The Complete Shopify App Development Guide

A great Shopify app solves a real merchant problem and disappears into the admin. The fastest path to approval is to embrace the platform's conventions rather than fight them.

This guide covers the pieces reviewers actually check, and the integration points that trip up most first submissions.

Embedded apps run inside the Shopify admin via App Bridge, with UI built from Polaris components. Merchants get a consistent, trusted experience, and you inherit accessibility and responsiveness for free.

Use the Billing API for all charges; never collect payment outside Shopify. Verify the HMAC on webhooks and make handlers idempotent so retries don't double-process.

app.post('/webhooks', verifyHmac, async (req, res) => {
  await handle(req.headers['x-shopify-topic'], req.body);
  res.sendStatus(200); // ack fast, work async
});

• Build embedded with App Bridge and Polaris so your app feels native to the admin.
• Use the Billing API correctly — it's the most common review rejection.
• Handle webhooks idempotently and verify HMAC on every request.