Dynamic code generation with Punchh

A coupon code is a unique code that can be used by a single user (either single or multiple use). The Punchh framework generates coupon codes, which can be processed within a mobile app or at the point-of-sale (POS) system.

Using the Punchh coupon framework and Braze, you can achieve the following scenarios:

• Generate a coupon code when the guest clicks a coupon generation link in an email: The coupon code will be generated dynamically and shown on a web page.
• Generate a coupon code when the guest opens an email: The coupon code will be generated dynamically and shown as an image within the email.

Integrating dynamic coupon code generation

Step 1: Create a coupon campaign

1. Using a Punchh coupon campaign, create a dynamic generation coupon campaign as shown in the following image.
2. The Punchh coupon framework will generate the following parameters to enable dynamic coupon generation:
   • Dynamic coupon generation token: This is a system-generated security token for encryption.
   • Dynamic coupon generation URL: This URL will be embedded in the email as a link or image, as required by the business.

Step 2: Generate signature and construct URL

The JWT.IO library decodes, verifies, and generates JSON web tokens, an open, industry-standard RFC 7519 method for representing claims securely between two parties.

The following ClaimType names can be used to ensure the uniqueness of guests and coupons:

• campaign_id: represents the system-generated Punchh campaign ID.
• email: represents the user’s email address.
• first_name: captures the user’s first name.
• last_name: captures the user’s last name.

To use the Punchh dynamic coupon code API, a JWT Token must be constructed. Add the following Liquid template to your Braze dashboard in the message body of the channel you’d like to use:

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{% assign header = '{"alg":"HS256","typ":"JWT"}' | base64_encode | replace: '=', '' | replace: '+', '-' | replace: '/', '_' %}

{% capture payload_raw %}

{
  "campaign_id": "CAMPAIGN_ID",
  "email": "{{${email_address}}}",
  "first_name": "{{${first_name}}}",
  "last_name": "{{${last_name}}}"
}

{% endcapture %}

{% assign payload = payload_raw | replace: ' ', '' | replace: '\n', '' | base64_encode | replace: '=', '' | replace: '+', '-' | replace: '/', '_' %}

{% assign unsigned_token = header | append: "." | append: payload %}

{% assign secret = "DYNAMIC_COUPON_GENERATION_TOKEN" %}

{% assign signature_raw = unsigned_token | hmac_sha256_base64: secret %}

{% assign signature = signature_raw | replace: '=', '' | replace: '+', '-' | replace: '/', '_' %}

{% assign jwt = unsigned_token | append: "." | append: signature %}

Replace the following:

Step 3: Append coupon code to message body

Linking to Punchh web page

To link to a Puncch-hosted web page, add {{jwt}} to the dynamic generation URL you created earlier. Your link should be similar to the following:

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https://fakebrandz.punchh.com/request_coupons/7xY3bL9jRfZ1pA6mc8qD2eS4vT5wX?sign={{jwt}}

When a user clicks the coupon URL, they’ll be redirected to a Punchh-hosted web page, where their generated coupon will be displayed.

Extracting code via JSON as plain text

To return a JSON response, append {{jwt}} to the dynamic generation URL you created earlier, then add .json after the token in the URL string. Your link should be similar to the following:

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https://fakebrandz.punchh.com/request_coupons/7xY3bL9jRfZ1pA6mc8qD2eS4vT5wX.json?sign={{jwt}}

You could then leverage Connected Content to insert the code as plain text into any message body. For example:

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{% connected_content https://fakebrandz.punchh.com/request_coupons/7xY3bL9jRfZ1pA6mc8qD2eS4vT5wX.json?sign={{jwt}} :save punchh_coupon %}
{{punchh_coupon.coupon}}

Linking an image inside email content

To link the coupon code inside an image:

1. Append {{jwt}} to the dynamic generation URL you created earlier.
2. Add .png after the token in the URL string.
3. Embed your link in an HTML <img> tag.

• example input
• example output

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<img src="https://fakebrandz.punchh.com/request_coupons/7xY3bL9jRfZ1pA6mc8qD2eS4vT5wX.png?sign={{jwt}}">

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