(Delphi ActiveX) Amazon Pay - Create Checkout Session

See more Amazon Pay Examples

Create a new Amazon Pay Checkout Session.

Note: This example requires Chilkat v9.5.0.89 or later. Contact support@chilkatsoft.com to get a v9.5.0.89 pre-release for testing.

For more information, see https://developer.amazon.com/docs/amazon-pay-api-v2/checkout-session.html#create-checkout-session

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

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
http: TChilkatHttp;
success: Integer;
json: TChilkatJsonObject;
i: Integer;
privKey: TPrivateKey;
publicKeyId: WideString;
resp: IChilkatHttpResponse;
sbResponseBody: TChilkatStringBuilder;
jResp: TChilkatJsonObject;
respStatusCode: Integer;
nullVal: Integer;
constraintId: WideString;
description: WideString;
strVal: WideString;
checkoutSessionId: WideString;
webCheckoutDetailsCheckoutReviewReturnUrl: WideString;
webCheckoutDetailsCheckoutResultReturnUrl: WideString;
webCheckoutDetailsCheckoutCancelUrl: WideString;
webCheckoutDetailsAmazonPayRedirectUrl: WideString;
productType: WideString;
chargePermissionType: WideString;
recurringMetadataFrequencyUnit: WideString;
recurringMetadataFrequencyValue: WideString;
recurringMetadataAmountAmount: WideString;
recurringMetadataAmountCurrencyCode: WideString;
paymentDetailsPaymentIntent: WideString;
paymentDetailsCanHandlePendingAuthorization: Integer;
paymentDetailsChargeAmount: WideString;
paymentDetailsTotalOrderAmount: WideString;
paymentDetailsSoftDescriptor: WideString;
paymentDetailsPresentmentCurrency: WideString;
paymentDetailsAllowOvercharge: WideString;
paymentDetailsExtendExpiration: WideString;
merchantMetadataMerchantReferenceId: WideString;
merchantMetadataMerchantStoreName: WideString;
merchantMetadataNoteToBuyer: WideString;
merchantMetadataCustomInformation: WideString;
supplementaryData: WideString;
buyer: WideString;
billingAddress: WideString;
statusDetailsState: WideString;
statusDetailsReasonCode: WideString;
statusDetailsReasonDescription: WideString;
statusDetailsLastUpdatedTimestamp: WideString;
shippingAddress: WideString;
platformId: WideString;
chargePermissionId: WideString;
chargeId: WideString;
creationTimestamp: WideString;
expirationTimestamp: WideString;
storeId: WideString;
deliverySpecificationsAddressRestrictionsType: WideString;
providerMetadataProviderReferenceId: WideString;
releaseEnvironment: WideString;
count_i: Integer;

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

http := TChilkatHttp.Create(Self);

// Implements the following CURL command:

// curl "https://pay-api.amazon.com/:version/checkoutSessions/" \
// -X POST
// -H "authorization:Px2e5oHhQZ88vVhc0DO%2FsShHj8MDDg%3DEXAMPLESIGNATURE"
// -H "x-amz-pay-date:20201012T235046Z"
// -H "x-amz-pay-idempotency-key:AVLo5tI10BHgEk2jEXAMPLEKEY"
// -d '{
//     "webCheckoutDetails": {
//         "checkoutReviewReturnUrl": "https://a.com/merchant-review-page"
//     },
//     "storeId": "amzn1.application-oa2-client.8b5e45312b5248b69eeaStoreId",
//     "scopes": ["name", "email", "phoneNumber", "billingAddress"],
//     "deliverySpecifications": {
//         "specialRestrictions": ["RestrictPOBoxes"],
//         "addressRestrictions": {
//             "type": "Allowed",
//             "restrictions": {
//                 "US": {
//                     "statesOrRegions": ["WA"],
//                     "zipCodes": ["95050", "93405"]
//                 },
//                 "GB": {
//                     "zipCodes": ["72046", "72047"]
//                 },
//                 "IN": {
//                     "statesOrRegions": ["AP"]
//                 },
//                 "JP": {}
//             }
//         }
//     }
// }'

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

// Use this online tool to generate code from sample JSON:
// Generate Code to Create JSON

// The following JSON is sent in the request body.

