Privacy Policy
Effective date: June 7, 2026
Tansen is a service for exchanging source-text cards between two smartphones so that the recipient can read them with browser translation. Tansen itself does not use a translation API and does not create or store translation results.
How Sent Text Is Handled
Tansen does not store conversation history. For each direction, it temporarily keeps only the latest card text needed for communication and display.
When a new card is sent in the same direction, the previous card text is replaced. When a session ends or expires, the latest card text is not retained.
Where Text Is and Is Not Returned
The normal state API and the initial WebSocket session_state return only metadata such as the latest card ID, direction, language, and creation time. They do not return the text body.
Text is handled only by the participant-to-participant WebSocket latest_card message and by the card display page used for Chrome translation.
The card display page returns text only after validating the participant token, participant slot, direction, and latest card ID. Card display page responses include headers intended to make browser or intermediary caching less likely and to make it less likely that the referring URL is sent externally.
Information Stored on the Device
Tansen stores the user's selected input language, participant slot, and participant token in the browser's localStorage for screen recovery and reconnection.
Sent text and received text are not stored in localStorage. If old pairing information remains, please create a new session.
Access Information
Tansen runs on Cloudflare Workers. Cloudflare may process IP addresses, access times, request information, and similar data for service delivery, security, and abuse prevention.
Providing Information to Third Parties
Tansen does not sell sent text or participant information.
Tansen does not provide sent text or participant information to third parties except when required by law, necessary to provide the service, or necessary to protect the service.
Contact
Please contact the operator of Tansen regarding this policy.