Mahjong Lens

Privacy Policy

Last updated: April 3, 2026

What we collect

Mahjong Lens is designed to collect as little data as possible.

• Photos: When you use the AI analysis feature, your photo is sent to our server to be analyzed by Claude (Anthropic's AI). Photos are not stored — they are processed and immediately discarded.
• Anonymous device ID: A random identifier is generated on your device to track your free usage quota and purchase status. It is never linked to your name, Apple ID, or any personal information.
• Game data: Player names, chip counts, and round history are stored locally on your device only. We never have access to this data.

What we do not collect

• Your name, email, or Apple ID
• Location data
• Analytics or crash reporting
• Any data sold or shared with third parties for advertising

Camera

Camera access is used solely to photograph mahjong hands for AI tile counting. The app does not access your photo library and does not save photos taken within the app.

In-App Purchases

Purchases are processed entirely by Apple. We do not store your payment information. Purchase status is verified via Apple's StoreKit and recorded against your anonymous device ID.

Third-party services

• Anthropic (Claude AI): Photo data is sent to Anthropic's API for analysis. See Anthropic's Privacy Policy.
• Cloudflare Workers: Our server runs on Cloudflare's infrastructure. See Cloudflare's Privacy Policy.

Data retention

Your anonymous usage quota and purchase status are stored on our server for as long as you use the app. You can request deletion at any time by contacting us.

Children

Mahjong Lens is not directed at children under 13 and we do not knowingly collect data from them.

Changes

We may update this policy. Continued use of the app after changes constitutes acceptance of the updated policy.