Flow action extensions now support relative paths for endpoint URLs
Shopify developer change
MerchantDiff detected this entry in Shopify's official developer changelog on June 18, 2026.
This Shopify update is categorized as Tools, Update.
What changed
You can now use relative paths for endpoint URLs in your Flow action extension configuration. The runtime_url, validation_url, config_page_url, and config_page_preview_url properties accept either an absolute HTTPS URL, such as https://example.com/api/flow/actions/place-bid, or a relative path that starts with a single /, such as /api/flow/actions/place-bid. When you use a relative path, Shopify CLI resolves it against your development tunnel URL while shopify app dev is running, and against your app’s application_url after you deploy. This means you no longer need to update your runtime_url each time your development tunnel URL changes, making it easier to point Flow actions at routes hosted by your own app. Use an absolute HTTPS URL when your endpoint is hosted on a different domain or service than your app, or when you want Flow to call the same URL in every environment.
Who is affected
Shopify app developers using the API or platform feature named in this update should review the official change.
What action may be needed
Review the official Shopify entry, confirm whether the change touches your app, and test the affected workflow before your next relevant deployment.
Use the official Shopify entry below as the source of truth for technical implementation details, affected APIs, migration instructions and deadlines.
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