Privacy
What we collect — and what we don't.
Mercurius is built to teach AI literacy. Pretending you can't see how a product handles your data would be dishonest on both counts. So: the full picture, in plain language.
Last updated: May 2026 · Subject to change as the product evolves.
What we collect
A random session ID. When you open the app for the first time, Mercurius generates a 32-character random identifier and stores it in the iOS Keychain on your device. The server sees this ID on every request so it can recognize you across sessions for features like streaks and conversation memory. It is not tied to your name, email, phone number, or any external identity.
Your chat messages. Every message you send is sent to our server (hosted on Railway) and forwarded to Anthropic's Claude API to generate a response. The messages are also stored on our server, keyed by your session ID, so Mercurius can remember the conversation across launches.
Anonymous usage signals. Standard server logs capture the time and outcome of each request (e.g. "chat request succeeded"). They do not include message content, your IP address in clear form, or any personal information.
What we don't collect
- No name, email, phone number, or address. Mercurius doesn't ask for an account and doesn't have one.
- No demographic data. No age, gender, ethnicity, location, or school affiliation.
- No third-party tracking. No Google Analytics, no Facebook Pixel, no advertising SDKs. None.
- No ad targeting. Your chat history is not used to sell anything to anyone.
- No device fingerprinting. The session ID is randomly generated, not derived from your device.
Who sees what
To generate replies, Mercurius sends your messages to two third parties:
- Anthropic (anthropic.com) — runs the Claude language model that produces the actual answers. Their data policies are at anthropic.com/legal. Anthropic does not train future models on API requests by default.
- Railway (railway.app) — hosts our backend server. Standard hosting provider; sees the encrypted HTTPS traffic and the database that stores conversations.
We do not share, sell, or transfer your messages to anyone else.
Your controls
- Start Over. The Settings sheet inside the app has a "Start Over" button. Tapping it clears your local chat history, wipes your session ID from the Keychain, and generates a fresh one. From the server's perspective you become a brand-new user.
- Delete the app. Removing Mercurius from your device clears local chat history. Server-side conversation data keyed to your old session ID becomes unreachable from your device.
- Email us for full deletion. If you want server- side data tied to your session ID permanently deleted, email the address below with your session ID (visible in the app's Settings sheet). We'll process the deletion within 30 days.
Contact
For privacy questions or data-deletion requests: privacy@trymercurius.com
For everything else, the marketing site's main pages cover what Mercurius is and what it isn't.