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Last updated: October 15, 2025

Learn how to embed a pre-built payment user interface in your website to accept payments from your customers. We'll walk you through using the Flow solution, which manages the end-to-end payment experience, including:

Tokenizing sensitive payment details so they never reach your server
Displaying available payment methods
Capturing any additional customer data required
Handling 3D Secure (3DS) authentication and redirection to third-party payment pages

Information

Use the following card details in the interactive demo to perform a test payment:

Cardholder name: Jordan Smith
Card number: 4242 4242 4242 4242
Expiry date: 12/30
Security code: 100

The customer lands on your checkout page.
You perform a server-side request to create a Payment Session.
You use the Payment Session data on the client side to mount Flow.
Flow displays the available payment methods to the customer. If the customer's chosen payment method requires additional customer data, Flow captures this from them.
When the customer selects Pay, Flow performs a payment request and handles any additional actions. For example, additional actions required for 3D Secure (3DS) authentication, or a third-party payment page redirect.
You receive a webhook notifying you of the payment status.

Make sure you have a test account with Checkout.com.

Create a public key and a secret key from the Dashboard, with the following key scopes:

Public key – payment-sessions:pay and vault-tokenization
Secret key – payment-sessions

To receive webhooks for the payment events that may occur throughout the steps, set up your webhook receiver.

When the customer is ready to pay, send a server-side request to securely create a PaymentSession object. The PaymentSession contains the information required to handle all steps of the payment flow.

Call the Request a Payment Session endpoint with your secret key.

Information

Some payment methods may require you to provide additional fields or specific values.

post

https://api.checkout.com/payment-sessions


1{
2  "amount": 1000,
3  "currency": "GBP",
4  "reference": "ORD-123A",
5  "billing": {
6    "address": {
7      "country": "GB"
8    }
9  },
10  "customer": {
11    "name": "Jia Tsang",
12    "email": "[email protected]"
13  },
14  "success_url": "https://example.com/payments/success",
15  "failure_url": "https://example.com/payments/failure"
16}


1{
2  "id": "ps_2Un6I6lRpIAiIEwQIyxWVnV9CqQ",
3  "payment_session_token": "YmFzZTY0:eyJpZCI6InBzXzJVbjZJNmxScElBaUlFd1FJeXhXVm5WOUNxUSIsImFtb3VudCI6MTAwMCwibG9jYWxlIjoiZW4tR0IiLCJjdXJyZW5jeSI6IkdCUCIsInBheW1lbnRfbWV0aG9kcyI6W3sidHlwZSI6ImNhcmQiLCJjYXJkX3NjaGVtZXMiOlsiVmlzYSIsIk1hc3RlcmNhcmQiLCJBbWV4Il19XSwicmlzayI6eyJlbmFibGVkIjp0cnVlfSwiX2xpbmtzIjp7InNlbGYiOnsiaHJlZiI6Imh0dHBzOi8vYXBpLnNhbmRib3guY2hlY2tvdXQuY29tL3BheW1lbnQtc2Vzc2lvbnMvcHNfMlVuNkk2bFJwSUFpSUV3UUl5eFdWblY5Q3FRIn19fQ==",
4  "_links": {
5    "self": {
6      "href": "https://api.sandbox.checkout.com/payment-sessions/ps_2Un6I6lRpIAiIEwQIyxWVnV9CqQ"
7    }
8  }
9}

The response determines which payment methods can be displayed to the customer, depending on the following:

The customer's device
The customer's region
The values you provided for specific fields in your request
The payment methods that are activated for your account

Information

To request to activate additional payment methods on your account, contact your account manager or request support.

You can install the @checkout.com/checkout-web-components package via npm:


1npm install @checkout.com/checkout-web-components --save

Alternatively, you can load the package directly via a script:


1<script src="https://checkout-web-components.checkout.com/index.js" />

Note

To remain PCI compliant, only ever load the script directly from https://checkout-web-components.checkout.com. Do not download or host the script yourself, or include it in a bundle.

Download sample files (.zip)

If you use the template, you must set up your own server.


