Privacy Policy

What we collect

• Location — your approximate GPS coordinates, only after you grant permission, and only to answer a query such as “buses near me”.
• Messages — what you type in the chat, plus the transit data returned for it (stops, routes, arrival times).
• Technical data — your IP address and standard request metadata, seen by our servers when the app makes a request.
• Preferences — your chosen language.

How we use it

• To find nearby stops, routes, and real-time arrivals for your query.
• To generate the assistant's replies and decide which transit tools to call.
• To classify whether a message is a Hong Kong transport question, so off-topic requests are declined.
• To rate-limit abusive traffic, using a short-lived record keyed to your IP address.

Where your data is stored

Your conversation history lives on your own device — in your browser's local storage on the web, and in a local database on the mobile app. It is not stored on our servers, and it never leaves your device except as part of the request you send.

Messages sent to us are processed in memory to produce a reply. A streaming response may be held briefly in a temporary cache (up to 5 minutes) so a reconnecting client can resume it. Server logs containing request metadata are retained for a short period for reliability and abuse prevention.

Clearing your data

Tapping “New chat” deletes the stored conversation from your device. Clearing your browser's site data, or uninstalling the mobile app, removes everything held locally.

You can revoke location permission at any time in your browser or device settings. The assistant will still work, but you will need to name a place instead of using your current position.

Who else processes your data

We rely on a small number of service providers to run the app. They receive only what is needed to perform their function:

• Vercel — hosting and serving the app.
• Vercel AI Gateway and the underlying AI model provider — receives your messages and location coordinates to generate a reply.
• Mapbox — serves map tiles and styles when a map is displayed.
• Upstash — temporary cache for resumable response streams and rate limiting.
• Hong Kong transit data sources (including KMB and Citybus open data) and OpenStreetMap Nominatim for place lookup — receive stop, route, or place queries derived from your request.

Children

This service is not directed at children under 13, and we do not knowingly collect their personal data.

Your rights

Because we do not hold accounts or conversation history on our servers, most of your data is already under your direct control on your device. For any other request regarding data we hold, contact us and we will respond as required by applicable Hong Kong law, including the Personal Data (Privacy) Ordinance.

Changes to this policy

If this policy changes materially, we will update the date at the top of this page.

Contact

Questions about privacy? Email privacy@rxlab.dev.