Cart GSTIN Theme App Extension

SuperGST includes a lightweight Online Store 2.0 Theme App Extension (GST Invoice Capture) that integrates natively into merchant themes (Dawn, Refresh, Impulse, Prestige, etc.).

It provides a clean, responsive card on your cart drawer or cart page:

• Heading: "Business Purchase? Claim Your GST Credit"
• Company Name: attributes[Company Name]
• Buyer GSTIN: attributes[GSTIN] with real-time 15-character validation

When a customer enters their 15-character GSTIN, client-side validation instantly verifies the format. Upon validity, it saves the details to Shopify cart attributes via /cart/update.js, which seamlessly flow into the order's note_attributes.

• 1
  Log into your Shopify Admin and navigate to Online Store > Themes.
• 2
  Click Customize next to your active theme.
• 3
  In the top template selector dropdown, select Cart (or open your Cart Drawer).
• 4
  In the left sidebar panel, click Add block or check App embeds.
• 5
  Find GST Invoice Capture and click to add it.
• 6
  Drag the block to your preferred position (typically directly above the Checkout button).
• 7
  Click Save in the top right corner.

In the Theme Editor block settings, you can customize:

• Title text (e.g., "Business Purchase? Claim Your GST Credit").
• Subtitle instructions.
• Company Name field placeholder and label.
• GSTIN field placeholder and label.
• Custom error messages displayed if a buyer inputs an invalid GSTIN format.
• Top and bottom margin spacing to match your theme layout.