1<!doctype html>
2<html lang="en">
3    <head>
4        <meta charset="utf-8" />
5        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
6        <title>Checkout Web Components: Flow Component</title>
7        <link rel="stylesheet" href="./style.css" />
8    </head>
9
10    <body>
11        <div id="successToast" class="toast success">
12            <span>The payment was successful</span>
13        </div>
14
15        <div id="failedToast" class="toast failed">
16            <span>The payment failed, try again</span>
17        </div>
18
19        <form>
20            <div class="container">
21                <div id="flow-container"></div>
22            </div>
23            <span id="error-message"></span>
24            <span id="successful-payment-message"></span>
25        </form>
26
27        <script src="https://checkout-web-components.checkout.com/index.js"></script>
28
29        <script src="app.js"></script>
30    </body>
31</html>


1/* Normalize */
2button,hr,input{overflow:visible}progress,sub,sup{vertical-align:baseline}[type=checkbox],[type=radio],legend{box-sizing:border-box;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%}body{margin:0}details,main{display:block}h1{font-size:2em;margin:.67em 0}hr{box-sizing:content-box;height:0}code,kbd,pre,samp{font-family:monospace,monospace;font-size:1em}a{background-color:transparent}abbr[title]{border-bottom:none;text-decoration:underline;text-decoration:underline dotted}b,strong{font-weight:bolder}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}img{border-style:none}button,input,optgroup,select,textarea{font-family:inherit;font-size:100%;line-height:1.15;margin:0}button,select{text-transform:none}[type=button],[type=reset],[type=submit],button{-webkit-appearance:button}[type=button]::-moz-focus-inner,[type=reset]::-moz-focus-inner,[type=submit]::-moz-focus-inner,button::-moz-focus-inner{border-style:none;padding:0}[type=button]:-moz-focusring,[type=reset]:-moz-focusring,[type=submit]:-moz-focusring,button:-moz-focusring{outline:ButtonText dotted 1px}fieldset{padding:.35em .75em .625em}legend{color:inherit;display:table;max-width:100%;white-space:normal}textarea{overflow:auto}[type=number]::-webkit-inner-spin-button,[type=number]::-webkit-outer-spin-button{height:auto}[type=search]{-webkit-appearance:textfield;outline-offset:-2px}[type=search]::-webkit-search-decoration{-webkit-appearance:none}::-webkit-file-upload-button{-webkit-appearance:button;font:inherit}summary{display:list-item}[hidden],template{display:none}
3
4/* Styling */
5*,
6*::before,
7*::after {
8  box-sizing: border-box;
9}
10
11html {
12  padding: 1rem;
13  background-color: #fff;
14  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
15    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
16}
17
18form {
19  max-width: 31.5rem;
20  margin: 0 auto;
21}
22
23.toast {
24  visibility: hidden;
25  min-width: 250px;
26  margin-left: -125px;
27  color: #fff;
28  text-align: center;
29  border-radius: 2px;
30  padding: 16px;
31  position: fixed;
32  z-index: 1;
33  left: 50%;
34  bottom: 0;
35  font-family: monospace;
36  display: inline-flex;
37  line-height: 12px;
38  opacity: 0;
39}
40
41.toast.success {
42  background-color: mediumseagreen;
43}
44
45.toast.failed {
46  background-color: indianred;
47}
48
49.toast span {
50  margin-left: 12px;
51  margin-top: 2px;
52}
53
54.toast.show {
55  visibility: visible;
56  -webkit-animation: fadein 5s;
57  animation: fadein 5s;
58}
59
60@keyframes fadein {
61  0% {
62    bottom: 0;
63    opacity: 0;
64  }
65  16.667% {
66    bottom: 30px;
67    opacity: 1;
68  }
69  83.333% {
70    bottom: 30px;
71    opacity: 1;
72  }
73  100% {
74    bottom: 0;
75    opacity: 0;
76  }
77}


1/* global CheckoutWebComponents */
2(async () => {
3  // Insert your public key here
4  const PUBLIC_KEY = "{your_public_key}";
5
6  const response = await fetch("/create-payment-sessions", { method: "POST" }); // Order
7  const paymentSession = await response.json();
8
9  if (!response.ok) {
10    console.error("Error creating payment session", paymentSession);
11    return;
12  }
13
14  const checkout = await CheckoutWebComponents({
15    publicKey: PUBLIC_KEY,
16    environment: "sandbox",
17    locale: "en-GB",
18    paymentSession,
19    onReady: () => {
20      console.log("onReady");
21    },
22    onPaymentCompleted: (_component, paymentResponse) => {
23      console.log("Create Payment with PaymentId: ", paymentResponse.id);
24    },
25    onChange: (component) => {
26      console.log(
27        `onChange() -> isValid: "${component.isValid()}" for "${
28          component.type
29        }"`,
30      );
31    },
32    onError: (component, error) => {
33      console.log("onError", error, "Component", component.type);
34    },
35  });
36
37  const flowComponent = checkout.create("flow");
38
39  flowComponent.mount(document.getElementById("flow-container"));
40})();
41
42function triggerToast(id) {
43  var element = document.getElementById(id);
44  element.classList.add("show");
45
46  setTimeout(function () {
47    element.classList.remove("show");
48  }, 5000);
49}
50
51const urlParams = new URLSearchParams(window.location.search);
52const paymentStatus = urlParams.get("status");
53const paymentId = urlParams.get("cko-payment-id");
54
55if (paymentStatus === "succeeded") {
56  triggerToast("successToast");
57}
58
59if (paymentStatus === "failed") {
60  triggerToast("failedToast");
61}
62
63if (paymentId) {
64  console.log("Create Payment with PaymentId: ", paymentId);
65}

