Privacy & Matching

Privacy belongs to you

Your contacts are read on your device. The address book is not uploaded. The matching happens between your phone and your shell — never between your phone and a stranger.

How matching works

When you import your contacts, the phone numbers and email addresses are turned into one-way fingerprints — hashes — on your device, before they leave it. MercyChain compares those fingerprints to the ones in its records. If a fingerprint matches, the person is already here, and a Shell badge appears on their row.

The plain phone number and email of someone you have not yet contacted stay on your device. The plain version is used only when you choose to send an invitation through WhatsApp — and it is sent through WhatsApp, not through MercyChain.

Country codes

A number that begins with + and a country code can be matched against any shell anywhere in the world. Without it, two friends in different countries might look like the same person. If a number is missing its code, MercyChain quietly asks which country the person is in, and adds it for you.

What you can see of others

Only what is public: their name, the address of their shell, and the actions you can take with them. Never their pearls.

Removing a contact

Inside a contact's detail you can edit it, remove the Shell match, or delete the whole entry. Deletion is final — for that contact's record on your shell. The other person's shell is not affected.