Crypto Payments Integration Process

Generate Payment Request URL

Much like Pay By Bank, cryptocurrency payment creation is protected by a client token. You'll need to follow the steps described in the client token guide to obtain a client token with the client_paymentrequest scope. To create a payment initiation request, you'll need to ensure that the feature is enabled on your client.

To create the request, a GraphQL mutation is used to specify the requested amount, references and merchant information.

An example of a GraphQL request to create a payment initiation request with the crypto payment method is shown below:

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The following table outlines the possible inputs for Crypto payments:

Status	Description
enabled	Boolean field used to specify enable or disable Crypto payments. Note that by default, this method is disabled.

Crypto Payment Method Details

Please note that:

• The paymentMethods.crypto type requires client configuration. Contact the technical team to assist in enabling your client for this feature.
• The amount that the user should pay to you should still be specified in the fiat currency (such as ZAR). Stitch will handle the conversion from cryptocurrency to fiat.
• Currently, BTC and ETH are supported for users to make payment with.

Expiring payment requests

It is highly recommended that an expireAt Date (ISO 8061) is supplied in the creation of any payment initiation request. At the specified date and time, the payment request status will automatically move to PaymentInitiationRequestExpired, if the payment is not yet successfully completed.

Surface URL and Handle Callback

The URL returned by the API requires that a whitelisted redirect_uri is appended to it as a query string argument. If you direct a user to this URL, they will be guided through the process of completing the payment. For test clients, we do have the following URLs whitelisted by default:

• https://localhost:8080
• https://localhost:8080/return
• https://localhost:3000
• https://localhost:3000/return
• https://localhost:9000
• https://localhost:9000/return

For example, if your whitelist URL configuration included the URL https://example.com/payment for payment requests, you'd append the following query string to the url returned from the API: ?redirect_uri=https%3A%2F%2Fexample.com%2Fpayment. The full URL you expose to the user should look like this

https://secure.stitch.money/connect/payment-request/2b068bd5-6a5a-42e1-8a45-673cb3ede612?redirect_uri=https%3A%2F%2Fexample.com%2Fpayment

Whitelisting Redirect URLs

To add or remove a URL from the whitelist, please reach out to a Stitch Engineer via our Support Form

Please note that production clients will not be allowed to use unsecure redirect_uri params such as http. For example

http://example.com/payment ❌

https://example.com/payment ✅

Once the user completes or cancels the payment request, they'll be redirected back to the redirect_uri. The below query string parameters will be passed back to the redirect_uri.

Request Field	Description	Type
id	The unique id of this payment request	ID
status	Status will have the value closed if the user clicks 'I've paid', or chooses to close the UI, or failed if something went wrong when generating the crypto payment details	String
payment_method	The method used to complete the payment, which would be crypto in this case	String
externalReference	The value that was provided to the externalReference field when the payment initiation request was created. It can be used to correlate transaction IDs within your system with the payment request initiated by Stitch	String

The id can be used to retrieve the final payment request status and other details from the Stitch API, as well as relate to incoming webhooks.

danger

The status field should not be used for any database operations since an external party can tweak it. To secure yourself from attackers who can send a fake payload to your redirect or webhook endpoint, we recommend:

1. using the webhooks as the source of truth as they are secure and will always be sent from Stitch.
2. making use of signed webhooks since you'll be able to verify the signature of each incoming webhook's request payload.

Using the webhooks also ensures you'll still be able to know the final status of a payment request if for example the request times out due to a network issue.

Using Multiple Internal Redirect URIs

For a situation where different callbacks lead to different internal URLs, you SHOULD have a single whitelisted redirect URL which can then have the logic handling the Stitch callback and redirect to the internal URLs. An overview of how to do this in NodeJS is as shown below:

const status = params.status;

switch (status) {
  case "closed":
    redirect("/crypto-processing");
  case "failed":
    redirect("/crypto-retry");
  default:
    break;
}

Note that if an expiry time is provided, this needs to be at least one hour from payment creation, in the case of crypto payments. This is due to a user being able to fulfil their crypto payment within the Stitch UI,

Cancelling Pending Payment Initiation Requests

If the user clicks the X on the dialog box, the payment initiation request will remain in the PaymentInitiationRequestPending status. To cancel the payment request, you should call the clientPaymentInitiationRequestCancel mutation, which also triggers the cancel webhook event.