The client side initializes an instance of CheckoutWebComponents with configuration information and the payment session data returned in the Request a Payment Session response.


1// Insert your public key here
2const publicKey = '{YOUR_PUBLIC_KEY}';
3
4const checkout = await CheckoutWebComponents({
5  paymentSession,
6  publicKey,
7  environment: 'sandbox',
8});

You can use the following configuration options to instantiate an instance of CheckoutWebComponents:

JavaScript key	Description	Required
`publicKey`	Your public API key, prefixed with `pk_`.
`paymentSession`	The response from the `PaymentSession`.
`locale`	Sets the customer's locale. Explicitly providing this value overrides the `locale` returned by the `PaymentSession`. For supported languages, see Localization options.
`environment`	Sets the environment that the library should point to and send requests to. This can be one of: `production` `sandbox`
`translations`	Enables you to provide custom text translations for a natively supported languages, or add custom text for locales and languages not natively supported by Flow. For how to add translations, see Add localization to your Flow integration.
`appearance`	Enables you to customize the visual appearance of the `CheckoutWebComponents` elements. For customization options, see Appearance options.

You can use CheckoutWebComponents to create flow. flow contains a dynamic list of all payment methods available for the payment session you passed into CheckoutWebComponents.


1const flowComponent = checkout.create('flow');

Mount Flow onto your website using the flow.mount() method. The method takes a Selector or an Element as an argument. For example, #flow-container or document.getElementById(#flow-container), respectively.


1flowComponent.mount('#flow-container');


1const flowElement = document.getElementById('flow-container');
2flowComponent.mount(flowElement);

Note

You cannot embed Flow within an iframe or onto a Shadow DOM.

You can use Flow to handle payment methods that require a redirect (asynchronous payments), and those that do not (synchronous payments).

Some payment methods and 3D Secure authentication flows redirect the customer to a success or failure URL on your website, depending on the outcome of the payment.

Checkout.com sends you a webhook notifying you of changes to the payment's status. Wait for the webhook before you initiate your order fulfillment process.

Optionally, you can retrieve the payment result from your server. Call the Get payment details endpoint, and provide the cko-payment-id as the {id} path parameter. For example:


1https://example.com/success?cko-payment-id=pay_mbabizu24mvu3mela5njyhpasd

Payment methods that do not require a redirect raise an onPaymentCompleted event when the payment is successfully completed. You can use this to notify the customer of the payment status.

We send you a webhook notifying you of changes to the payment's status. Wait for the webhook before you initiate your order fulfillment process.


1const checkout = await CheckoutWebComponents({
2  paymentSession,
3  publicKey,
4  onPaymentCompleted: async (_self, paymentResponse) => {
5    // Handle synchronous payments
6    await handlePayment(paymentResponse.id);
7  },
8});

Optionally, you can retrieve the payment result from your server, with a Get payment details requet.

Use test cards to simulate different payment flows and ensure your integration is set up correctly and behaving as expected.

You can check the payment's status on the Payments page in the Dashboard.

Get started

Information

How it works

Before you begin

Create a new Payment Session
Server side

Information

Request example

Response example

Information

Initialize and mount Flow
Client side

Note

Download project template (optional)

Configuration options

Note

Handle the payment response
Client side

Asynchronous payments

Synchronous payments

Test the integration

Next steps

Customize your Flow integration

Add localization to your Flow integration

Use 3D Secure to authenticate your payments

Store payment details for faster checkout

Information

How it works

Before you begin

Create a new Payment Session Server side

Information

Request example

Response example

Information

Initialize and mount Flow Client side

Note

Download project template (optional)

Configuration options

Note

Handle the payment response Client side

Asynchronous payments

Synchronous payments

Test the integration

Next steps

Customize your Flow integration

Add localization to your Flow integration

Use 3D Secure to authenticate your payments

Store payment details for faster checkout

Create a new Payment Session
Server side

Initialize and mount Flow
Client side

Handle the payment response
Client side