Primer Docs

Where there is a need for more customization and control over the checkout experience, a headless version of Primer’s Universal Checkout is available.

You can use Headless Universal Checkout with your UI, giving you more flexibility and allowing you to move faster when making design changes, while still having Universal Checkout capture sensitive PCI card data or other form data.

If you're looking for a simpler way of integrating Universal Checkout, consider integrating our Drop-In checkout.

Not all payment methods are currently compatible with Headless Checkout.

Please refer to this table to learn more about the payment methods available for Headless Checkout.

Before you start

Before you start, make sure:

you are ready to process a payment
Universal Checkout is properly configured in the dashboard

Create a client session

A client session is the starting point for integrating payments at Primer. You can attach any data associated with the order to your client session.

Creating a client session provides you with a client token, a temporary key used to initialize the Universal Checkout.

The information you include in the client session is used in the Dashboard:

to conditionally route payments with Workflows
to activate payment methods and other features in Universal Checkout

So pass as much information as you can!

Generate an API key

Requests to our API are authenticated using an API key in the X-Api-Key header. Create an API key by visiting the developer page of the Primer Dashboard.

Make sure to set the following scopes for your API Key:

client_tokens:write
transactions:authorize

Make a client session request

On your server, create a client session with POST/client-session.

Make sure to pass at least the following data:

Field	Description
orderId	Your reference for the payment. Make sure to keep track of `orderId` - you will later receive updates to the payment via Webhooks. The payment will contain the `orderId` specified in the client session.
currencyCode	The three-letter currency code in ISO 4217 format. e.g. use `USD` for US dollars.
order ↳ lineItems	The details of the line items of the order.

ℹ️

The body of a successful response contains a clientToken that you will use to initialize the Universal Checkout.

Here is how the client session request to the Primer API should look like:

123456789101112131415161718192021222324252627282930313233343536curl --location --request \ POST 'https://api.sandbox.primer.io/client-session' \ --header 'X-Api-Key: <YOUR_API_KEY>' \ --header 'X-Api-Version: 2.2' \ --header 'Content-Type: application/json' --data '{    "orderId": "<YOUR_ORDER_ID>",    "currencyCode": "GBP",    "amount": 5000,    "order": {      "lineItems": [{        "itemId": "shoes-123",        "amount": 2500,        "quantity": 2      }],      "countryCode": "GB",    } }'
# Here is a (heavily truncated) example response
{  "clientToken": "THE_CHECKOUT_SESSION_TOKEN",  "clientExpirationDate": "2022-03-08T14:00:00Z",  "orderId": "<YOUR_ORDER_ID>",  "currencyCode": "GBP",  "amount": 5000,    "order": {    "lineItems": [{      "itemId": "shoes-123",      "amount": 2500,      "quantity": 2    }],    "countryCode": "GB",  }}

bash

copy

To use new Workflows and all of its exciting features, make sure to pass the following header in your API request:

1Legacy-Workflows: false

shell

copy

See this migration guide for more information.

Get Started

Primer Headless Universal Checkout works in a simple way:

1
Get a clientToken from your server.
2
Start Primer Headless Universal Checkout with the client token.
3
Primer Headless Universal Checkout will then return the available payment methods for the session initiated. Those payment methods that have been configured in the Dashboard and whose conditions match the current client session will be returned.
4
You show the user the list of available payment methods.
5
When the user selects a payment method, show its UI to enable the user to enter their credentials. Depending on the payment method, you will have to either ask the SDK to render it, or build the UI yourself.
6
Primer's Headless Universal Checkout will then create a payment for you and manage its lifecycle. You will receive a confirmation of payment with a callback to indicate the checkout flow has completed.

Web iOS Android React Native

This documentation is only relevant for v2.21.0 and upward.

Step 1. Install the SDK

With npm

Our Web SDK is available on npm under the name @primer-io/checkout-web.

This package includes TypeScript definitions.

