Shopify AI chatbot in theme.liquid, for the questions before checkout

Most of what a shopper asks before buying is already written on your store, such as how long delivery takes, whether they can send something back and how a size runs. Deacon answers those from your own pages and links the page each answer came from. There is no app to install from the Shopify App Store, and nothing is connected to your admin. You can start on the free plan, 50 answers a month without a card.

Putting it in theme.liquid

In your Shopify admin, go to Online Store, open the three-dot menu beside your live theme and choose Edit code. The file you want is theme.liquid, in the Layout folder. Paste the snippet from Deacon’s Install page on the line above </body> and save. The install guide covers the Install page and everything else on the dashboard side.

Shopify’s guide to editing theme code tells you to duplicate the theme before you touch it, so there is a copy to go back to.

Shipping, returns and sizing

Shopify publishes store policies at the same paths on every store. Your shipping policy is at /policies/shipping-policy on your own domain, and your returns policy is at /policies/refund-policy. Shopify’s page on store policies lists the rest, and says its free themes link the shipping policy from product pages and the cart once you have written one.

Add those two addresses to Deacon one at a time instead of crawling the whole store. A crawl of a store turns up mostly product pages, while a single address is learned straight away. From then on, an answer about delivery or returns links the policy it was taken from. Add your FAQ page the same way if you have one.

Product pages are worth adding when the description answers real questions, such as what a jacket is made of or whether it can go in the wash. Deacon can then answer “is this waterproof?” from your own description and link the product.

Where it stops

theme.liquid is the default layout for every page of your store outside the checkout, and the checkout no longer runs theme code at all. Both come from Shopify’s layout documentation, as it stood on 18 September 2026. So Deacon is on your home page, collections, product pages, cart, blog and policies, and not in the checkout or on the thank you and order status pages after it.

Deacon has no connection to your Shopify admin, so it cannot see an order.

It cannot say where a parcel is, what is in stock right now or whether a refund has gone through. “Where is my order?” is about the shopper’s own order, so Deacon tells them it cannot see it and asks for their email, and the conversation comes to you as a handoff. On the Instructions page, the draft asks for the one detail you always end up emailing back for. Put the order number there, and Deacon asks for it before it hands over.

It also learns a page as it read it that day, and nothing goes back to check. Change a price or a delivery estimate and Deacon keeps giving the old one until you choose Re-fetch on that page in Knowledge Sources and then press Retrain agent. If your prices change every week, leave the product pages unticked and let shoppers read the price on the page itself.

After a theme update

When you add a newer version of your theme to your draft themes, Shopify calls it “Updated copy of” your theme and tries to bring your code edits across. The theme card then says either “code edits successfully included” or “code edits could not be included”. If it says the second, paste the Deacon snippet into the new copy’s theme.liquid before you publish it. Shopify’s guide to updating themes has the rest.

A switch to a different theme altogether never brings the snippet with it, so paste it into the new one before you publish.