Privacy Policy

Atmospheric messenger · Last updated: 8 September 2026

Atmospheric is a messaging application with end-to-end encrypted chats and calls. This policy explains what data the app handles, why, and what control you have over it. It is written to describe what the application actually does, not what it might do in the future.

The short version

Your messages are end-to-end encrypted. Our servers relay and store them only as ciphertext and cannot read them.
We do not sell or share your data with third parties for advertising or any other purpose.
The app contains no advertising and no analytics or tracking SDKs.
Your address book is never uploaded. Contact matching uses irreversible hashes that are not stored.
You can delete your account and all its data from inside the app.

What we collect and why

Data	Why	Where it is kept
Phone number	It is your account identifier. Sign-in is by phone number and a one-time SMS code.	On our server, for as long as the account exists.
Contact matching data	To show which of your contacts already use Atmospheric.	Not stored. See below.
Messages and attachments	To deliver them to the recipient and to let you sync a new device.	On our server as ciphertext only. See retention below.
Profile — display name, photo, username, "about" text	So people you talk to can recognise you.	On our server. Visible to other users of the app.
Public encryption key	So others can encrypt messages that only your device can open.	On our server. The matching private key never leaves your device.
Notification token	To wake your device when a message or call arrives.	On our server, replaced whenever it changes.
Call routing data — who is calling whom, and when	To ring the right device and to end calls that were not answered.	Held only for the duration of the call. Your call history is stored on your device.

Your contacts are not uploaded

To tell you which of your contacts use Atmospheric, the app would normally have to send us your address book. It does not.

Instead, the app computes an irreversible hash of each phone number on your device and sends only those hashes. The server compares them against hashes of registered users and returns the matches. The hashes you send are not written to any database — they exist only for the duration of that request. We hold no copy of your address book, and we cannot reconstruct one.

You can also stop other people from finding you this way, in the app's privacy settings.

End-to-end encryption

Message text and attachments are encrypted on your device before they are sent, and are decrypted only on the recipient's device. The private key used to do this is generated on your device and kept in the Android system keystore; it is never transmitted anywhere, including to us.

This has a consequence worth stating plainly: we cannot read your messages, and we cannot recover them for you. If you lose access to your device, message history encrypted for that device is gone.

What we can see is what any messaging service must see in order to deliver anything at all: that an encrypted message was sent from one account to another, and when.

Permissions the app asks for

Contacts — to match your contacts against registered users, as described above.
Camera and microphone — for calls, photos and voice messages. Used only while you are actively using those features.
Photos and files — to let you attach them to a message.
Location — only when you choose to send your location in a chat. The app does not track your location in the background.
Notifications — to tell you about new messages and incoming calls.

Service providers

Atmospheric runs on infrastructure operated by us and by Google:

Google Firebase — sign-in, database, encrypted file storage, push notifications and anti-abuse verification.
Our own servers — message relay and the media server used for voice and video calls.

These providers process data on our behalf in order to run the service. We do not use advertising networks, analytics services or crash-reporting services, and no such libraries are present in the application.

How long we keep things

Messages stay on our server, as ciphertext, until one of three things happens: you delete the message yourself (possible for up to 24 hours after sending), the disappearing-messages timer you chose runs out, or the account is deleted. Delivering a message does not by itself remove it — that is what lets a reinstalled or additional device catch up on a conversation.
Attachments are encrypted files kept in cloud storage. Deleting a message removes the message record; the file itself is removed by the device that uploaded it.
Account data — profile, phone number, keys — is kept while the account exists.
Deleted accounts are removed as described below.

Deleting your account

You can delete your account from inside the app, in the account settings. Deletion is scheduled rather than immediate, so that an accidental request can be cancelled; until the scheduled time you can cancel it from the same screen.

When deletion runs, we remove your account document, your messages, your encryption keys and your membership in every group. If you were the only administrator of a group, administration is passed to another member so that the group is not left ownerless; groups left with no members are deleted entirely.

Children

Atmospheric is not directed at children. The app is intended for people aged 18 and over, and we do not knowingly collect data from children.

Changes to this policy

If this policy changes in a way that affects what we collect or what we do with it, we will update this page and change the date at the top.

Contact

Questions about this policy, or about your data, can be sent to support@getatmospheric.com.