// {
//   "webCheckoutDetails": {
//     "checkoutReviewReturnUrl": "https://a.com/merchant-review-page"
//   },
//   "storeId": "amzn1.application-oa2-client.8b5e45312b5248b69eeaStoreId",
//   "scopes": [
//     "name",
//     "email",
//     "phoneNumber",
//     "billingAddress"
//   ],
//   "deliverySpecifications": {
//     "specialRestrictions": [
//       "RestrictPOBoxes"
//     ],
//     "addressRestrictions": {
//       "type": "Allowed",
//       "restrictions": {
//         "US": {
//           "statesOrRegions": [
//             "WA"
//           ],
//           "zipCodes": [
//             "95050",
//             "93405"
//           ]
//         },
//         "GB": {
//           "zipCodes": [
//             "72046",
//             "72047"
//           ]
//         },
//         "IN": {
//           "statesOrRegions": [
//             "AP"
//           ]
//         },
//         "JP": {}
//       }
//     }
//   }
// }

json := TChilkatJsonObject.Create(Self);
json.UpdateString('webCheckoutDetails.checkoutReviewReturnUrl','https://a.com/merchant-review-page');
// Make sure to use your storeId here:
json.UpdateString('storeId','amzn1.application-oa2-client.8b5e45312b5248b69eeaStoreId');
i := 0;
json.I := i;
json.UpdateString('scopes[i]','name');
i := i + 1;
json.I := i;
json.UpdateString('scopes[i]','email');
i := i + 1;
json.I := i;
json.UpdateString('scopes[i]','phoneNumber');
i := i + 1;
json.I := i;
json.UpdateString('scopes[i]','billingAddress');
json.UpdateString('deliverySpecifications.specialRestrictions[0]','RestrictPOBoxes');
json.UpdateString('deliverySpecifications.addressRestrictions.type','Allowed');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions[0]','WA');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[0]','95050');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[1]','93405');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[0]','72046');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[1]','72047');
json.UpdateString('deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions[0]','AP');
json.UpdateNewObject('deliverySpecifications.addressRestrictions.restrictions.JP');

// Load your Amazon Pay private key.  
// There are many other ways to load private keys into the Chilkat private key object, such as from different formats,
// or from in-memory strings or bytes.
privKey := TPrivateKey.Create(Self);
success := privKey.LoadPemFile('C:/someDir/myAmazonPayPrivateKey.pem');
if (success = 0) then
  begin
    Memo1.Lines.Add(privKey.LastErrorText);
    Exit;
  end;

// Provide your Amazon Pay private key and Public Key ID 
// Use your public key ID here.  It must be the one associated with the private key.
// Note: The SetAuthPrivateKey method was added in Chilkat v9.5.0.89
publicKeyId := 'SANDBOX-AHEGSJCM3L2S637RBGABLAFW';
success := http.SetAuthPrivateKey(publicKeyId,privKey.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

// Note: When the private key is provided as shown above, Chilkat will automatically add the required x-amz-pay-* headers to the HTTP request,
// and will also sign the request.  Nothing more is needed.
// Chilkat automatically generates and adds the following headers:
// 
// x-amz-pay-date
// x-amz-pay-host
// x-amz-pay-region
// x-amz-pay-idempotency-key
// Authorization

http.Accept := 'application/json';

// To use the live system, replace "sandbox" with "live" in the URL passed to PostJson3.
// Also, make sure to use the correct region: pay-api.amazon.com, pay-api.amazon.eu, or pay-api.amazon.jp
resp := http.PostJson3('https://pay-api.amazon.eu/sandbox/v2/checkoutSessions/','application/json',json.ControlInterface);
if (http.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

sbResponseBody := TChilkatStringBuilder.Create(Self);
resp.GetBodySb(sbResponseBody.ControlInterface);
jResp := TChilkatJsonObject.Create(Self);
jResp.LoadSb(sbResponseBody.ControlInterface);
jResp.EmitCompact := 0;

// If the status code is not equal to 201, this will display error information.
Memo1.Lines.Add('Response Body:');
Memo1.Lines.Add(jResp.Emit());

respStatusCode := resp.StatusCode;
Memo1.Lines.Add('Response Status Code = ' + IntToStr(respStatusCode));
if (respStatusCode <> 201) then
  begin

