Migration
4 min to readLast update on 15 September 2026

Existing-Store Workflow

An existing store already has traffic, products, and a theme. The goal is to turn on Custy carefully so shoppers keep a smooth path while you finish setup.

What success looks like

You can install Custy, set up a few products, and test the Design Lab without taking the store offline. Shoppers only see Custy when you are ready.

Step 1: Install on the correct store

Sign in to the Shopify store that sells to customers. Install Custy there. Confirm the store name in the top bar before you click Install.

Step 2: Choose how shoppers will see Customize It

You can embed Custy on the live theme when you are ready, or test on a duplicate theme first. A duplicate theme is safer for busy stores.

  • Duplicate your live theme in Shopify (recommended for busy stores)
  • Embed Custy on the duplicate theme and preview it
  • Or embed on the live theme only after a quiet test window

Step 3: Sync products and set up a pilot set

Bring products into Custy and fully configure a small pilot set before you touch the whole catalog.

  • Sync products from Shopify into Custy
  • Pick a pilot list of products
  • Set sizes, colors, print areas, and pricing on the pilot set
  • Place a test order on a test product if your plan and store allow it

Step 4: Expand in batches

After the pilot works, migrate the next batch of products the same way. Keep a simple sheet of what is done and what is still on the old customizer.

Step 5: Switch shoppers, then clean up

When the checklist passes, publish the theme (or keep the live theme) with Custy as the customizer shoppers use. Remove old app buttons or blocks so shoppers are not offered two design tools.