInSpecs()
+    Dim Specs As New SpecSuite
+    
+    Dim Client As New RestClient
+    Client.BaseUrl = "http://api.linkedin.com/v1/"
+    
+    Dim Auth As New OAuth1Authenticator
+    Dim ConsumerKey As String
+    Dim ConsumerSecret As String
+    Dim Token As String
+    Dim TokenSecret As String
+    
+    If Credentials.Loaded Then
+        ConsumerKey = Credentials.Values("LinkedIn")("api_key")
+        ConsumerSecret = Credentials.Values("LinkedIn")("api_secret")
+        Token = Credentials.Values("LinkedIn")("user_token")
+        TokenSecret = Credentials.Values("LinkedIn")("user_secret")
+    Else
+        ConsumerKey = InputBox("Enter Consumer Key")
+        ConsumerSecret = InputBox("Enter Consumer Secret")
+        Token = InputBox("Enter Token")
+        TokenSecret = InputBox("Enter Token Secret")
+    End If
+    Auth.Setup _
+        ConsumerKey:=ConsumerKey, _
+        ConsumerSecret:=ConsumerSecret, _
+        Token:=Token, _
+        TokenSecret:=TokenSecret
+        
+    Set Client.Authenticator = Auth
+    
+    Dim Request As RestRequest
+    Dim Response As RestResponse
+    
+    With Specs.It("should get profile")
+        Set Request = New RestRequest
+        Request.Resource = "people/~?format={format}"
+        
+        Set Response = Client.Execute(Request)
+        
+        .Expect(Response.StatusCode).ToEqual 200
+        .Expect(Response.Data("firstName")).ToBeDefined
+    End With
+    
+    With Specs.It("should search with space")
+        Set Request = New RestRequest
+        Request.Resource = "company-search?format={format}"
+        Request.AddQuerystringParam "keywords", "microsoft corp"
+        
+        Set Response = Client.Execute(Request)
+        
+        .Expect(Response.StatusCode).ToEqual 200
+        .Expect(Response.Data("companies")).ToBeDefined
+        
+        If (Response.StatusCode <> 200) Then
+            Debug.Print "Error :" & Response.StatusCode & " - " & Response.Content
+        End If
+    End With
+    
+    InlineRunner.RunSuite Specs
+End Sub
diff --git a/src/RestClient.cls b/src/RestClient.cls
index a9fef6a0..b0c2375d 100644
--- a/src/RestClient.cls
+++ b/src/RestClient.cls
@@ -49,6 +49,7 @@ Public Function Execute(Request As RestRequest) As RestResponse
     On Error GoTo ErrorHandling
     Dim Http As Object
     
+    RestHelpers.LogDebug Request.FullUrl(Me.BaseUrl), "RestClient.Execute"
     Set Http = HttpSetup(Request, False)
     Set Execute = RestHelpers.ExecuteRequest(Http, Request)
     
@@ -79,6 +80,7 @@ Public Function ExecuteAsync(Request As RestRequest, Callback As String, Optiona
     Dim Http As Object
     
     ' Setup the request
+    RestHelpers.LogDebug Request.FullUrl(Me.BaseUrl), "RestClient.ExecuteAsync"
     Set Http = HttpSetup(Request, True)
     RestHelpers.ExecuteRequestAsync Http, Request, Me.TimeoutMS, Callback, CallbackArgs
     ExecuteAsync = True
@@ -110,7 +112,8 @@ Public Function GetJSON(Url As String, Optional Options As Dictionary) As RestRe
     Request.Format = json
     Request.Method = httpGET
     
-     Set GetJSON = Me.Execute(Request)
+    RestHelpers.LogDebug Request.FullUrl(Me.BaseUrl), "RestClient.GetJSON"
+    Set GetJSON = Me.Execute(Request)
 End Function
 
 ''
@@ -134,6 +137,7 @@ Public Function PostJSON(Url As String, Body As Dictionary, Optional Options As
     Request.Method = httpPOST
     Request.AddBody Body
     
+    RestHelpers.LogDebug Request.FullUrl(Me.BaseUrl), "RestClient.PostJSON"
     Set PostJSON = Me.Execute(Request)
 End Function
 
@@ -175,6 +179,7 @@ Private Function HttpSetup(ByRef Request As RestRequest, Optional UseAsync As Bo
     Else
         ' Nothing hooked in so open http object
         HttpSetup.Open Request.MethodName(), Request.FullUrl(Me.BaseUrl), UseAsync
+        RestHelpers.LogDebug "Http.Open " & Request.MethodName() & Request.FullUrl(Me.BaseUrl), "RestClient.HttpSetup"
     End If
     
