When do you need your own Shopify app?
Describe a specific bottleneck: which information is missing, what manual work follows and what happens when something fails? An app should improve an observable process. For example, matching Shopify orders to internal system records while reporting missing items.
Check existing settings, Shopify Flow and suitable App Store products first. Compare data coverage, edge cases, permissions, support and export options rather than feature names alone. Presentation-only changes may need only theme customisation.
Custom app or public app?
Custom distribution installs an app by link in one store or stores belonging to the same Plus organisation. Public distribution serves many merchants through the Shopify App Store. Choose before publication: the distribution method cannot subsequently be changed for the same app.
| Distribution | Typical use | Review and billing |
|---|---|---|
| Custom | One merchant or one Plus organisation | No App Store review; no Shopify Billing API |
| Public | An app product for multiple merchants | App Store review; Shopify billing available |
New apps use the Dev Dashboard in 2026
Since January 1, 2026, new custom apps can no longer be created directly in the Shopify admin. Use the Dev Dashboard instead. Existing admin-created custom apps continue to work, so older tutorials showing private-app creation describe an outdated creation process.
Distribution and authentication are separate choices. Embedded apps can use managed installation and token exchange; other apps use an appropriate authorisation flow. The client-credentials flow is for stores in the developer’s own organisation, not every agency client.
What determines development cost?
The number of systems and failure cases drives effort. A data export differs from two-way synchronisation involving inventory, partial fulfilment and refunds. Interface design, hosting, privacy and operational requirements add scope.
We define the core workflow before preparing a proposal, then specify data, permissions and acceptance tests. An MVP is the smallest useful working release rather than an unchecked demonstration. Additional functions can be planned separately.
| Cost driver | Planning question |
|---|---|
| Integrations | Which systems, APIs and access arrangements exist? |
| Processing | What volumes, edge cases and updates occur? |
| Interface | Who uses settings, status views and error lists? |
| Distribution | One merchant or multiple independent merchants? |
| Operation | Who handles hosting, monitoring and support? |
| Maintenance | How are API changes and new requirements managed? |
Define data ownership and failure handling first
For each field, specify which system is authoritative. If both ERP and Shopify can change stock, decide which update wins. Document what happens with deleted products, missing customer data and unavailable APIs.
Webhooks report events but do not replace a complete operational process. We plan incoming-message verification, duplicate-processing prevention, retries and reconciliation. Business cases such as partial fulfilment and refunds need separate tests.
For an ERP integration, provide example records and API documentation early. A successful happy path alone does not establish reliable operation.
Plan privacy and App Store review
Shopify checks public apps before publication. Requirements cover installation, permissions, usability and accurate listing information. Review is a separate project stage and its duration cannot be guaranteed.
Every App Store-distributed app must implement mandatory privacy webhooks for data requests and deletion, even if it collects no personal data itself. Hosting in Germany alone does not satisfy every privacy requirement. Review minimisation, access controls, deletion and required agreements.
From project brief to acceptance
Start with the desired workflow and examples of real edge cases. Follow with a concept, an early prototype and delivery in a test environment. Acceptance checks the agreed processes and visible handling of failures.
Accounting functions need clear responsibilities. An app must not inadvertently reissue invoices for historical orders or double-book refunds. Our products belegio and zrapp accounting integrations show the Shopify workflows we work on. The actual solution is defined for your business.
- Brief: describe the current process, target and examples.
- Design: define data model, authoritative systems and permissions.
- Build: implement the core workflow and relevant failures.
- Accept: test installation, outages, repeated events and edge cases.
- Roll out: agree production access, monitoring and fallback.
- Hand over: agree code access, documentation and operational responsibility.
What to send us for your app project
Send your store URL, connected systems and a short explanation of the desired workflow. Anonymised example orders, external API documentation and a description of the users are helpful.
Clarify whether this is an internal tool or a product for other merchants. Checkout requirements also need your Shopify plan because UI extensions and Functions have different prerequisites. See customising Shopify checkout.
