Privacy Policy

Last updated: 2026-05-25

This privacy policy describes how Wuxi Guiwansu ("we", "us", "our") handles information processed by our Shopify application, Invoice Calculator (the "App"). The App is offered as a business-to-business tool to merchants who install it on their Shopify store to generate supplier invoices.

1. Who this policy applies to

This policy applies to Shopify merchants who install the App on their store and to the end-customer order data the App processes on the merchant's behalf. It does not apply to Shopify itself; Shopify's own data handling is governed by Shopify's privacy policy.

2. What data the App processes

When a merchant installs the App and connects their store, the App may access:

• Shopify order data — order numbers, dates, line items, product titles, SKUs, quantities, prices, shipping addresses (country and region only used for pricing lookup), fulfillment tracking numbers and carriers.
• Shopify product data — product titles and primary images, used to display product photos in the generated invoice output.
• Merchant configuration — store domain, Google Sheet identifiers the merchant provides, supplier-side discount settings, and an OAuth access token returned by Shopify (encrypted at rest using AES-256-GCM before storage).

The App does not persistently store individual customer names, email addresses, phone numbers, payment information, or full shipping addresses. Order data is read on demand when generating an invoice and is not retained as a long-lived copy in our database after the invoice run completes.

3. How the data is used

The App uses the data exclusively to generate supplier invoices for the merchant who installed it. Generated invoice output is written to a Google Sheet that the merchant controls and shares with the App's service account. We do not use the data for advertising, analytics outside of basic error monitoring, profiling, automated decision making, or any purpose beyond invoice generation.

4. Where the data is stored

• PostgreSQL database hosted on Railway. Stores merchant configuration, encrypted Shopify access tokens, and invoice run history (date ranges and row counts only — no customer PII).
• Google Drive (via a Google Cloud service account) — stores composite product-image files referenced by the merchant's invoice sheet. These files are publicly linkable but contain only product photos sourced from the merchant's own Shopify store.
• The merchant's own Google Sheet — the invoice output is written to a sheet the merchant explicitly designates and controls. We do not retain a separate copy.

5. Third parties we use

• Shopify — to read order and product data via the merchant-granted OAuth token.
• Railway — application and database hosting.
• Google Cloud Platform (Sheets API, Drive API) — to write invoice output to the merchant's Sheet and to host product-image composites.

We do not sell, rent, or share data with any party for advertising or marketing purposes.

6. Data retention

Invoice run history (dates, row counts, output tab name) is retained for as long as the merchant uses the App, so the merchant can audit prior runs. Encrypted access tokens are retained until the merchant uninstalls the App or revokes access. Composite image files in Google Drive are retained as a cache for performance and are eligible for periodic cleanup.

7. Merchant and customer rights

The App responds to Shopify's standard GDPR webhooks:

• customers/data_request — the App does not store individual customer data, so no data is returned.
• customers/redact — no individual customer data is stored, so no action is needed.
• shop/redact — when Shopify sends this webhook (typically 48 hours after a merchant uninstalls), the App permanently deletes the merchant's configuration row and all associated invoice run history from its database.

If you are a merchant and you wish to request deletion of your data outside of these webhooks, contact us at the address below.

8. Security

All data in transit is protected by HTTPS. Shopify access tokens are encrypted at rest using AES-256-GCM with a server-only key. The application runs behind Railway's standard production infrastructure. We do not log raw order payloads to persistent storage.

9. International data transfer

Wuxi Guiwansu is based in China. The App is hosted on Railway (United States infrastructure), and the App interacts with Google Cloud services. By installing and using the App, the merchant acknowledges that data may be transferred across international borders for processing as described in this policy.

10. Children's data

The App is a business tool intended for use by merchants and their suppliers. It is not directed to children, and we do not knowingly collect any data from children.

11. Changes to this policy

We may update this policy from time to time to reflect changes to the App or to legal requirements. The "Last updated" date at the top of this page reflects the most recent revision.

12. Contact

For privacy questions, data requests, or any other inquiries about this policy or the App, contact us at calculatorinvoice@gmail.com.