Custom Apps.
Custom Shopify apps extend a single merchant's store with Admin API workflows, webhooks, embedded admin tools, and app extensions for checkout, admin, and theme. Athom.Agency builds these apps for operations and integrations that off-the-shelf App Store products cannot cover cleanly.
01The work
Custom Shopify apps.
A custom Shopify app is software built for one merchant (or one organisation), installed on their store, and owned as part of their stack. It is the right tool when App Store products stop short: unique workflows, deep integrations, or admin tools that match how the business actually runs.
We build custom apps with the Admin API, webhooks, embedded admin UI, and Shopify app extensions for checkout, admin, and the theme. The goal is reliable automation and clearer operations inside Shopify, not a public App Store listing.
Custom app work typically includes:
Admin API and embedded admin.
We build merchant-facing tools that live inside Shopify admin: dashboards, bulk actions, configuration screens, and workflows that staff use every day without leaving the platform.
Webhooks and background jobs.
Orders, inventory, customers, and fulfilment events trigger your systems in near real time. We design idempotent handlers, retries, and logging so automation stays trustworthy as volume grows.
Checkout, admin, and theme extensions.
When the workflow needs to appear at checkout, in admin, or on the storefront, we use Shopify app extensions so the experience feels native instead of bolted on.
Integrations and headless companions.
ERP, PIM, fulfilment, and internal tools connect through the app layer. If the storefront itself is custom, we align the app with our Headless Shopify work so APIs and data models stay consistent.
02Next
Built for one merchant, maintained like product?
Custom apps succeed when scope is clear: which jobs the app owns, which stay in Shopify native features, and what never belongs in the storefront theme. We write that boundary first, then implement against it.
Delivery includes authentication, environments, and documentation so your team (or ours on retainer) can operate the app after launch. You get software fitted to your store, not a generic package you have to work around.
Need a custom Shopify app or integration? Get in touch. We will map the workflow and recommend app, theme, or headless before we build.
Certified by Shopify
Shopify Select Partner.
Shopify Select Partner, building on Shopify since 2021
03Questions
FAQ.
01What is a custom Shopify app?
A custom Shopify app is an application built for a specific merchant, installed on their store, and used to extend admin workflows, automate operations, or connect external systems. Unlike public App Store apps, it is not distributed to other merchants. Athom.Agency builds these apps around the Admin API, webhooks, and Shopify app extensions.
02When should I choose a custom app instead of an App Store app?
Choose a custom app when existing apps cannot cover your process without fragile workarounds, when you need tight ERP, PIM, or fulfilment integration, or when staff need admin tools that match your exact workflow. If a well-supported App Store app already solves the problem cleanly, we recommend that first.
03Can a custom app work with a headless storefront?
Yes. Custom apps often power backend workflows while a Hydrogen or Next.js storefront handles browsing. We keep Admin API and Storefront API responsibilities separated so the app and storefront stay maintainable together.
04Do you publish apps to the Shopify App Store?
These engagements focus on custom apps for your store (or organisation), not public App Store listings. If you later want a public product, that is a separate product and partnership track.