    // The jResp would've contained an error message, similar to this:
    // 	{
    // 	  "reasonCode": "InvalidHeaderValue",
    // 	  "message": "The value AF2EGWREIPHV2S2TUFFBRDGM provided for PublicKeyId is invalid. Please verify that you are using the PublicKeyId in the correct region and environment."
    // 	}

    Memo1.Lines.Add('Failed.');

    Exit;
  end;

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

// {
//   "checkoutSessionId": "bd504926-f659-4ad7-a1a9-9a747aaf5275",
//   "webCheckoutDetails": {
//     "checkoutReviewReturnUrl": "https://a.com/merchant-review-page",
//     "checkoutResultReturnUrl": null,
//     "checkoutCancelUrl": null,
//     "amazonPayRedirectUrl": null
//   },
//   "productType": "PayAndShip",
//   "chargePermissionType": "Recurring",
//   "recurringMetadata": {
//     "frequency": {
//       "unit": "Month",
//       "value": "1"
//     },
//     "amount": {
//       "amount": "30",
//       "currencyCode": "USD"
//     }
//   },
//   "paymentDetails": {
//     "paymentIntent": null,
//     "canHandlePendingAuthorization": false,
//     "chargeAmount": null,
//     "totalOrderAmount": null,
//     "softDescriptor": null,
//     "presentmentCurrency": null,
//     "allowOvercharge": null,
//     "extendExpiration": null
//   },
//   "merchantMetadata": {
//     "merchantReferenceId": null,
//     "merchantStoreName": null,
//     "noteToBuyer": null,
//     "customInformation": null
//   },
//   "supplementaryData": null,
//   "buyer": null,
//   "billingAddress": null,
//   "paymentPreferences": [
//     null
//   ],
//   "statusDetails": {
//     "state": "Open",
//     "reasonCode": null,
//     "reasonDescription": null,
//     "lastUpdatedTimestamp": "20191015T204327Z"
//   },
//   "shippingAddress": null,
//   "platformId": null,
//   "chargePermissionId": null,
//   "chargeId": null,
//   "constraints": [
//     {
//       "constraintId": "BuyerNotAssociated",
//       "description": "There is no buyer associated with the Checkout Session. Return the checkout session id to the Amazon Pay Button to allow buyer to login."
//     },
//     {
//       "constraintId": "ChargeAmountNotSet",
//       "description": "chargeAmount is not set."
//     },
//     {
//       "constraintId": "CheckoutResultReturnUrlNotSet",
//       "description": "checkoutResultReturnUrl is not set."
//     },
//     {
//       "constraintId": "PaymentIntentNotSet",
//       "description": "paymentIntent is not set."
//     }
//   ],
//   "creationTimestamp": "20191015T204313Z",
//   "expirationTimestamp": "20191016T204313Z",
//   "storeId": "amzn1.application-oa2-client.8b5e45312b5248b69eeaStoreId",
//   "deliverySpecifications": {
//     "specialRestrictions": [
//       "RestrictPOBoxes"
//     ],
//     "addressRestrictions": {
//       "type": "Allowed",
//       "restrictions": {
//         "US": {
//           "statesOrRegions": [
//             "WA"
//           ],
//           "zipCodes": [
//             "95050",
//             "93405"
//           ]
//         },
//         "GB": {
//           "zipCodes": [
//             "72046",
//             "72047"
//           ]
//         },
//         "IN": {
//           "statesOrRegions": [
//             "AP"
//           ]
//         },
//         "JP": {}
//       }
//     }
//   },
//   "providerMetadata": {
//     "providerReferenceId": null
//   },
//   "releaseEnvironment": "Sandbox"
// }

