A Shopify app handles other people's businesses, their orders, customers and revenue, so security is not optional polish, it is a duty. The good news is that most breaches come from a short list of avoidable mistakes. Here are the practices that keep apps and merchant data safe.
Protect access tokens
An access token is the keys to a merchant's store. Store tokens encrypted, never in code, logs or client-side, transmit them only over HTTPS, and rotate or revoke them when appropriate. A leaked token can expose an entire store, so token handling is the highest-priority control in any app.
Verify every webhook
Webhook endpoints are public, so anyone can hit them. Always verify the HMAC signature before acting, so you only process genuine Shopify events and not forged requests. Unverified webhook handling is a common and serious vulnerability, and verification is cheap. This is part of building reliable webhooks generally.
Request least-privilege scopes
Ask only for the API scopes your app genuinely needs. Over-broad access increases the blast radius if the app is compromised, and merchants (rightly) distrust apps requesting more than they should. Scope minimization is both a security control and a trust signal, and it is expected under Built for Shopify standards.
Validate input and guard against injection
Treat all input, from merchants, customers, and API responses, as untrusted. Validate and sanitize it to prevent injection and cross-site scripting, and use parameterized queries. The basics of application security apply just as much inside a Shopify app as anywhere else.
Handle data responsibly
Apps often touch customer personal data, which carries privacy obligations. Collect only what you need, secure it, honor data-deletion requests (Shopify's mandatory privacy webhooks exist for this), and be transparent about use. Responsible data handling is both a legal requirement and a reputation asset.
Keep dependencies and infrastructure current
Vulnerabilities often arrive through outdated libraries or misconfigured infrastructure. Keep dependencies patched, follow platform security guidance, and test before production. Security is ongoing maintenance, not a one-time checklist.
Secure apps protect merchants and earn the trust that Shopify's ecosystem runs on. It is a core part of professional app development.