     RestHelpers.SetHeaders HttpSetup, Request
diff --git a/src/RestHelpers.bas b/src/RestHelpers.bas
index c4c38563..6997caa9 100644
--- a/src/RestHelpers.bas
+++ b/src/RestHelpers.bas
@@ -67,10 +67,42 @@ Public Enum StatusCodes
     GatewayTimeout = 504
 End Enum
 
+Public EnableLogging As Boolean
+
 ' ============================================= '
 ' Shared Helpers
 ' ============================================= '
 
+''
+' Log helper
+'
+' @param {String} Message
+' @param {String} [From]
+' --------------------------------------------- '
+
+Public Sub LogDebug(Message As String, Optional From As String = "")
+    If EnableLogging Then
+        If From = "" Then
+            From = "Excel-REST"
+        End If
+        
+        Debug.Print From & ": " & Message
+    End If
+End Sub
+Public Sub LogError(Message As String, Optional From As String = "", Optional ErrNumber As Long = -1)
+    If From = "" Then
+        From = "Excel-REST"
+    End If
+    If ErrNumber >= 0 Then
+        From = From & ": " & ErrNumber
+    End If
+    
+    Debug.Print "ERROR - " & From & ": " & ErrNumber & " " & ErrDescription
+End Sub
+Public Function Obfuscate(Secure As String, Optional Character As String = "*") As String
+    Obfuscate = String(Len(Secure), Character)
+End Function
+
 ''
 ' Parse given JSON string into object (Dictionary or Collection)
 '
@@ -435,6 +467,7 @@ Public Function PrepareHttpRequest(Request As RestRequest, TimeoutMS As Long, _
     
     If Request.IncludeContentLength Then
         Request.AddHeader "Content-Length", Request.ContentLength
+        LogDebug "Content-Length: " & Request.ContentLength, "RestHelpers.PrepareHttpRequest"
     Else
         If Request.Headers.Exists("Content-Length") Then
             Request.Headers.Remove "Content-Length"
@@ -461,11 +494,13 @@ Public Sub SetHeaders(ByRef Http As Object, Request As RestRequest)
     Dim HeaderKey As Variant
     For Each HeaderKey In Request.Headers.Keys()
         Http.setRequestHeader HeaderKey, Request.Headers(HeaderKey)
+        LogDebug HeaderKey & ": " & Request.Headers(HeaderKey), "RestHelpers.SetHeaders"
     Next HeaderKey
     
     Dim CookieKey As Variant
     For Each CookieKey In Request.Cookies.Keys()
         Http.setRequestHeader "Cookie", CookieKey & "=" & Request.Cookies(CookieKey)
+        LogDebug "Cookie: " & CookieKey & "=" & Request.Cookies(CookieKey), "RestHelpers.SetHeaders"
     Next CookieKey
 End Sub
 
@@ -483,9 +518,11 @@ Public Sub PrepareProxyForHttpRequest(ByRef Http As Object, ProxyServer As Strin
     
     If ProxyServer <> "" Then
         Http.SetProxy 2, ProxyServer, BypassList
+        LogDebug "SetProxy: " & ProxyServer & ", " & BypassList, "RestHelpers.PrepareProxyForHttpRequest"
         
         If Username <> "" Then
             Http.SetProxyCredentials Username, Password
+            LogDebug "SetProxyCredentials: " & Username & ", " & Obfuscate(Password), "RestHelpers.PrepareProxyForHttpRequest"
         End If
     End If
 End Sub
@@ -504,6 +541,7 @@ Public Function ExecuteRequest(ByRef Http As Object, ByRef Request As RestReques
 
     ' Send the request and handle response
     Http.Send Request.Body
+    LogDebug "Http.Send: " & Request.Body, "RestHelpers.ExecuteRequest"
     Set Response = RestHelpers.CreateResponseFromHttp(Http, Request.Format)
     
 ErrorHandling:
@@ -513,9 +551,11 @@ ErrorHandling:
         If InStr(Err.Description, "The operation timed out") > 0 Then
             ' Return 408
             Set Response = RestHelpers.CreateResponse(StatusCodes.RequestTimeout, "Request Timeout")
+            LogDebug "Timeout: " & Request.FullUrl, "RestHelpers.ExecuteRequest"
             Err.Clear
         Else
             ' Rethrow error
+            LogError Err.Description, "RestHelpers.ExecuteRequest", Err.Number
             Err.Raise Err.Number, Description:=Err.Description
         End If
     End If
@@ -541,6 +581,7 @@ Public Sub ExecuteRequestAsync(ByRef Http As Object, ByRef Request As RestReques
     ' Send the request
     Request.StartTimeoutTimer TimeoutMS
     Http.Send Request.Body
+    LogDebug "Http.Send: " & Request.Body, "RestHelpers.ExecuteRequestAsync"
     
