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Shopify Custom API Integrations: When and How to Build One

Updated , first published · 4 min read

A Shopify custom API integration is a small app built for your store alone that reads or writes your store’s data through Shopify’s APIs, for example to send orders to a warehouse system or pull stock levels from an ERP. Before paying for one, check three cheaper options in this order: an existing app on the Shopify App Store, a Shopify Flow workflow, and a no-code automation service such as Zapier. If none of them fits, a developer builds a custom app in Shopify’s Dev Dashboard, with access limited to the data it needs.

We build Shopify apps on these APIs, so this is the developer’s view written for merchants. Shopify facts come from the Help Center pages on installing and setting up apps, webhooks and Shopify Flow, read on October 23, 2026.

Try these first

  1. An existing app. Search the App Store for your system’s name plus “Shopify”. Connectors for common accounting, shipping, marketplace and CRM tools already exist, maintained by someone else.
  2. Shopify Flow. Flow’s actions can do anything the GraphQL Admin API allows, and apps add their own triggers and actions through connectors. Flow can also send an HTTP request to another system’s address, which covers many “when X happens, tell system Y” jobs without a custom app; Shopify’s Help Center says that action is available on the Shopify Plus, Advanced or Grow plans.
  3. A no-code automation service. Zapier and similar services connect Shopify to many other tools with triggers and actions you click together; see Zapier with Shopify.
  4. A custom app, when the data has to move in a specific shape, at volume, or with logic that none of the above can express.

How a custom app connects to your store

  • Created in the Dev Dashboard. In the admin go to Settings > Apps, click Develop apps, then Build apps in Dev Dashboard. There the developer creates the app, defines the API scopes (which data it may read or change), and releases versions. Each version can have its own configuration and scopes.
  • Scopes are the safety line. An integration that sends orders to a warehouse needs to read orders and write fulfillments; it has no reason to touch your discounts or customers’ marketing settings. Ask the developer for the list of scopes and why each is needed.
  • Installation. The app can be installed from the Dev Dashboard, or through an install link. Custom install links work only on the store they were made for and expire after seven days.
  • A developer installing it for you with a collaborator account needs the full Manage and install apps and channels permission and the Approve app charges permission.
  • Before you click Install, Shopify’s Install app screen lists the personal data and store data the app can view and edit. Compare it with the scopes you agreed.

Webhooks: let Shopify push events

Instead of asking Shopify for changes every few minutes, an integration can subscribe to webhooks: Shopify sends a message to a secure https:// address when an event happens, such as an order being paid or a product’s price changing. Categories include orders, products, inventory, customers, fulfillments, refunds, checkouts, discounts and more.

Two operational details from Shopify that matter to you as the owner: when a webhook created by an app fails, Shopify emails the store owner’s address; and if the receiving address keeps returning errors, the webhook subscription is deleted automatically. Make sure someone reads those emails, or the integration can stop silently. More on this in Shopify webhooks.

Brief for a developer

  • What data moves, in which direction, and which system is the source of truth for each field (for example, stock from the ERP, orders from Shopify).
  • How often: on each event (webhook) or on a schedule.
  • Volume: orders per day at peak, number of products and variants.
  • Failure handling: what happens when the other system is down, who gets alerted, and how missed events are resent.
  • Scopes: the minimum access the app needs, written down.
  • Ownership: the code and the app in your Dev Dashboard, documentation, and who maintains it after launch.

Finding a developer is covered in hire a Shopify Partner.

Costs and upkeep

The build is the visible cost. The ongoing ones: Shopify releases a new API version every three months and supports each for at least 12 months, so so integrations need updates; the systems on the other side change too; and someone has to watch failures. Budget for maintenance from the start, or prefer a maintained app when one exists. Our other operations guides are in the running a store hub.

Frequently asked questions

Can I connect my ERP to Shopify? Yes, through an existing connector app if one supports your ERP, or a custom app that uses Shopify’s APIs and webhooks. Start by searching the App Store for your ERP’s name.

Do custom apps need Shopify’s review? A custom app you create in the Dev Dashboard for your own store is installed directly or with a store-specific link; it is not published on the App Store, so it does not go through the App Store’s listing review. You still approve its access on the install screen.

Is the Shopify API free to use? Using Shopify’s APIs from your own custom app carries no separate Shopify charge that the pages read for this article list; the cost is the developer’s work and upkeep. Higher API limits are part of the Shopify Plus plan.