(Delphi DLL) 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 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, StringBuilder, PrivateKey, HttpResponse, JsonObject;

...

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

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 "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 := CkJsonObject_Create();
CkJsonObject_UpdateString(json,'webCheckoutDetails.checkoutReviewReturnUrl','https://a.com/merchant-review-page');
// Make sure to use your storeId here:
CkJsonObject_UpdateString(json,'storeId','amzn1.application-oa2-client.8b5e45312b5248b69eeaStoreId');
i := 0;
CkJsonObject_putI(json,i);
CkJsonObject_UpdateString(json,'scopes[i]','name');
i := i + 1;
CkJsonObject_putI(json,i);
CkJsonObject_UpdateString(json,'scopes[i]','email');
i := i + 1;
CkJsonObject_putI(json,i);
CkJsonObject_UpdateString(json,'scopes[i]','phoneNumber');
i := i + 1;
CkJsonObject_putI(json,i);
CkJsonObject_UpdateString(json,'scopes[i]','billingAddress');
CkJsonObject_UpdateString(json,'deliverySpecifications.specialRestrictions[0]','RestrictPOBoxes');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.type','Allowed');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions[0]','WA');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[0]','95050');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[1]','93405');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[0]','72046');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[1]','72047');
CkJsonObject_UpdateString(json,'deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions[0]','AP');
CkJsonObject_UpdateNewObject(json,'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 := CkPrivateKey_Create();
success := CkPrivateKey_LoadPemFile(privKey,'C:/someDir/myAmazonPayPrivateKey.pem');
if (success = False) then
  begin
    Memo1.Lines.Add(CkPrivateKey__lastErrorText(privKey));
    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 := CkHttp_SetAuthPrivateKey(http,publicKeyId,privKey);
if (success = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    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

CkHttp_putAccept(http,'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 := CkHttp_PostJson3(http,'https://pay-api.amazon.eu/sandbox/v2/checkoutSessions/','application/json',json);
if (CkHttp_getLastMethodSuccess(http) = False) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

sbResponseBody := CkStringBuilder_Create();
CkHttpResponse_GetBodySb(resp,sbResponseBody);
jResp := CkJsonObject_Create();
CkJsonObject_LoadSb(jResp,sbResponseBody);
CkJsonObject_putEmitCompact(jResp,False);

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

respStatusCode := CkHttpResponse_getStatusCode(resp);
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.');
    CkHttpResponse_Dispose(resp);
    Exit;
  end;
CkHttpResponse_Dispose(resp);

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

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'constraints');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    constraintId := CkJsonObject__stringOf(jResp,'constraints[i].constraintId');
    description := CkJsonObject__stringOf(jResp,'constraints[i].description');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'deliverySpecifications.specialRestrictions');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    strVal := CkJsonObject__stringOf(jResp,'deliverySpecifications.specialRestrictions[i]');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    strVal := CkJsonObject__stringOf(jResp,'deliverySpecifications.addressRestrictions.restrictions.US.statesOrRegions[i]');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'deliverySpecifications.addressRestrictions.restrictions.US.zipCodes');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    strVal := CkJsonObject__stringOf(jResp,'deliverySpecifications.addressRestrictions.restrictions.US.zipCodes[i]');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    strVal := CkJsonObject__stringOf(jResp,'deliverySpecifications.addressRestrictions.restrictions.GB.zipCodes[i]');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(jResp,'deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions');
while i < count_i do
  begin
    CkJsonObject_putI(jResp,i);
    strVal := CkJsonObject__stringOf(jResp,'deliverySpecifications.addressRestrictions.restrictions.IN.statesOrRegions[i]');
    i := i + 1;
  end;

CkHttp_Dispose(http);
CkJsonObject_Dispose(json);
CkPrivateKey_Dispose(privKey);
CkStringBuilder_Dispose(sbResponseBody);
CkJsonObject_Dispose(jResp);

end;