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Payment Initiation Request Statuses

The table below describes the different statuses a Crypto request can have, with the initial status always being PaymentInitiationRequestPending:

Status	Description
PaymentInitiationRequestCompleted	This is a final payment state.
PaymentInitiationRequestPending	The user hasn't yet completed the payment initiation request, or they exited the Stitch dialog box before completing the bank selection process.
PaymentInitiationRequestCancelled	The payment initiation request was manually cancelled by the client. More information on this can be found here.
PaymentInitiationRequestExpired	The payment initiation request has expired while awaiting user interaction. More information on this can be found here.

Subscribe to Webhooks

Since Crypto payments are made similarly to Pay By Bank, we subscribe to webhooks and receive payment updates in the same way.

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If the subscription is successfully created, the body returned by the request will look like the sample in the Example Response tab in widget above.

For more information on receiving webhook events, listing active webhook subscriptions, unsubscribing from webhooks and validating signed webhook subscriptions, please visit the Webhooks page.

Webhook Statuses

When subscribed to the payment webhook filter type (applicable to Crypto and Pay By Bank requests), webhook updates will be sent whenever a payment request status is changed from the PaymentInitiationRequestPending state. This means that you will receive webhooks for each of the following payment request statuses:

• PaymentInitiationRequestCompleted
• PaymentInitiationRequestCancelled
• PaymentInitiationRequestExpired

Retrieving Payment Request Status

The status of a Crypto request works much like Pay By Bank.

To determine if and how a payment request was completed, we will need to retrieve its status.

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The two pieces of information you need from the response at this stage are the payment request id, and the url. The payment request id is used to correlate responses and to look up the status of the request in the API, and so should be retained for later usage. The url is used to enable the user to authorize the payment request, and you'll need to redirect the user to this URL. We'll cover this in the next section.

Integrating Using an Iframe

If you are integrating SafeLink into your web application using an iframe, you will need to configure the allow attribute to enable users to copy the deposit details for easy input into their chosen cryptocurrency app.

The allow attribute should be set as follows:

<iframe
  src="https://secure.stitch.money/connect/payment-request/0957174c-a600-4f7a-ac81-21a696338b0c?redirect_uri=https%3A%2F%2Fexample.com%2Fpayment"
  allow="clipboard-write https://secure.stitch.money"
></iframe>

Testing Crypto Payment Initiation

To test this process on your browser and run all the GraphQL examples in this guide prior to integrating with Stitch, you can use our sandbox. Learn more about the sandbox here.

Simulating Completed Payment Requests

We can simulate a user completing a payment request with crypto using the following mutation.

• We specify the payment request we want to complete with an ID and choose the method we want to complete it with.
• In relation to crypto payments, the field completedWith must be specified as crypto.
• This mutation will mark a payment request as COMPLETED to simulate that funds have been received. If payment webhooks are subscribed to, a webhook will also be sent for this status update.

Please note that you must first create a payment request and that it can only be completed once.

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Simulating the different statuses for Payment Requests

For testing purposes, certain amounts can be specified as part of the payment request to simulate different scenarios. The table below shows the different amounts and status mappings:

Amount	Status
1	UNDERPAID (User pays less than the expected amount)
2	COMPLETE (User pays the correct amount)
3	OVERPAID (User pays more than the expected amount)
4	LATE (User doesn't pay within the specified payment window)
5	BLOCKED (User's account is prevented from making transactions e.g. transaction limit reached)

Note:

• This only applies to test clients.
• These status changes are triggered 30 seconds after the request is made.