Privacy policy

What we collect

• Account: your email address, a display name, and your password (stored only as a secure hash by our sign-in provider).
• What you add: trips (destinations, dates, travellers, budget, notes), itineraries, expenses, bookings, saved places, visa and document checklists, and your chats with the AI planner.
• Preferences: language, home currency, home city and airport, temperature unit, travel style, hotel preferences and passport country, if you set them.
• Sharing: who you invited to a trip and their role.
• AI usage: how many AI tokens you used each day, so we can apply the daily allowance.
• Technical: the sign-in and language cookies needed for the app to work, and standard server logs (such as IP address and time of request) kept by our hosting providers for security.

How we use it

• To run the app: show your trips, keep them in sync between devices and with people you share them with.
• To answer AI requests you make, only after you have allowed AI features (see below).
• To keep the service secure and to apply fair-use limits.

We don't use your data for advertising or profiling, and we don't sell or rent it.

AI features

The trip planner, hotel and food suggestions, visa checks and attraction research use Google Gemini or Anthropic Claude. Before your first use, Lang Thang asks for your permission. When you use these features we send only what the answer needs: your messages to the planner, trip details (destination, dates, travellers, budget, planned activities) and relevant preferences (travel style, hotel preferences, home city or airport, passport country). We never send your name, email address or password.

Google and Anthropic process this data under their own API terms and privacy policies. You can turn AI features off at any time under Account → AI features; nothing further is sent after that.

Services that help us run Lang Thang

• Supabase: database and sign-in (stores your account and trip data).
• Google and Apple: only if you choose "Continue with Google" or "Continue with Apple". They confirm who you are and share your name and email address (Apple may share a private relay address instead); we never see your Google or Apple password.
• Vercel: hosting of the app.
• Google (Gemini API) and Anthropic (Claude API): AI features, only with your permission.
• Open-Meteo: weather forecasts (receives the coordinates of your destination).
• Photon (Komoot) and Overpass (OpenStreetMap): place search and map pins (receive the place names you search for).
• Wikipedia: destination descriptions (receives the destination name).
• Xotelo: hotel price comparison (receives hotel and destination names).
• Exchange rate providers: currency conversion (no personal data).
• Booking links (for example Booking.com, Skyscanner, GetYourGuide) open those sites only when you tap them; their own privacy policies apply there. Some links carry our partner ID so the site can credit us for a booking; it doesn't identify you.

Each of these receives only what it needs for its task and is expected to protect it at least as well as described here.

Sharing with other people

If you invite someone to a trip, they can see that trip (and edit it if you made them an editor), including its itinerary, expenses, bookings and the names of the people on it. Nothing else in your account is shared.

How long we keep data, and deleting it

We keep your data while you have an account. You can delete individual trips, chats and entries at any time, and you can delete your whole account under Account → Delete account. This permanently removes your account and everything in it straight away; backups kept by our database provider are overwritten within their normal backup cycle. Trips other people shared with you stay with their owners.

Some data is kept in your browser only (for example the trip cost estimate and dismissed tips); clearing your browser data removes it.

Your rights

You can see and change your data in the app, export trips (print or calendar file), withdraw AI consent, and delete your account. Depending on where you live you may have further rights, such as asking for a copy of your data; contact us to use them.

Children

Lang Thang isn't meant for children under 13, and we don't knowingly collect their data.

Changes

If we change this policy we'll update the date above, and tell you in the app if the change is significant.