Stripe Integration with Webhook Flows

Several nonprofits have reached out regarding Stripe integration recipes. Stripe webhooks and checkout session callouts are typical use cases. These inbound and outbound examples will assist with many payment scenarios.


How to create Checkout Sessions

Checkout Sessions are special links that redirect the user to Stripe. The link includes their shopping cart contents. Stripe collects payment, then redirects the user back to Salesforce.

In this example we will create the checkout session (highlighted above) using a script. The checkout session collects payment when the user finishes a screen flow.


Step 1 - In Stripe, obtain your API keys in Test Mode


Step 2 - In Salesforce, create a Named Credential to hold your API keys


Step 3 - Build the Screen Flow

# Streamscript to create a Stripe Checkout Session
$url = 'callout:https_api_stripe_com/v1/checkout/sessions'
$headers = {}
$headers.Content-Type = 'application/x-www-form-urlencoded'
$headers.Authorization = 'Bearer {!$Credential.Password}'

# Shopping cart
$params = {}
$params.cancel_url = ''
$params.success_url = ''
$params.put('line_items[0][name]', 'GenWatt Diesel 1000kW')
$params.put('line_items[0][quantity]', 2)
$params.put('line_items[0][amount]', 99900)
$params.put('line_items[0][currency]', 'USD')

# Form-encoded POST
$payload = $params.toUrl();
$response = Http-Post $url $headers $payload
$result = Json-Decode $response.body
return $result.url

Comments: This script uses the protected fields of a Named Credential as a best practice.
Refer to the Salesforce docs for an explanation on how the callout and $Credential merge fields work.


Comments: By using rich text you can display a clickable hyperlink to the user. It is a good place to set expectations about opening a new window and having the card ready. This pattern may also be used with flows in sites/communities.


The checkout flow is ready!


How to receive Stripe webhooks

Webhooks listen for Stripe activities like subscription payments sent to Salesforce. We collect these events in the Streams Package and execute flows to handle them. Here's how:


Step 1 - In Salesforce, prepare the webhook flow


Step 2 - In Stripe, add the webhook endpoint in Test Mode


Step 3 - In Salesforce, verify webhook requests and store them

# Streamscript to verify the signature
$key = Base64-Encode {!Stripe_mdt}.Secret__c
$timestamp = $Webhook.requestHeaders.Stripe-Signature.substr(2, 12)
$hmac = Hex-Decode $Webhook.requestHeaders.Stripe-Signature.substr(16, 80)
$input = Base64-Encode `$timestamp.$Webhook.request`
if (!Crypto-Verify-Hmac 'hmacSHA256' $input $key $hmac) {throw $hmac}

# Parse the incoming payload
$event = Json-Decode $Webhook.request

# Prepare a task
$Task = New-Task
$Task.Subject = $event.type
$Task.Description = Json-Encode $
return $Task

Comments: first the script verifies the signature using protected fields of a Custom Metadata Type as a best practice. Refer to the Salesforce docs for an explanation on how the formula works. Then it converts the payload into a Task record. Using the fields of a record allows us to return several values at once from the script. We set the task's subject to the event type, so that a decision can be made in the next flow step.


Step 4 - Decide how to handle each event type

Insert a task record for each webhook request:

Finally click the gearwheel to enable the Site Guest User to insert records safely.
In Flow Properties > Advanced > How to Run the Flow: System Context With Sharing.

The saved record provides an audit trail. Use a scheduled flow to process the task records in the context of an integration user. The customer data payload is in the Description field.

The webhook is ready! Use the Resend button in Stripe to iterate and test.

That's basic two-way integration covered. We hope you find our documentation useful, and we sincerely welcome feedback: Contact Us »



Getting started with Streamscript
Install from the Salesforce AppExchange
Package install link: /packaging/installPackage.apexp?p0=04t7F000005N1wy