12345# With yarnyarn add @primer-io/checkout-web
# With npmnpm install --save @primer-io/checkout-web

bash

copy

123import { Primer } from '@primer-io/checkout-web'
Primer.createHeadless(clientToken)

typescript

copy

The npm package only works if used alongside a bundler such as Webpack or Parcel. If you're directly writing JavaScript using script tag, please use our CDN instead.
As of today, the npm package does not work in a server environment. If you are using Next.js, Gatsby, or a similar framework, make sure the Primer functions are called on the client side, or use our CDN instead.

With our CDN

Include the Primer.min.js script and the Checkout.css stylesheet on the page where you want to render the Checkout. Make sure to pass the proper version in the URL.

12<link rel="stylesheet" href="https://sdk.primer.io/web/v2.35.1/Checkout.css" /><script src="https://sdk.primer.io/web/v2.35.1/Primer.min.js" crossorigin="anonymous"></script>

html

copy

The Primer.min.js will add the Primer object to the global scope:

123const { Primer } = window
Primer.createHeadless(clientToken)

typescript

copy

Step 2: Initialize Primer’s Headless Universal Checkout

Generate a client token

Request a client token from your backend by creating a client session.

💡

Check our guide on how to create a client session here.

❗️

Remember that based on your client token different payment methods will be available for display.

Configure Headless Universal Checkout

Once you have a client token, initialize Primer’s headless checkout with Primer.createHeadless(clientToken).

1const headless = await Primer.createHeadless(clientToken)

typescript

copy

Then, configure headless checkout by calling headless.configure(options). Make sure to implement at least the following callbacks:

onAvailablePaymentMethodsLoad(paymentMethodTypes)
returns the available payment methods for the client session. Use it to render a list of payment methods.
onCheckoutComplete(data)
is called when the payment has been successfully completed. It returns a reference to the payment.
onCheckoutFail(error, data, handler)
is called if the payment fails to be created or processed.

Payment methods are added and configured through your Primer Dashboard. onAvailablePaymentMethodsLoad will return the payment methods whose conditions match the current client session.

Finally, call headless.start() to retrieve the list of payment methods, and start the checkout flow.

1await headless.start()

typescript

copy

Here is a full example to configure and start Headless Universal Checkout:

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475window.addEventListener('load', onLoaded)
async function onLoaded() {    // Create a client session via your backend    const clientSession = await fetch('/client-session', {        method: 'post',        headers: { 'Content-Type': 'application/json' },    }).then(data => data.json())
    const { clientToken } = clientSession    const { Primer } = window
    // Create an instance of the headless checkout    const headless = await Primer.createHeadless(clientToken)
    // Configure headless    await headless.configure({        onAvailablePaymentMethodsLoad(paymentMethods) {            // Called when the available payment methods are retrieved
            for (const paymentMethod of paymentMethods) {                // `type` is a unique ID representing the payment method                const { type, managerType } = paymentMethod
                switch (managerType) {                    case 'CARD': {                        // Configure your card form (see Step 4.a)                        // await configureCardForm(paymentMethod);                        break                    }                    case 'NATIVE': {                        // Render the native payment method button (see Step 4.b)                        // Relevant for PayPal, Apple Pay and Google Pay                        // configureNativeButton(paymentMethod);                        break                    }                    case 'REDIRECT': {                        // Handle redirect payment methods (see Step 4.c)                        // configureRedirectPaymentMethod(paymentMethod);                        break                    }
                    // More payment methods to follow                }            }        },
        onCheckoutComplete({ payment }) {            // Notifies you that a payment was created            // Move on to next step in your checkout flow:            // e.g. Show a success message, giving access to the service, fulfilling the order, ...            console.log('onCheckoutComplete', payment)        },
        onCheckoutFail(error, { payment }, handler) {            // Notifies you that the checkout flow has failed and a payment could not be created            // This callback can also be used to display an error state within your own UI.
            // ⚠️ `handler` is undefined if the SDK does not expect anything from you            if (!handler) {                return            }
            // ⚠️ If `handler` exists, you MUST call one of the functions of the handler
            // Show a default error message            return handler.showErrorMessage()        },    })
    // Start the headless checkout    await headless.start()
    console.log('Headless Universal Checkout is loaded!')}

typescript

copy

See more options and events in the SDK API Reference

Step 3: Show available payment methods

When the checkout is done initializing, the callback onAvailablePaymentMethodsLoad is invoked. Use this event to show the list of payment methods to the user:

Some payment methods such as Google Pay, Apple Pay, and PayPal require Primer to manage their payment method button.
For the others, you have full control over how the payment method button should be presented. To assist you, Primer exposes the AssetsManager that enables you to retrieve the logo and main colors attached to each payment method.

