I’m going to be frank, I don’t know what I’m doing but I’m hoping with a little help I can get there. I’ve been looking for a solution to the soon to be exiled AMTU application and decided to try to do it from scratch. I’ve been coding in VB and VBA since 1999 but I’ve only recently written a program to connect to a web API so my knowledge in this area is severely lacking.

I watched the whole Integrate with Amazon SP-API series and everything was going great until step 4B. In steps 1 to 3 I kind of felt a little like I was watching Dora the Explorer with the over explaining of each step multiple times. Then in step 4b they seem to jump through a series of authentication steps without a whole lot of explanation on any of it.

At any rate, here is what I have so far. It works as far as connecting to AP-SPI and retrieving the refresh token. I’m not sure what to do next. I believe I have to connect to AWS-STS to get the signed request using their encryption service or something… again, first time doing anything like this, I used to Username / Password and go!

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Private Sub cmdamazonspapi_Click()

Dim rs As dao.Recordset
Dim db As dao.Database
Dim WinHttp As New WinHttpRequest
Dim BodyStr As String
Dim refreshtoken As String
Dim clientid As String
Dim clientsecret As String
Dim expiredate As Date
Dim xamzdate As String

'Return Access token variables
Dim accesstoken As String
Dim tokentype As String
Dim expiresin As String

'API URI Variables
Dim apiuri As String

Set db = CurrentDb
Set rs = db.OpenRecordset(“select refreshtoken, clientid, clientsecret, accesstoken, expiredate from SPAPI”)
If rs.RecordCount = 0 Then Exit Sub

'Step 1 - Request Login with Amazon Access Token

'See if refresh token is still valid
refreshtoken = rs.Fields(“refreshtoken”)
clientid = rs.Fields(“clientid”)
clientsecret = rs.Fields(“clientsecret”)
If IsNull(rs.Fields(“accesstoken”)) Then Else accesstoken = rs.Fields(“accesstoken”)
If IsNull(rs.Fields(“expiredate”)) Then Else expiredate = rs.Fields(“expiredate”)

If DateDiff(“s”, Date & " " & Time, expiredate) > 0 Then
Debug.Print “Token still valid!”
Else 'If refresh token is not valid - get a new one!
'Our token has expired so get a new one!
BodyStr = “{” & Chr(34) & “grant_type” & Chr(34) & “:” & Chr(34) & “refresh_token” & Chr(34) & “,” & Chr(34) & “refresh_token” & Chr(34) & “:” & Chr(34) & refreshtoken & Chr(34) & “,” & Chr(34) & “client_id” & Chr(34) & “:” & Chr(34) & clientid & Chr(34) & “,”“client_secret”":" & Chr(34) & clientsecret & Chr(34) & “}”

'Debug.Print BodyStr

WinHttp.Open "POST", "https://api.amazon.com/auth/o2/token", False
WinHttp.SetRequestHeader "Content-Type", "application/json;charset=UTF-8"
WinHttp.Send BodyStr
'Debug.Print WinHttp.ResponseText
'Debug.Print WinHttp.Status

Dim dic As Object
Set dic = ParseJSON(WinHttp.ResponseText)
accesstoken = dic("obj.access_token")
If refreshtoken = dic("obj.refresh_token") Then
    'Token matches - there would be serious weirdness if it did not
Else
    MsgBox "Refresh Token mismatch!", vbOKOnly, "Token mismatch!"
End If
tokentype = dic("obj.token_type")
expiresin = dic("obj.expires_in")
expiredate = DateAdd("s", expiresin, Date & " " & Time)
CurrentDb.Execute "UPDATE SPAPI set accesstoken = '" & accesstoken & "', expiredate = #" & expiredate & "#"

End If

'Step 2 - Construct a Selling Partner API URI and connect to AWS-STS -

End Sub

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Right now it’s all coded under a button on my form. Oh and I use the VBA-JSON-PARSER module added in to my project, the person that coded that is truly a wizard. What I hope to accomplish is to be able to connect and update my inventory price and quantity. That’s it, that’s all I used AMTU for anything above and beyond that is just icing on the cake.

Any help would be greatly appreciated!