Custom apps and integrations

Many stores don't need a public app at all, just a custom app: a private integration for one store, such as syncing inventory from a warehouse system or sending orders to an ERP. Custom apps work through the GraphQL Admin API and webhooks.

Shopify marked the REST Admin API as legacy on October 1, 2024, and new public apps submitted after April 1, 2025 must use GraphQL only, so new integrations should be built on GraphQL. Headless storefronts use the Storefront API, Shopify's GraphQL API for products, collections, cart and checkout.

What I build and review

  • ERP and inventory sync

    Products, stock and prices kept in step between Shopify and your system of record.

  • 3PL and fulfillment

    Orders out to the warehouse, tracking and stock back in.

  • App stack audits

    Value, cost, speed impact and overlap of every app you pay for.

How I approach integrations

Reliable, documented, maintainable

  1. Map the data flow

    What moves where, how often, which system is the source of truth, and what happens when a sync fails.

  2. Native and existing apps first

    Shopify now covers jobs that used to need apps, and many systems have official connectors. Custom code is for the gaps.

  3. Plan for API versions

    Shopify releases a new API version every quarter, and each stable version is supported for at least 12 months, so custom apps need planned updates.

  4. Watch the limits

    Integrations that throttle during peak are a sign to revisit the design, or one of the reasons to consider Plus and its higher API limits.

How to work together

Integrations are scoped in a build; the retainer covers ongoing changes.

  • Build

    Store Architecture & Build

    For: Entrepreneurs launching, brands replatforming or on old themes

    An architecture plan first, then a store built on it.

    What's included

    • Architecture plan: data model, apps, integrations and Markets
    • Online Store 2.0 theme build
    • Data migration
    • Launch QA
    Pricing
    Fixed price, from
    Price
    $8,000

  • Ongoing

    Growth Retainer

    For: Brands with steady traffic

    A set number of hours each month to keep the store improving.

    What's included

    • CRO tests
    • New sections and features
    • Speed work
    • Maintenance
    Pricing
    Monthly
    Price
    $2,500/month for 20 hours
All services

FAQ

Common questions

Do I need a public app or a custom app?

If a well-reviewed public app does the job, use it. A custom app makes sense for integrations unique to your business, such as your ERP or warehouse setup.

Do I need Shopify Plus for custom apps?

Not for most integrations. Custom apps that contain Shopify Function APIs do require Plus.

Will uninstalling an app remove its code?

Not always. Apps built with theme app extensions don't edit theme code, but some apps add code that isn't removed automatically, so check the theme after uninstalling.

Related specialties and guides

Related specialties

Further reading

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