How to Apply Customer Tag-Based Discounts with Shopify Functions

Prerequisites:

1. Shopify Partner account.
2. Shopify CLI installed.
3. Node.js installed.

Step 1: Create a New App with Shopify CLI

shopify app create

Follow the prompts to set up your app. Choose Node.js as the language.

Step 2: Add Shopify Functions to Your App

shopify app generate extension

Select Discount as the type of extension.

Step 3: Develop the Function Logic

Navigate to the extensions directory in your app, and open the discount function folder. Inside the src directory, modify function.js (or index.js depending on your setup) to include the logic for customer tag-based discounts.

src/function.js

import { extend } from '@shopify/checkout-ui-extensions';

extend('checkout.discount', async (discounts) => {
  // Get customer tags from the buyer
  const customerTags = await fetchCustomerTags();

  // Define your tag-based discount rules
  const discountRules = [
    { tag: 'VIP', discount: 20 },
    { tag: 'Loyal', discount: 15 },
    { tag: 'New', discount: 10 }
  ];

  // Find the highest discount applicable based on customer tags
  let maxDiscount = 0;
  customerTags.forEach(tag => {
    const rule = discountRules.find(rule => rule.tag === tag);
    if (rule && rule.discount > maxDiscount) {
      maxDiscount = rule.discount;
    }
  });

  // Apply the discount if any
  if (maxDiscount > 0) {
    discounts.apply({
      percentage: maxDiscount,
      message: `You received a ${maxDiscount}% discount for being a valued customer!`
    });
  }
});

async function fetchCustomerTags() {
  // Replace with actual logic to fetch customer tags
  // For demonstration, return a static list of tags
  return ['VIP', 'New'];
}

Step 4: Deploy the Function

Deploy your app and function to Shopify using the following commands:

shopify app deploy
shopify app publish

Step 5: Update Shopify Admin to Use Your Function

1. In your Shopify admin, navigate to Settings > Checkout > Discounts.
2. Enable the new discount extension and configure it to apply the discount based on customer tags.

Step 6: Testing

Test the discount by creating a customer with the appropriate tags and checking out. The discount should automatically apply based on the customer’s tags.

Explanation:

1. Customer Tags Fetching: Replace fetchCustomerTags with logic to fetch actual customer tags, possibly using the Shopify Admin API.
2. Discount Rules: Define the discount rules based on customer tags.
3. Applying Discounts: The function checks the customer’s tags and applies the highest applicable discount.
4. Deployment: Deploy and publish your function, then enable it in your Shopify admin.

This example provides a basic structure for creating a customer tag-based discount function. You can customize it further based on your requirements.