1234// getAssetsManager() is only available once Headless Checkout has been fully initializedconst assetsManager = headless.getAssetsManager()
const { iconUrl, paymentMethodName, backgroundColor } = await assetsManager.getPaymentMethodAsset('ADYEN_IDEAL') // ADYEN_IDEAL comes from `paymentMethod.type`

typescript

copy

The assets manager is only available once onAvailablePaymentMethodsLoad has been called.

Step 4: Handle payment method selection

Headless Universal Checkout enables you to create any UI that suits your needs, using the components and data we provide.

Step 4.a: Handle cards

When PAYMENT_CARD is available as a payment method and provided via onAvailablePaymentMethodsLoad, build your card form using Primer input elements.

Get started by creating a payment method manager for cards.

1const cardManager = await headless.createPaymentMethodManager('PAYMENT_CARD')

typescript

copy

Show card fields

Headless Universal Checkout securely captures payment method data while fully embedded in your app. By communicating directly with Primer's PCI-L1 tokenization service, Universal Checkout transforms sensitive customer data into a secure uniform string called a payment method token.

First, prepare containers in the DOM for the Primer hosted inputs. You would need three containers for the card number, the expiry date, and the CVV.

123456789101112131415const container = document.getElementById('my-container')
const cardNumberInputId = 'checkout-card-number-input'const cardNumberInputEl = document.createElement('div')cardNumberInputEl.setAttribute('id', cardNumberInputId)
const cardExpiryInputId = 'checkout-card-expiry-input'const cardExpiryInputEl = document.createElement('div')cardExpiryInputEl.setAttribute('id', cardExpiryInputId)
const cardCvvInputId = 'checkout-card-cvv-input'const cardCvvInputEl = document.createElement('div')cardCvvInputEl.setAttribute('id', cardCvvInputId)
container.append(cardNumberInputEl, cardExpiryInputEl, cardCvvInputEl)

typescript

copy

Then, create the hosted card inputs:

1const { cardNumberInput, expiryInput, cvvInput } = cardManager.createHostedInputs()

typescript

copy

Finally, render your inputs into the relevant containers:

1234567891011121314await Promise.all([    cardNumberInput.render(cardNumberInputId, {        placeholder: '1234 1234 1234 1234',        ariaLabel: 'Card number',    }),    expiryInput.render(cardExpiryInputId, {        placeholder: 'MM/YY',        ariaLabel: 'Expiry date',    }),    cvvInput.render(cardCvvInputId, {        placeholder: '123',        ariaLabel: 'CVV',    }),])

typescript

copy

Customize card fields

Card fields are rendered with individual iframes in order to remain PCI-L1 compliant. One key consequence is that the CSS of your page will not be propagated to the card fields. This includes color, and font.

Pass a style object to the render function to configure colors and font options.

1234567891011121314151617const style = {    input: {        base: {            height: 'auto',            border: '1px solid rgb(0 0 0 / 10%)',            borderRadius: '2px',            padding: '12px',            boxShadow: '0 4px 8px 0 rgba(0,0,0,0.2)',        },    },}
cardNumberInput.render(cardNumberInputId, {    placeholder: '1234 1234 1234 1234',    ariaLabel: 'Card number',    style,})

typescript

copy

Check the "Styling Inputs" section of the Customize Universal Checkout guide to learn how to adapt the style to your requirements.

Reset card form

If needed, the card form can be cleared by calling reset():

1cardManager.reset()

typescript

copy

Remove card elements

Call removeHostedInputs() to remove the hosted card input fields from the DOM:

1cardManager.removeHostedInputs()

typescript

copy

Detect card type

When the user enters the card credentials, Headless Universal Checkout automatically detects the possible types of the card.

