Shopify Functions in 2026: Custom Logic and Shopify App Development

What are Shopify Functions?

Shopify Functions is the framework through which an app can act at specific points in Shopify commerce logic without relying on JavaScript running in the customer's browser. A Function is developed as part of an app and Shopify executes it in its infrastructure when the supported event occurs.

Current official documentation is available on Shopify.dev.

What can they be used for?

Available APIs evolve over time, but the principle stays the same: a Function should be chosen because an official extension point exists for the requirement. Examples include discounts, payment or delivery customizations, cart validations and other documented commerce logic.

I do not treat “Shopify Functions” as a generic answer to any custom request. I first verify:

• whether Shopify exposes a suitable Function API;
• whether that API is available on the merchant's plan and context;
• whether the solution must be distributed through a public app;
• whether automation, native configuration or another API would be simpler to maintain.

Are Shopify Functions available on Basic, Shopify and Advanced?

Yes. Merchants on these plans can use public Shopify App Store apps that contain Functions. Not every distribution model and not every Function API has the same availability.

This matters in my work: I do not propose a function that cannot actually be installed or distributed in the merchant's context. If the requested API is outside the plan's scope, I use a technically correct alternative or state the limitation before development.

Functions and Shopify app development

A Function is not a code fragment to paste into the theme. It is part of a Shopify app with its own configuration, extensions, deployment and maintenance cycle.

A typical project can include:

1. analysis of the commercial requirement;
2. verification of the available Shopify API;
3. definition of Function inputs;
4. development and testing of the logic;
5. integration with the app that manages configuration and data;
6. tests for valid scenarios, limits and errors;
7. deployment according to Shopify's supported distribution model.

Functions or Liquid?

Liquid and Shopify Functions solve different problems. Liquid mainly controls theme rendering and storefront presentation. A Function acts in backend points that Shopify explicitly makes extensible.

If I need to display information or build a section, the theme is usually the correct layer. If I need to apply a commerce rule supported by a Function API, the correct layer is the app.

Functions or automation?

Automation fits an asynchronous process, for example updating data after an event or sending information to another system. A Function fits logic Shopify must execute at the precise point exposed by the relevant API. Mixing the two levels often creates unnecessary complexity.

Performance and reliability

The architectural advantage is that the Function runs in Shopify's supported execution context rather than depending on a generic browser script. This does not justify promises of “zero latency”, “absolute stability” or automatic conversion increases: the logic still needs to be designed, tested and maintained correctly.

How I work with Shopify Functions

I am Francesco Guiducci, a freelance Shopify expert and Shopify app developer. In addition to themes, Liquid, audits and migrations, I design applications and integrations when a feature requires dedicated software.

I work with clients on Basic, Shopify and Advanced. Before proposing a Function I always verify the relevant API and allowed distribution model; if it is not compatible with the project, I choose a different solution instead of selling a feature the merchant cannot use.

See Shopify App Development or request 1:1 Shopify consulting.

Updated September 3, 2026 based on current Shopify Functions documentation.