Shopify API Integration for ERP, 3PL, PIM and Back-Office Systems
Shopify API integration connects your store to the systems that run the rest of the business: the ERP that owns stock and pricing, the warehouse that ships orders, the PIM that holds product data, the CRM, the accounting package and the marketplaces you sell on. When those connections are missing or fragile, staff re-key orders, stock goes out of date, and nobody trusts the numbers. We choose and configure the right connector app where one fits, and build custom middleware on the Admin GraphQL API where it does not. You get data that moves on time, a written map of what syncs where, and alerts when something fails.
Integration projects are part of our Shopify store development service and are often scoped alongside a new build, a redesign or a Plus upgrade.
What an integration project covers
An integration defines which system is the source of truth for each type of data, how that data moves between Shopify and the other system, how often, and what happens when a sync fails. The deliverable is a working connection plus the documentation to maintain it.
Every project we run answers four questions before any code or app is chosen:
- Which system owns each field? Price might live in the ERP, descriptions in the PIM, stock in the warehouse system, and SEO fields in Shopify.
- Which direction does it flow? One way, both ways, or one way with exceptions.
- How fast does it need to arrive? Orders to a 3PL within minutes, product enrichment overnight, accounting daily.
- What happens on failure? Retry, alert, queue for review, or block the order.
Systems we connect to Shopify
| System | Examples | What usually syncs | Typical direction |
|---|---|---|---|
| ERP | NetSuite, Microsoft Dynamics 365 Business Central, SAP Business One, Odoo | Products, prices, stock, orders, customers, B2B terms | Both ways |
| PIM | Akeneo, Salsify, Plytix | Titles, descriptions, specs, images, variant options, metafields | PIM to Shopify |
| 3PL and WMS | Warehouse and fulfilment partners with an API or EDI | Fulfilment requests, tracking, stock levels, returns | Both ways |
| CRM | HubSpot, Salesforce | Customers, orders, lifetime value, B2B accounts | Shopify to CRM |
| POS | Shopify POS, third-party in-store systems | Stock by location, in-store sales, customers | Both ways |
| Accounting | Xero, QuickBooks | Orders, refunds, payouts, fees, tax | Shopify to accounting |
| Marketplaces | Amazon, eBay and others via Marketplace Connect or a dedicated connector | Listings, stock, orders | Both ways |
Brand names above are examples of systems stores commonly run. We scope each integration against the specific system and version you use.
Connector app, integration platform or custom middleware
There are three ways to connect Shopify to another system, and the cheapest one to build is not always the cheapest one to run.
| Option | Good for | Watch out for |
|---|---|---|
| Connector app from the Shopify App Store | Common systems with standard data, fast setup | Fixed field mappings, limited error visibility, monthly app fees |
| Integration platform (iPaaS) | Several systems, moderate customisation, in-house ops team | Platform licence cost, logic spread across many flows |
| Custom middleware on the Admin GraphQL API | Unusual data models, high order volumes, strict timing, legacy systems | Needs hosting, monitoring and an owner |
We start by testing whether a connector covers your real data. If it maps nearly all of your fields and the gaps can be handled in metafields or a small extension, that is usually the right answer. When a connector would force you to change how the business works, we build custom.
How we build custom Shopify integrations
Custom integrations run as a custom app installed only on your store, with access scopes limited to what the integration needs. The technical choices below are where most fragile integrations go wrong.
Admin GraphQL API first
Shopify now treats the REST Admin API as legacy and puts new capability into the Admin GraphQL API. We build on GraphQL so the integration does not need rewriting when older endpoints are retired, and so we can request exactly the fields we need in one call.
Webhooks with verification and reconciliation
Webhooks tell the middleware the moment an order is created, a product changes or stock moves at a location. They can be delivered to an HTTPS endpoint, Amazon EventBridge or Google Cloud Pub/Sub. We verify each webhook's HMAC signature, process events idempotently because the same event can arrive more than once, and do not rely on arrival order. A scheduled reconciliation job compares both systems and repairs anything a missed webhook left behind.
Bulk operations for large data sets
Initial loads and nightly catalogue syncs use bulk operations rather than thousands of paged calls. A bulk query exports products, variants or orders to a JSONL file that the middleware processes. Bulk mutations import changes from a staged upload. This keeps large catalogues in sync without hitting rate limits.
Rate limits and throttling
The GraphQL Admin API limits apps by calculated query cost, not request count, and Shopify Plus stores get higher limits. The middleware reads the throttle status returned with each response, backs off before it is blocked, and queues work during flash sales so orders still reach the warehouse in order.
Data mapping
Most sync errors are mapping errors. We document how Shopify objects relate to the other system:
- SKU as the shared key, with Shopify variant IDs and inventory item IDs stored against ERP item codes.
- External IDs stored in metafields, so records can be matched without guessing.
- Locations mapped to warehouses, with fulfillment orders routed to the right 3PL.
- Discounts, shipping, taxes, refunds and Shopify Payments fees mapped so accounting totals match payouts.
- Currencies and prices per market when Shopify Markets is in use.