Listen to the callback onCardMetadataChange on the card manager to receive the type of card.

12345const cardManager = await headless.createPaymentMethodManager('PAYMENT_CARD', {    onCardMetadataChange({ type }) {        console.log('Card type: ', type)    },})

typescript

copy

Capture cardholder name

You are free to render the cardholder name input however you want.

As the user enters their cardholder name, call setCardholderName(cardholderName) to pass the cardholder name to the cardManager:

123cardholderNameInput.addEventListener('change', e => {    cardManager.setCardholderName(e.target.value)})

typescript

copy

If the cardholder name is required, its content will be validated by Headless Universal Checkout.

You can specify whether the cardholder name is required by setting an option when initializing Headless Universal Checkout:

1234567await headless.configure({    card: {        cardholderName: {            required: true,        },    },})

typescript

copy

Handle input errors

The event change, available on each input, reacts to input changes. This returns if the input is valid or not, and the error type.

123cardNumberInput.addEventListener('change', (...args) => {    console.log('cardNumberInput changed', ...args)})

typescript

copy

Validate and Submit

When the user submits the card information, follow the following flow:

First, validate all the inputs using the validate() function that does basic validations on the hosted inputs.
Then, submit the validated data using the submit() function. This triggers the payment creation.

For example, if the user clicks submit, you can handle it as follows:

12345678submitButton.addEventListener('click', async () => {    // Validate your card input data    const { valid } = await cardManager.validate()    if (valid) {        // Submit the card input data to Primer for tokenization        await cardManager.submit()    }   }})

typescript

copy

Calling submit() triggers the creation and handling of the payment.

If onCheckoutComplete is called, show a success message and reset the inputs.
If onCheckoutFail is called, show a failure message and allow the customer to try again with the same details.

Prepare 3DS

When the user pays by card, the Workflow will decide whether a 3DS challenge is required or not. If so, Headless Universal Checkout will automatically render the 3DS challenge in context.

To improve 3DS success rates, it is recommended to pass the following elements in the Client Session:

customer.emailAddress
customer.billingAddress

Integration example snippet

Below is an example code snippet of how it all fits together.

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182const container = document.getElementById('my-container')
// Create containers for your hosted inputsconst cardNumberInputId = 'checkout-card-number-input'const cardNumberInputEl = document.createElement('div')cardNumberInputEl.setAttribute('id', cardNumberInputId)
const cardExpiryInputId = 'checkout-card-expiry-input'const cardExpiryInputEl = document.createElement('div')cardExpiryInputEl.setAttribute('id', cardExpiryInputId)
const cardCvvInputId = 'checkout-card-cvv-input'const cardCvvInputEl = document.createElement('div')cardCvvInputEl.setAttribute('id', cardCvvInputId)
const cardHolderInputId = 'checkout-card-holder-input'const cardHolderInputEl = document.createElement('input')cardHolderInputEl.setAttribute('id', cardHolderInputId)cardHolderInputEl.setAttribute('placeholder', 'Cardholder Name')
const submitButton = document.createElement('input')const buttonId = 'submit-button'submitButton.setAttribute('type', 'button')submitButton.setAttribute('id', buttonId)submitButton.value = 'Submit'
// Add them to your containercontainer.append(cardNumberInputEl, cardExpiryInputEl, cardCvvInputEl, cardHolderInputEl, submitButton)async function configureCardForm() {    const baseStyles = {        height: 'auto',        border: '1px solid rgb(0 0 0 / 10%)',        borderRadius: '2px',        padding: '12px',        boxShadow: '0 4px 8px 0 rgba(0,0,0,0.2)',    }
    // Create the payment method manager    const cardManager = await headless.createPaymentMethodManager('PAYMENT_CARD')
    // Create the hosted inputs    const { cardNumberInput, expiryInput, cvvInput } = cardManager.createHostedInputs()
    await Promise.all([        cardNumberInput.render(cardNumberInputId, {            placeholder: '1234 1234 1234 1234',            ariaLabel: 'Card number',            style: baseStyles,        }),        expiryInput.render(cardExpiryInputId, {            placeholder: 'MM/YY',            ariaLabel: 'Expiry date',            style: baseStyles,        }),        cvvInput.render(cardCvvInputId, {            placeholder: '123',            ariaLabel: 'CVV',            style: baseStyles,        }),    ])
    // Set the cardholder name if it changes    document.getElementById(cardHolderInputId).addEventListener('change', e => {        cardManager.setCardholderName(e.target.value)    })
    // Configure event listeners for supported events    cardNumberInput.addEventListener('change', (...args) => {        console.log('cardNumberInput changed', ...args)    })
    cardNumberInput.focus()
    submitButton.addEventListener('click', async () => {        // Validate your card input data        const { valid } = await cardManager.validate()        if (valid) {            // Submit the card input data to Primer for tokenization            await cardManager.submit()        }    })}