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

checkoutSessionId := jResp.StringOf('checkoutSessionId');
webCheckoutDetailsCheckoutReviewReturnUrl := jResp.StringOf('webCheckoutDetails.checkoutReviewReturnUrl');
webCheckoutDetailsCheckoutResultReturnUrl := jResp.StringOf('webCheckoutDetails.checkoutResultReturnUrl');
webCheckoutDetailsCheckoutCancelUrl := jResp.StringOf('webCheckoutDetails.checkoutCancelUrl');
webCheckoutDetailsAmazonPayRedirectUrl := jResp.StringOf('webCheckoutDetails.amazonPayRedirectUrl');
productType := jResp.StringOf('productType');
chargePermissionType := jResp.StringOf('chargePermissionType');
recurringMetadataFrequencyUnit := jResp.StringOf('recurringMetadata.frequency.unit');
recurringMetadataFrequencyValue := jResp.StringOf('recurringMetadata.frequency.value');
recurringMetadataAmountAmount := jResp.StringOf('recurringMetadata.amount.amount');
recurringMetadataAmountCurrencyCode := jResp.StringOf('recurringMetadata.amount.currencyCode');
paymentDetailsPaymentIntent := jResp.StringOf('paymentDetails.paymentIntent');
paymentDetailsCanHandlePendingAuthorization := jResp.BoolOf('paymentDetails.canHandlePendingAuthorization');
paymentDetailsChargeAmount := jResp.StringOf('paymentDetails.chargeAmount');
paymentDetailsTotalOrderAmount := jResp.StringOf('paymentDetails.totalOrderAmount');
paymentDetailsSoftDescriptor := jResp.StringOf('paymentDetails.softDescriptor');
paymentDetailsPresentmentCurrency := jResp.StringOf('paymentDetails.presentmentCurrency');
paymentDetailsAllowOvercharge := jResp.StringOf('paymentDetails.allowOvercharge');
paymentDetailsExtendExpiration := jResp.StringOf('paymentDetails.extendExpiration');
merchantMetadataMerchantReferenceId := jResp.StringOf('merchantMetadata.merchantReferenceId');
merchantMetadataMerchantStoreName := jResp.StringOf('merchantMetadata.merchantStoreName');
merchantMetadataNoteToBuyer := jResp.StringOf('merchantMetadata.noteToBuyer');
merchantMetadataCustomInformation := jResp.StringOf('merchantMetadata.customInformation');
supplementaryData := jResp.StringOf('supplementaryData');
buyer := jResp.StringOf('buyer');
billingAddress := jResp.StringOf('billingAddress');
statusDetailsState := jResp.StringOf('statusDetails.state');
statusDetailsReasonCode := jResp.StringOf('statusDetails.reasonCode');
statusDetailsReasonDescription := jResp.StringOf('statusDetails.reasonDescription');
statusDetailsLastUpdatedTimestamp := jResp.StringOf('statusDetails.lastUpdatedTimestamp');
shippingAddress := jResp.StringOf('shippingAddress');
platformId := jResp.StringOf('platformId');
chargePermissionId := jResp.StringOf('chargePermissionId');
chargeId := jResp.StringOf('chargeId');
creationTimestamp := jResp.StringOf('creationTimestamp');
expirationTimestamp := jResp.StringOf('expirationTimestamp');
storeId := jResp.StringOf('storeId');
deliverySpecificationsAddressRestrictionsType := jResp.StringOf('deliverySpecifications.addressRestrictions.type');
providerMetadataProviderReferenceId := jResp.StringOf('providerMetadata.providerReferenceId');
releaseEnvironment := jResp.StringOf('releaseEnvironment');
i := 0;
count_i := jResp.SizeOfArray('paymentPreferences');
while i < count_i do
  begin
    jResp.I := i;
    nullVal := jResp.IsNullOf('paymentPreferences[i]');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('constraints');
while i < count_i do
  begin
    jResp.I := i;
    constraintId := jResp.StringOf('constraints[i].constraintId');
    description := jResp.StringOf('constraints[i].description');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('deliverySpecifications.specialRestrictions');
while i < count_i do
  begin
    jResp.I := i;
    strVal := jResp.StringOf('deliverySpecifications.specialRestrictions[i]');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions');
while i < count_i do
  begin
    jResp.I := i;
    strVal := jResp.StringOf('deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions[i]');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('deliverySpecifications.addressRestrictions.restrictions.US.zipCodes');
while i < count_i do
  begin
    jResp.I := i;
    strVal := jResp.StringOf('deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[i]');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes');
while i < count_i do
  begin
    jResp.I := i;
    strVal := jResp.StringOf('deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[i]');
    i := i + 1;
  end;

i := 0;
count_i := jResp.SizeOfArray('deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions');
while i < count_i do
  begin
    jResp.I := i;
    strVal := jResp.StringOf('deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions[i]');
    i := i + 1;
  end;
end;