Create your first function

This guide walks you through building a real function — free shipping on orders over $150 — from start to finish. The same steps work for every kind of function.

Before you start

1. Install FunctionFlow AI from the Shopify App Store and open it from Apps in your Shopify admin.
2. Choose a plan. Every plan starts with a free trial and is billed through your Shopify invoice. See Plans and billing.

Step 1: Pick what you want to do

On Home, click Create function (or open Functions and click Create function). You’ll see What do you want to do? — every starting point, grouped by kind.

Type what you’re after in the search box — for example free shipping — or open the Shipping tab and choose Free shipping. The builder opens with the rule already set up.

Tip: Not sure where to start? Start from a template gives you complete, tested rules, and Describe it to AI builds one from a sentence.

Step 2: Adjust the rule

The builder has everything on one page:

1. Title — for discounts, customers see it at checkout next to the discount (for example Free shipping). For other kinds it’s only shown to your team.
2. When — the conditions. Here, Cart total is at least 150.
3. Then — the action. Here, Free / discounted shipping set to Free shipping.

Check the What it does card in the sidebar: it should read “Free shipping when the cart total is at least $150.” If it doesn’t say what you mean, adjust the conditions until it does.

Click Save draft to keep your work. Nothing reaches your checkout until you publish.

Step 3: Test it on a sample cart

The Quick test card runs the real compiled function against a sample cart — before anything is published.

1. Click Edit cart to see the sample cart: two products worth $250, a logged-in customer and a US address. Change anything you like.
2. Leave I expect the rule to apply selected and click Run test.

Try a cart under $150 with I expect the rule NOT to apply too. If a result surprises you, the Why section shows which condition didn’t match and what the cart had. More in Test a function.

Step 4: Publish in test mode

Click Publish… in the top right. FunctionFlow asks how the function should go live:

Choose Test mode first and click Publish in test mode. The function is now live in your store, but only for customers with the tag ff-test.

Step 5: Try it in your real checkout

1. In Shopify admin, open Customers, find your own customer account and add the tag ff-test.
2. In your online store, log in with that account, add more than $150 of products to the cart and go to checkout. Shipping should be free.
3. Log out, or use a private window, and check out again: customers without the tag see your normal checkout.

Step 6: Go live for everyone

Back in FunctionFlow, open the function. In the sidebar’s Test mode card, click Go live for everyone. That’s it — every customer now gets free shipping over $150.

What’s next

• See how often the rule is used in Analytics.
• Learn every option in the visual builder and conditions.
• Schedule a rule for a sale with active dates.