The Line is a mobile application that enables synchronous real-time text-based communication ("text phone calls") between users. This policy explains what personal data we collect, why, and how we handle it.
We collect your phone number to verify your identity via SMS, using Firebase Authentication (a service provided by Google). Your phone number is stored in our authentication database so we can identify you across sessions.
A normalised copy is kept in a private record that only you and our servers can read. It is never part of the record other users can see. So that someone who already has your number can reach you, we also keep a one-way hash (SHA-256) of it in a server-only index; when another user types a number, their device sends us only the hash, and we answer with a name and a username. Nobody can read your number back out of our directory, and no other user can obtain it from us.
Providing a phone number is optional. You can use The Line anonymously with a temporary handle instead; in that case we do not collect a phone number, and the handle is released when you leave.
With your permission, The Line reads the phone numbers in your device's contact list to identify which of your contacts are also registered on The Line. Contact phone numbers are one-way hashed (SHA-256) on your device before being transmitted to our servers. We do not store or receive contact names or raw phone numbers. The hashed values are compared against an index of registered hashed numbers, and matches are returned to your device.
If you choose a username, it is stored in our database associated with your account so other users can reach you by username. The display name shown on your line is stored alongside it.
Neither is browsable. There is no list of users to page through: another person reaches your record only by typing the start of your name or username, by typing a number that hashes to yours, or by using a pairing code you gave them. A successful lookup returns your display name, your username and the account id needed to place the call — and nothing else.
Messages sent during a live "line" session are transient. They are exchanged in real time via our backend and are not retained after the session ends.
So your phone can ring when the app is closed, we store a push notification token issued to your device by Apple or Google, together with the device identifier it belongs to and whether you have allowed notifications. The token identifies a device, not a person, and is replaced whenever the operating system reissues it.
Preferences that have to work across your devices — currently whether you have silenced incoming lines — are stored with your account.
When someone calls you, limited metadata (the caller's user id and a timestamp) is delivered to your device via Firebase Cloud Messaging so your phone can display the incoming-call notification.
When you look someone up, what you type is sent to our servers to be answered and is not stored. We do keep a per-account counter of how many lookups you have made in the last minute, and how many pairing codes you have tried recently, so that the search and pairing endpoints cannot be used to enumerate other people. Those counters hold numbers and timestamps, not what you searched for.
If you generate a pairing code so somebody in front of you can add you, we store a one-way hash of that code against your account for five minutes and then discard it. The code itself is never stored. Redeeming a code discloses the same three things a search does — display name, username, account id — and never a phone number.
If you block another user, their user id is stored in your personal block list on our server so the backend can refuse to route their incoming calls to you.
The Line uses the following Google / Firebase services:
Data sent to these services is subject to Google's privacy terms.
You may delete your account at any time from the app's Settings screen. Upon deletion, all data associated with your account is removed from our servers. For any other privacy-related request, contact uzi.menetzir@gmail.com.
The Line is not directed to children under 13.
We may update this policy from time to time. The effective date at the top of this page will reflect the latest version.
Questions: uzi.menetzir@gmail.com