(Visual Basic 6.0) USPS OAuth2 Client Credentials

See more OAuth2 Examples

Get an OAuth2 access token for the United States Postal Service (USPS) REST API.

For more information, see https://developers.usps.com/api/81

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim http As New ChilkatHttp
Dim success As Long

' Implements the following CURL command:

' curl -X POST https://apis.usps.com/oauth2/v3/token \
'   -H "Content-Type: application/x-www-form-urlencoded" \
'   -d "grant_type=client_credentials" \
'   -d "client_id=123456789" \
'   -d "client_secret=A1B2C3D4E5" \
'   -d "scope=ResourceA+ResourceB+ResourceC"

' Use the following online tool to generate HTTP code from a CURL command
' Convert a cURL Command to HTTP Source Code

Dim req As New ChilkatHttpRequest
req.AddParam "grant_type","client_credentials"
req.AddParam "client_id","123456789"
req.AddParam "client_secret","A1B2C3D4E5"
req.AddParam "scope","ResourceA+ResourceB+ResourceC"

Dim resp As ChilkatHttpResponse
Set resp = http.PostUrlEncoded("https://apis.usps.com/oauth2/v3/token",req)
If (http.LastMethodSuccess = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

Dim sbResponseBody As New ChilkatStringBuilder
success = resp.GetBodySb(sbResponseBody)

Dim jResp As New ChilkatJsonObject
success = jResp.LoadSb(sbResponseBody)
jResp.EmitCompact = 0

Debug.Print "Response Body:"
Debug.Print jResp.Emit()

Dim respStatusCode As Long
respStatusCode = resp.StatusCode
Debug.Print "Response Status Code = " & respStatusCode
If (respStatusCode >= 400) Then
    Debug.Print "Response Header:"
    Debug.Print resp.Header
    Debug.Print "Failed."

    Exit Sub
End If

' Sample JSON response:
' (Sample code for parsing the JSON response is shown below)

' {
'   "access_token": "eyJraWQiOiIxMDEwMTAiLCJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJzdWIiOiIiLCJhdWQiOiJhZGRyZXNzZXMgaW50ZXJuYXRpb25hbC1wcmljZXMgc3Vic2NyaXB0aW9ucyBwYXltZW50cyBwaWNrdXAgdHJhY2tpbmcgbGFiZWxzIHNjYW4tZm9ybXMgY29tcGFuaWVzIHNlcnZpY2UtZGVsaXZlcnktc3RhbmRhcmRzIGxvY2F0aW9ucyBpbnRlcm5hdGlvbmFsLWxhYmVscyBwcmljZXMiLCJhenAiOiJoeXI3YjN2Q1J0cFl0QUhNMWE4Y2RVcmt5eUZtTmtiZyIsIm9yZ2FuaXphdGlvbl9pZCI6IjAiLCJpc3MiOiJ1cm46XC9cL2FwaS51c3BzLmNvbSIsImV4cCI6MTY4MDkxNzc4NiwiaWF0IjoxNjgwODg4OTg2LCJqdGkiOiI3YjU5MzJlMS05NjIxLTQzZDAtYTMyNy0xMzIxYWVjNzJjZGYifQ.QzrUxlT2rG4jvYbMDGnk23j8ZYfHJcdXPKR9CbSmcKeVpURaHhEMpPB6K4x5ut3xxeEGSzeE5VRz8vixI4iqyHsD8rSdkLTPHy0iovUHOZQBAJVQ6hii9jpLhxUXmiTtH3jKzSj_f2fuNmZbIGhf-CR2FBeWF-aBPzEDEMV95nkCUMfW_Z2BmkbraSfvQZxkCO-cLrMAwlYcrzUtaJ7vnazeQB4sep5BBHBEvsa4kfq6_tz6BAKgv3R7cI2NkSv-wgy_IGoTjVCMTS8mJHGs_t8cWCO8-z4lxW1tUwIBKOCUDpmEEnGgiG6Sl0C_gGl4bZ5cDSl4IgPpcOVi9jZ7LA",
'   "token_type": "Bearer",
'   "issued_at": 1680888985929,
'   "expires_in": 28799,
'   "status": "approved",
'   "scope": "addresses international-prices subscriptions payments pickup tracking labels scan-forms companies service-delivery-standards locations international-labels prices",
'   "issuer": "api.usps.com",
'   "client_id": "hyr7b3vCRtpYtAHM1a8cdUrkyyFmNkbg",
'   "application_name": "Silver Shipper Developer",
'   "api_products": "[Shipping-Silver]",
'   "public_key": "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"
' }

' Sample code for parsing the JSON response...
' Use the following online tool to generate parsing code from sample JSON:
' Generate Parsing Code from JSON

Dim access_token As String
access_token = jResp.StringOf("access_token")
Dim token_type As String
token_type = jResp.StringOf("token_type")
Dim issued_at As Long
issued_at = jResp.IntOf("issued_at")
Dim expires_in As Long
expires_in = jResp.IntOf("expires_in")
Dim status As String
status = jResp.StringOf("status")
Dim scope As String
scope = jResp.StringOf("scope")
Dim issuer As String
issuer = jResp.StringOf("issuer")
Dim client_id As String
client_id = jResp.StringOf("client_id")
Dim application_name As String
application_name = jResp.StringOf("application_name")
Dim api_products As String
api_products = jResp.StringOf("api_products")
Dim public_key As String
public_key = jResp.StringOf("public_key")