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September 8, 2026 · 5 min

Building a custom Shopify app: why and how

When a custom Shopify app pays off, what it can do, and the steps to build it — and even publish it on the App Store.

When Shopify App Store apps don’t cover your need, a custom app takes over. It plugs into Shopify’s APIs to automate your exact process. Here’s when it’s worth it and how it works.

Public app vs custom app

A public app (from the store) is built for the many: convenient, but generic. A custom app is developed for your store only: it does exactly what you need, with no bloat and no third-party monthly fee forced on you.

When to build a custom app

  • A specific business process no app covers
  • An integration with your ERP, CRM or management software
  • Automation (orders, inventory, B2B pricing)
  • A unique customer feature that sets you apart

What an app can do

  • Automate repetitive back-office tasks
  • Sync Shopify with external tools
  • Add features on the storefront
  • Process and enrich your product or customer data

The steps

  • Scope the need and use cases
  • Technical design (Shopify APIs, webhooks, permissions)
  • Development and testing
  • Deployment, then maintenance
  • Optional publishing on the Shopify App Store

Our experience

We designed and shipped two apps on the Shopify App Store: ShopAudit (AI audit of SEO, speed and conversion) and SizeGuide (AI size recommendation to cut returns). So we know the whole path, from idea to publishing.

Need a Shopify app or automation? Let’s talk — free quote within 24h.

FAQ

What’s the difference between a public app and a custom app?

The public one comes from the store and is generic; the custom one is developed for your store and does exactly what you need.

Do I have to publish the app on the Shopify App Store?

Not necessarily. A private/custom app can stay reserved to your store. Publishing only makes sense if you want to offer it to other merchants.

How much does a custom Shopify app cost?

It depends on complexity and integrations. We scope it then give a range; free quote within 24h.

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