Your phone number is personal. Your contacts are too.

Local-first, by design

LineLayer is built around a local-first philosophy: call filtering decisions are designed to happen on your device, evaluated against rules you set — rather than depending on a large shared database of phone numbers that your calls get checked against remotely.

This is a deliberate design choice, not a claim that every possible feature will always work without any network activity. Where a specific feature does require something to leave your device, that should be clear from the feature itself.

Why LineLayer needs certain permissions

To filter calls at all, an app like LineLayer needs Android's phone and call-screening permissions, and to apply rules around your existing contacts, it needs access to your contacts. Those permissions are what make the core filtering rules — private-caller blocking, non-contact blocking, allow and block lists, country rules — possible.

Granting a permission gives an app technical access to that category of data. It doesn't by itself describe what the app does with it afterward — that depends on the app's actual practices. We think that distinction matters, which is part of why we're transparent about local-first processing being the design goal for LineLayer's filtering.

What LineLayer is not

LineLayer is not a global caller-ID lookup service, and it doesn't maintain or query a crowdsourced database of phone numbers to tell you who an unknown caller "really" is. It works from rules you define, not from identifying strangers.

The formal privacy policy

This page explains LineLayer's privacy philosophy in plain language. It is not a substitute for the app's full legal privacy policy, which covers the specific data handling practices required for Google Play and applicable law.

The complete legal privacy policy will be published here.