How to Develop a Custom Shopify App
At some point, every growing Shopify store hits a wall that off the shelf apps simply cannot fix. Maybe you need a very specific order tagging workflow that matches how your warehouse actually operates. Maybe you’re trying to connect Shopify to an internal ERP or a custom CRM that no App Store integration was ever built for. Maybe your business logic is just genuinely unusual enough that no general-purpose app was ever going to cover it. This is exactly the situation custom Shopify apps were built to solve.
Unlike public apps, which are built for thousands of different merchants and have to be generic enough to work for all of them, a custom app is built for one specific store, with logic that’s shaped entirely around how that one business actually runs. If you’ve been wondering whether developing a custom app is realistic for your store, or you’re a developer trying to understand the current path from idea to a working app, this guide walks through the whole process from start to finish.
Custom App Versus Public App: Know Which One You’re Building
Before touching any code, it’s worth being clear on what kind of app you’re actually building, because the two paths diverge significantly. A custom app, sometimes still referred to by its older name of a private app, is created directly inside a specific store’s admin panel under Settings, then Apps and sales channels, then Develop apps. These custom apps are built for one specific store, created directly in that store’s admin, with no review process, no App Store listing, and none of the multi tenant complexity that comes with a public app.
A public app, on the other hand, is meant to be installed by many different merchants, gets listed in the Shopify App Store, and has to go through Shopify’s app review process before it becomes publicly available. If you’re building something purely for your own store’s internal use, like a custom reporting dashboard or a specific inventory sync with your supplier’s system, a custom app is almost always the right call, since it skips the review process entirely and gets you straight to a working tool. If you’re planning to eventually sell this as a product to other merchants, you’re building a public app from the start, and that changes several decisions you’ll make along the way, including how you handle billing and how carefully you need to design your onboarding flow.
When A Custom App Actually Makes Sense
Not every problem needs a custom built solution. Before committing development time and budget to this, it’s worth genuinely checking whether an existing app in the Shopify App Store already solves your problem. Given there are over 13,000 apps available, there’s a real chance someone has already built what you need, and a well reviewed existing app is almost always faster and cheaper than building your own.
Custom development starts to make sense specifically when your business logic is genuinely unique to how your company operates, things like custom order tagging rules, vendor-specific fulfillment workflows, or bespoke internal reporting that doesn’t map cleanly onto any existing app’s feature set. It also makes sense when you need to connect Shopify to internal systems that no public app has ever been built to talk to, such as a proprietary ERP, a custom built CRM, or a legacy warehouse management system your company has used for years. If your need falls into either of these buckets, building a custom app stops being a nice to have and starts being the only real option.
Setting Up Your Development Environment
Once you’ve confirmed a custom app is the right path, the setup process itself has gotten considerably smoother in recent years thanks to the Shopify CLI. Getting started involves creating a Shopify Partner account, setting up a development store, installing an active Node.js LTS version, and using the Shopify CLI to scaffold your app. The CLI handles the tedious parts of getting a new project running, including local development tunneling so Shopify can actually reach your local machine during testing, and eventually handles deployment as well.
For most apps today, Shopify recommends scaffolding with the React Router template, which is the current recommended path for building apps that users access from inside the Shopify admin. This represents a shift from the Remix based template that was standard for the past couple of years, though the underlying concepts carry over directly since React Router absorbed much of what Remix offered. A modern Shopify app today is essentially a full-stack application, and you’ll want to be comfortable with TypeScript, React, Node.js, basic database concepts, HTTP, environment variables, and GraphQL before diving in. If you’re coming from a general web development background rather than specifically an ecommerce one, this stack should feel familiar even if some of Shopify’s specific tooling around it is new to you.
It’s also worth knowing that if you’re building something simpler, like an integration that just needs API credentials without any embedded admin UI, Shopify’s Dev Dashboard lets you create an app there directly instead of going through the full scaffolding process, which can save a meaningful amount of setup time for straightforward integration work.
Understanding The Core Building Blocks
Every Shopify app, regardless of what specific problem it solves, is built around a handful of core technical pieces that work together. Getting comfortable with each of these individually makes the whole system click into place much faster.
The GraphQL Admin API is how your app actually reads and writes store data, whether that’s pulling product information, updating order tags, or creating new discount codes. This is used for querying or mutating Shopify admin data, and it’s the API layer you’ll spend the most time working with directly, since almost every meaningful feature in a custom app eventually involves either pulling data from the store or pushing changes back into it.
Webhooks are how your app gets notified when something happens in the store without you having to constantly poll for changes. These are callbacks sent by Shopify when certain events occur, such as a new order being placed or a product being updated, and they’re essential for any app that needs to react to store activity in near real time rather than checking periodically.
App Bridge and Polaris handle how your app actually looks and behaves once it’s embedded inside the Shopify admin. App Bridge is the library that lets your app work seamlessly within the Shopify admin interface, while Polaris is Shopify’s design system that lets your app create a Shopify like experience, meaning buttons, forms, and layouts that look and feel native rather than like a bolted on third party tool. Using Polaris components isn’t strictly mandatory, but it saves significant design time and gives your custom app a polished, professional feel without you having to build a UI component library from scratch.
Authentication, meanwhile, is handled largely for you if you’re using the official Shopify app framework packages. The relevant package enables your app to authenticate requests coming from Shopify and interact with Shopify’s APIs, keeping your app up to date with current best practices and security updates automatically. This matters more than it might initially seem, since authentication and OAuth flows are exactly the kind of thing that’s easy to get subtly wrong if you’re building it entirely from scratch, and Shopify’s maintained packages handle the edge cases for you.