Sync monitoring
Every integration ships with logging, retries, a queue for failed records, and alerts to a named person by email or Slack. You can see what synced, what failed and why, without asking a developer.
Problems we fix
| Problem | Usual cause | Fix | Metric it moves |
|---|---|---|---|
| Overselling items that are out of stock | Stock syncs on a slow schedule or ignores some locations | Event-driven stock updates plus reconciliation | Oversell and cancellation rate |
| Orders not reaching the warehouse | Silent API failures, no retry | Queue with retries and alerts | Order-to-ship time |
| Duplicate customers in ERP or CRM | No shared key, email changes | Matching rules and stored external IDs | Data quality, support time |
| Accounting never reconciles | Refunds, discounts and fees mapped inconsistently | Explicit financial mapping by transaction type | Month-end close time |
| PIM overwrites SEO titles and descriptions | PIM set as owner of every field | Field-level ownership rules | Search visibility of edited pages |
| Integration stalls during a sale | Rate limits hit, no backoff | Cost-aware throttling and queueing | Orders processed per hour at peak |
A PIM or ERP that creates or renames products can also change handles, create near-duplicate products or push thin content to live URLs. When that happens, our technical SEO for Shopify team checks redirects, canonicals and indexation so the sync does not quietly cost you search traffic.
Where integration stops and automation starts
Integration moves data between Shopify and another system. Automation decides what to do with it on a schedule or rule. We keep them separate so each has a clear owner:
- Rules for stock thresholds, auto-hiding sold-out products and reorder triggers belong to stock and inventory automation.
- Tagging, routing and exception handling after an order lands sit with our order workflow automation service.
- Scheduled jobs, bulk price updates and custom reports built directly on the API are covered by custom-coded API automation.
- Storefront features, such as a configurator reading live ERP data, are bespoke Shopify app development.
Integrations on Shopify Plus
Plus stores tend to have more systems, more locations and more order volume. Higher API limits help, and B2B adds data that must come from the ERP: company records, catalogs, price lists and payment terms. Setting up B2B, expansion stores and checkout logic on Plus is handled by our Shopify Plus developers, and we connect those features to your back office.
How an integration project runs
- Audit and baseline. We map your current systems, data owners, manual re-keying and existing apps, and measure where time and errors go today. You receive a written integration audit.
- Strategy and scope. We produce a data mapping document and recommend connector, iPaaS or custom build. You agree a fixed scope and timeline.
- Build and fix. The integration is built against a development store or a sandbox of the other system first. You review test orders, product syncs and failure alerts before anything connects to live data.
- Launch and track. We switch the integration on in a planned window, watch the first live syncs closely, and hand over documentation. Ongoing clients get a private portal, monthly reporting and a monthly call.
Cost and timeline
Integration work is a fixed project fee, scoped after a discovery call, because a connector configuration and a two-way ERP build with B2B pricing are very different amounts of work. See how quotes are put together on our pricing page.
As a typical range, a connector setup takes one to three weeks and a custom ERP or 3PL integration takes six to twelve weeks. Timing depends on data quality, how many systems are involved, and access to the other system's API and test environment.
If you already know which system you need connected, book a Shopify integration scoping call and bring a sample of your data.
Who this service is for
- Stores re-keying orders into an ERP, warehouse or accounting system by hand.
- Brands moving to a new ERP, PIM or 3PL and needing Shopify connected on day one.
- Stores whose current connector drops orders or stock updates without telling anyone.
- Multi-location and wholesale brands that need stock and prices from one source of truth.
Frequently asked questions
Often an app will do. We test your real data against available connectors first and only recommend custom middleware when a connector cannot handle your data model, volume or timing.
A custom ERP integration usually takes six to twelve weeks, depending on data quality and access to the ERP's API. A connector setup is much faster.
It is a fixed project fee quoted after a discovery call. The price depends on the number of systems, the direction of sync, data volume and whether a connector or custom build fits.
Failed records go to a queue, are retried automatically, and trigger an alert to a named person if they keep failing. A reconciliation job also compares systems on a schedule.
We build on the Admin GraphQL API, which is where Shopify adds new capability. It also lets us use bulk operations and cost-based throttling for large catalogues.
Yes. We sync companies, locations, catalogs, price lists and payment terms from the ERP so trade buyers see the right prices when they log in.
A staff account on Shopify with the right permissions, plus API credentials or a sandbox for the other system. Integration apps request only the access scopes they use.
Related services
- Shopify API automationscheduled jobs and bulk updates that run on top of your integrations.
- Automated stock updates across locationsrules that act on the stock data your ERP or WMS sends.
- Order routing and fulfilment automationwhat happens to orders after they reach your 3PL.
- Custom app development for Shopifystorefront and admin features that use integrated data.
- B2B and multi-store builds on Plusthe Plus features your back office often needs to feed.
- Shopify operations automationthe rules and workflows that act on data once your systems are connected.
Scope your Shopify integration
Tell us which systems you run and where data gets stuck today. We start with a free audit of your current setup and send back a data mapping outline with a recommended approach. Scope your Shopify integration with us.