Pascal (Lazarus/Delphi)

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) Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Http,
  Chilkat.HttpRequest,
  Chilkat.HttpResponse,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  req: THttpRequest;
  resp: THttpResponse;
  statusCode: Integer;
  json: TJsonObject;

begin
  success := False;

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

  http := THttp.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 := THttpRequest.Create;
  req.AddParam('grant_type','refresh_token');
  req.AddParam('refresh_token','Aztr|...');
  req.AddParam('client_id','foodev');
  req.AddParam('client_secret','Y76SDl2F');

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

  req.HttpVerb := 'POST';
  req.ContentType := 'application/x-www-form-urlencoded';

  resp := THttpResponse.Create;
  success := http.HttpReq('https://api.amazon.com/auth/o2/token',req,resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  statusCode := resp.StatusCode;
  WriteLn('Status Code = ' + statusCode);

  json := TJsonObject.Create;
  json.Load(resp.BodyStr);

  json.EmitCompact := False;
  WriteLn(json.Emit());

  if (statusCode <> 200) then
    begin
      WriteLn('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 := json.WriteFile('qa_data/tokens/sp_api_lwa_token.json');

  WriteLn('access_token: ' + json.StringOf('access_token'));
  WriteLn('Success.');


  http.Free;
  req.Free;
  resp.Free;
  json.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.