Building Your First Real Feature
A helpful way to internalize how all these pieces fit together is to walk through building something concrete rather than staying purely theoretical. Shopify’s own tutorials often use a simple example: an app that generates QR codes for products, where scanning the code takes a shopper straight to checkout with that product already added, or to the product page directly. The tutorial covers scaffolding the app, updating a database included in the app template, using the core Shopify app package to authenticate users and query data, and using Polaris components to build a UI that follows Shopify’s design guidelines.
For a custom app specific to your own store, your equivalent “first feature” might be something like an order tagging tool that automatically labels every incoming order based on which warehouse zone it should ship from, or a simple internal dashboard that pulls inventory levels from Shopify and cross references them against your supplier’s stock feed. Whatever the specific feature, the pattern is largely the same: query or mutate data through the GraphQL Admin API, react to relevant events through webhooks if needed, build the interface using Polaris and App Bridge, and store any app specific data your app needs to persist, commonly using Prisma as the data layer. The standard template uses Prisma to store session data, by default using SQLite, though production apps using PostgreSQL or another relational database require some additional manual configuration work.
Hosting And Deployment Considerations
Once your app works locally, you need somewhere to actually host it, and the right choice depends heavily on what your app does and how often merchants interact with it. For a custom app serving a single store, the hosting requirements are typically modest compared to what a public app serving thousands of merchants would need.
For webhook-driven apps that mostly process events in the background, a serverless setup like AWS Lambda with API Gateway works well, since it’s pay per invocation and cold starts of one to two seconds are rarely noticeable for background webhook processing. If instead your app has an admin UI that store staff will interact with regularly throughout the day, a container based option that stays consistently warm tends to perform better, since users interacting with a live interface will notice cold start delays in a way background processes never surface. For teams that want the simplest possible deployment experience, particularly during early development and testing, Heroku or Railway offer straightforward deployment at a higher per unit cost, which makes them reasonable for prototyping even if they’re less ideal once an app needs to scale. And if you scaffolded using the React Router or Remix-based template specifically, Vercel deployment tends to be close to zero config, which can be the fastest path to getting a working version live for internal testing.
Custom App Distribution And Access
One detail that trips up developers coming from a public-app mindset is that custom apps aren’t compatible with the same CLI driven distribution flow public apps use. Merchant custom apps are not compatible with the Shopify CLI in the same way, so you have to start your app directly rather than going through the standard CLI installation flow once it’s created inside the target store’s admin. After the app is created and configured in the store’s admin panel, you update your code with the API key, API secret key, and access token that Shopify generates specifically for that installation, and from that point forward your app authenticates directly against that one store rather than going through the broader OAuth installation flow a public app uses for each new merchant.
This is actually one of the genuine advantages of the custom app path. Since there’s no App Store review, no need to support arbitrary merchant configurations, and no multi-tenant session handling to worry about, the overall complexity of a custom app is meaningfully lower than a comparable public app, which means faster development time and fewer edge cases to account for.
Billing, If You’re Building For Multiple Merchants
If your project starts as a custom app but you later realize other merchants might want the same functionality, the path to converting it into a public app runs directly through Shopify’s Billing API. Revenue for a listed app typically comes through subscriptions handled via Shopify’s Billing API, whereas for a purely custom app serving one store, billing is handled directly between you and your client with no Shopify involvement at all. This is worth planning for early if there’s any chance your custom project might eventually go public, since retrofitting proper subscription billing onto an app that was never designed for multi-merchant use can require significant rework.
Working With A Developer Instead Of Building It Yourself
Not every store owner wants to become a Shopify app developer, and that’s a completely reasonable position. If your business needs a genuinely custom solution but you don’t have inhouse development resources, the process of scoping, building, and maintaining a custom app is exactly the kind of work worth handing off to a team that does this regularly. A good custom app starts with a clear conversation about the actual business problem, not the technology, since the specific framework and hosting choice should always follow from what the app needs to do, not the other way around.
Building For Pakistani Merchants And Local Integrations
Custom Shopify apps become especially valuable for merchants operating in Pakistan, since a lot of the local business logic simply isn’t covered by apps built primarily for Western or purely international audiences. A common example is building a custom order verification workflow that automatically flags cash on delivery orders for phone confirmation before they’re released to your courier, integrating directly with your existing WhatsApp Business setup so confirmation messages go out automatically rather than requiring manual follow up on every order.
Custom apps are also useful for connecting Shopify directly to courier APIs from providers like Leopards Courier, TCS, or M&P, so tracking numbers and delivery status sync automatically into your store rather than requiring manual entry for every shipment, which becomes genuinely unmanageable once your order volume grows past a certain point. For merchants accepting JazzCash or Easypaisa alongside standard card payments, a custom app can also help reconcile payment confirmations from those local gateways with your Shopify order data in a way that a generic international payments app usually won’t handle out of the box, since most public payment apps are built around card networks and international processors first.
Getting Your Custom App Off The Ground
Building a custom Shopify app is a meaningfully bigger undertaking than installing an app from the store, but for the right problem, it’s often the only path that actually fits how your business runs. Start by confirming an existing app genuinely can’t solve your problem, get comfortable with the core building blocks of the GraphQL Admin API, webhooks, App Bridge, and Polaris, choose a hosting setup that matches how your app will actually be used, and keep the scope focused on the specific business logic that made a custom build necessary in the first place.
