(Delphi DLL) Amazon SP-API Request an LWA access token

See more Amazon SP-API Examples

Request an LWA access token, make a secure HTTP POST to the LWA authentication server (https://api.amazon.com/auth/o2/token)

For more information, see https://developer-docs.amazon.com/sp-api/docs/connecting-to-the-selling-partner-api

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Http, HttpRequest, HttpResponse, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: HCkHttp;
req: HCkHttpRequest;
resp: HCkHttpResponse;
statusCode: Integer;
json: HCkJsonObject;
success: Boolean;

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

http := CkHttp_Create();

// Implements the following CURL command:

// curl -X POST https://example.com/auth/o2/token \
//   -H "Host: api.amazon.com" \
//   -H "Content-Type: application/x-www-form-urlencoded;charset=UTF-8" \
//   -d "grant_type=refresh_token" \
//   -d "refresh_token=Aztr|..." \
//   -d "client_id=foodev" \
//   -d "client_secret=Y76SDl2F"

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

req := CkHttpRequest_Create();
CkHttpRequest_AddParam(req,'grant_type','refresh_token');
CkHttpRequest_AddParam(req,'refresh_token','Aztr|...');
CkHttpRequest_AddParam(req,'client_id','foodev');
CkHttpRequest_AddParam(req,'client_secret','Y76SDl2F');

CkHttpRequest_AddHeader(req,'Host','api.amazon.com');

resp := CkHttp_PostUrlEncoded(http,'https://api.amazon.com/auth/o2/token',req);
if (CkHttp_getLastMethodSuccess(http) = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

statusCode := CkHttpResponse_getStatusCode(resp);
Memo1.Lines.Add('Status Code = ' + IntToStr(statusCode));

json := CkJsonObject_Create();
CkJsonObject_Load(json,CkHttpResponse__bodyStr(resp));
CkHttpResponse_Dispose(resp);

CkJsonObject_putEmitCompact(json,False);
Memo1.Lines.Add(CkJsonObject__emit(json));

if (statusCode <> 200) then
  begin
    Memo1.Lines.Add('Failed.');
    Exit;
  end;

// Success returns this JSON:

// {
//   "access_token": "Atza|...",
//   "refresh_token": "Atzr|...",
//   "token_type": "bearer",
//   "expires_in": 3600
// }

// Save the JSON token to a file for use in subsequent calls.
// (this example is passing a relative file path.  You don't need to save to a file
// if, for example, you keep the access token in-memory for subsequent use...)
success := CkJsonObject_WriteFile(json,'qa_data/tokens/sp_api_lwa_token.json');

Memo1.Lines.Add('access_token: ' + CkJsonObject__stringOf(json,'access_token'));
Memo1.Lines.Add('Success.');

CkHttp_Dispose(http);
CkHttpRequest_Dispose(req);
CkJsonObject_Dispose(json);

end;