     Exit Sub
     
@@ -548,6 +589,7 @@ ErrorHandling:
 
     ' Close http and rethrow error
     If Not Http Is Nothing Then Set Http = Nothing
+    LogError Err.Description, "RestHelpers.ExecuteRequestAsync", Err.Number
     Err.Raise Err.Number, Description:=Err.Description
 End Sub
 
@@ -566,6 +608,8 @@ Public Function CreateResponseFromHttp(ByRef Http As Object, Optional Format As
     CreateResponseFromHttp.Body = Http.ResponseBody
     CreateResponseFromHttp.Content = Http.ResponseText
     
+    LogDebug "CreateResponse: " & Http.Status & ", " & Left(Http.ResponseText, 100), "RestHelpers.CreateResponseFromHttp"
+    
     ' Convert content to data by format
     Select Case Format
     Case AvailableFormats.formurlencoded
@@ -658,8 +702,10 @@ Public Function ExtractHeadersFromResponseHeaders(ResponseHeaders As String) As
                 ' Close out multi-line string
                 Multiline = False
                 Headers.Add Header
+                LogDebug Header("key") & "=" & Header("value"), "RestHelpers.ExtractHeadersFromResponseHeaders"
             ElseIf Not Header Is Nothing Then
                 Headers.Add Header
+                LogDebug Header("key") & "=" & Header("value"), "RestHelpers.ExtractHeadersFromResponseHeaders"
             End If
             
             If Not Multiline Then
@@ -771,6 +817,7 @@ Sub TimeoutTimerExpired(ByVal HWnd As Long, ByVal uMsg As Long, _
 #End If
     
     StopTimeoutTimer Request
+    LogDebug "Async Timeout: " & Request.FullUrl, "RestHelpers.TimeoutTimerExpired"
     Request.TimedOut
 End Sub
 
diff --git a/src/RestRequest.cls b/src/RestRequest.cls
index 34518210..2bd48622 100644
--- a/src/RestRequest.cls
+++ b/src/RestRequest.cls
@@ -139,6 +139,8 @@ Public Property Get FormattedResource() As String
             End If
         End If
     End If
+    
+    RestHelpers.LogDebug Me.Resource & " => " & FormattedResource, "RestRequest.FormattedResource"
 End Property
 
 Public Property Get Body() As String
@@ -169,6 +171,8 @@ Public Property Get Body() As String
             End Select
         End If
     End If
+    
+    RestHelpers.LogDebug Body, "RestRequest.Body"
 End Property
 
 Public Property Get FullUrl(Optional ClientBaseUrl As String = "") As String
@@ -195,6 +199,7 @@ Public Property Get FullUrl(Optional ClientBaseUrl As String = "") As String
     End If
     
     FullUrl = JoinUrl(Me.BaseUrl, Formatted)
+    RestHelpers.LogDebug Me.BaseUrl & " + " & Formatted & " => " & FullUrl, "RestRequest.FullUrl"
 End Property
 
 Public Property Get MethodName() As String
@@ -375,6 +380,7 @@ Attribute ReadyStateChangeHandler.VB_UserMemId = 0
     ' Once loaded, process result
     If Me.HttpRequest.readyState = 4 Then
         Me.StopTimeoutTimer
+        RestHelpers.LogDebug "ReadyState = 4", "RestRequest.ReadyStateChangeHandler"
         
         ' Callback
         RunCallback RestHelpers.CreateResponseFromHttp(Me.HttpRequest, Me.Format)
@@ -406,6 +412,7 @@ End Sub
 
 Public Sub TimedOut()
     ' Callback
+    RestHelpers.LogDebug "Timed out", "RestRequest.TimedOut"
     RunCallback RestHelpers.CreateResponse(StatusCodes.RequestTimeout, "Request Timeout")
 End Sub
 
@@ -440,6 +447,7 @@ Private Sub RunCallback(Response As RestResponse)
         Auth.AfterExecute Client, Me, Response
     End If
     If Me.Callback <> "" Then
+        RestHelpers.LogDebug Me.Callback, "RestRequest.RunCallback"
         If Not IsMissing(Me.CallbackArgs) Then
             Application.Run Me.Callback, Response, Me.CallbackArgs
         Else