typescript

copy

See more options and events in the SDK API Reference

Step 4.b: Handle payment methods with native buttons

This applies to PayPal, Apple Pay and Google Pay.

Some payment methods require Primer to manage the payment method’s button and implementation, and only require you to display the button to your customer.

Follow this approach when PAYPAL, APPLE_PAY or GOOGLE_PAY is available as a payment method and provided via onAvailablePaymentMethodsLoad.

Render the button

Get started by creating the payment method manager:

1const paymentMethodManager = await headless.createPaymentMethodManager('PAYPAL') // or APPLE_PAY / GOOGLE_PAY

typescript

copy

Then, create an instance of a payment method button and render it:

1234567891011// Create the button containerconst payPalButton = document.createElement('div')const payPalButtonId = 'paypal-button'payPalButton.setAttribute('type', 'button')payPalButton.setAttribute('id', payPalButtonId)
// Create and render the buttonconst button = paymentMethodManager.createButton()button.render(payPalButtonId, {    buttonColor: 'silver',})

typescript

copy

See additional style options in the SDK API Reference.

Handle button clicks (optional)

When the payment method button is clicked, Headless Universal Checkout automatically handles the rendering of the payment method screen and the payment. Based on the result of the payment, you should handle different callbacks.

If onCheckoutComplete is called, show a success message and hide the button.
If onCheckoutFail is called, show a failure message and allow the customer to try again.

You can also listen to the click event for logging or analytics purposes:

1234button.addEventListener('click', () => {    // React to click    // E.g. send off analytics})

typescript

copy

Other button methods

The button object also supports other methods:

1234567891011// Hide the buttonbutton.clean()
// Set the button to disabledbutton.setDisabled(true | false)
// Focus the button (not supported for PayPal)button.focus()
// Unfocus the button (not supported for PayPal)button.blur()

typescript

copy

Integration example snippet

Below is an example code snippet of how it all fits together.

123456789101112131415// Create your button containerconst payPalButton = document.createElement('div')const payPalButtonId = 'paypal-button'payPalButton.setAttribute('type', 'button')payPalButton.setAttribute('id', payPalButtonId)
function configurePayPalButton() {    // Create the payment method manager    const button = paymentMethodManager.createButton()
    // Render the button    button.render(paypalButtonId, {        buttonColor: 'silver',    })}

typescript

copy

Step 4.c: Handle payment methods with redirect

Some payment methods require redirecting to another web page in order to capture payment details.

Headless checkout automatically renders that web page in a popup window in order to maintain the current context.

Get started by creating a payment method manager:

1const manager = await headless.createPaymentMethodManager(paymentMethod.type)

typescript

copy

When the user has selected the payment method, call the start function. This function automatically:

opens a popup to present a loading indicator, then the payment method web page
shows an overlay on top of your page that prompts the user to focus on the popup

123myButton.addEventListener('click', () => {    manager.start()})

typescript

copy

Make sure start is called synchronously after a click

start opens a popup. However, most browsers have strict popup-blocking rules to protect the user. One such rule is to only allow popups that result from a direct user action.

Therefore, to ensure that the popup is properly rendered, make sure to call this function immediately after a user click.

If the browser cannot open popup windows, the current window will be redirected instead.

To ensure maximum compatibility, read the guide on how to handle redirects.