Legal
CallVault Privacy Policy
A personal Android call recorder published by NEXUS-SECTECH LTD.
Last updated: 24 September 2026
The short version. CallVault runs entirely on your phone. It has no server, no account system, no analytics and no advertising. The only place it ever sends data is a folder in your own Google Drive, only if you switch that on, and only files it created itself. Nobody at NEXUS-SECTECH LTD can see your recordings.
What the app collects
CallVault records your phone calls and stores them on the device. To label a recording so you can find it again, it also reads information about the call itself.
| Data | Why | Where it goes |
|---|---|---|
| Call audio | The purpose of the app. Stored as an Opus .ogg file. |
Device storage; your Drive if backup is on |
| Phone number, call direction, time and duration | Read from the system call log so recordings can be named and searched | Device storage; your Drive if backup is on |
| Contact name | Matched from your contacts so a recording shows a name rather than a number | Device storage; your Drive if backup is on |
| Phone state | To know when a call starts and ends | Not stored |
| Call notifications posted by other apps | To know when a call inside another app starts and ends, and to take the name that app is displaying so the recording can be labelled. Only if you grant notification access; see below. | The displayed name is stored with the recording. Nothing else is kept. |
| Transcript text, if you ask for one | Produced from a recording by a speech model that runs on the device | Device storage only. Transcripts are not uploaded, including when backup is on. |
Every recording is saved with a .json sidecar file containing a SHA-256
hash of the audio, so you can prove a recording has not been altered. The sidecar holds
the same call details listed above.
Notification access, and how narrowly it is used
Recording a call made inside another app requires CallVault to notice that the call has started, and Android offers no other way for an app that is not running to be told. The app therefore asks for notification access. This is the most far reaching permission it requests, so what it does with it is set out precisely.
- Android shows every notification on the device to any app holding this permission. CallVault discards anything that is not an ongoing call notification, reading only the two markers needed to tell: what kind of notification it is, and whether it is ongoing. Nothing else is read from a notification it discards.
- One exception, and only while your phone is in a call inside an app (Android's communication audio mode): some apps, Telegram among them, do not mark their call notification as a call. To find which app the call is in, CallVault then looks at which apps have an ongoing notification and when it was posted. It reads nothing else from those notifications and keeps none of this once the call has been identified.
- From the one notification it takes to be the call, it reads one thing: the name being displayed for the caller. That name is stored with the recording, because a call inside another app carries no number and would otherwise be filed with nothing to identify it.
- Nothing from any other notification is stored, logged, transmitted, or used for any purpose. Message contents and senders are never read.
- The permission cannot be requested from inside the app. You grant it by hand in Android settings and can revoke it there at any time. If it is not granted, calls made inside other apps are simply not recorded, and nothing else changes.
Transcription happens on the device
If you choose to transcribe a recording, the speech model runs on the phone. The audio is not uploaded for transcription, no transcription service is contacted, and the feature works with the device offline. The resulting text stays in the app's own storage and is not included in Drive backup.
Diagnostics you choose to send
Settings contains an Export diagnostics action, for when something in the app misbehaves and whoever is helping you needs to know what your phone did.
It is not crash reporting and the app never sends it. Tapping it writes a file; you then choose whether to share it, and with whom, using whichever app you like. Nothing is transmitted by CallVault, and no destination beyond the Drive backup described above is ever contacted.
The file contains the app version, your phone's model and Android version, whether capture is currently working, your settings, and technical facts about your most recent recordings: how long they are, how large, which format, and what happens when this phone tries to decode them.
It deliberately leaves out phone numbers, contact names and recording filenames. Those are not collected into the file in the first place rather than removed afterwards. The one part assembled from the app's own running log is filtered before it is written. Your Google account address is never included; only whether backup is set up at all. It is plain text so that you can read the whole thing before deciding to send it, and you should.
What the app does not do
- No analytics, telemetry, crash reporting, advertising or tracking of any kind. No third-party SDKs for these purposes are present in the app.
- No user accounts, and no registration.
- No data is sold, shared, or disclosed to anyone.
- No server operated by NEXUS-SECTECH LTD receives your recordings or any other data. No such server exists.
Google Drive backup
Backup is optional and off until you choose a Google account in Settings.
When enabled, CallVault uploads your recordings and their sidecar files to a folder
named CallVault in the Google Drive of the account you chose. It requests one
OAuth scope:
https://www.googleapis.com/auth/drive.file
This is the narrowest Drive scope Google offers. It grants access only to files the app itself created. CallVault cannot see, read or modify any other file in your Drive, and it never requests broader access.
googleapis.com is the only internet destination the app contacts. Google's
handling of the files once they are in your Drive is governed by
Google's Privacy Policy.
CallVault's use of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
You can revoke access at any time from your Google Account permissions page, or by signing out in the app's Settings. Revoking stops future uploads; files already in your Drive remain there, under your control, and you can delete them yourself.
Retention and deletion
Recordings stay on the device until you delete them or a retention period you have set removes them. Deleting a recording in the app removes the audio and its sidecar from the device. Copies already uploaded to your Drive are not deleted automatically. Delete those in Drive if you want them gone.
Uninstalling the app removes its local storage, including all recordings held there.
Permissions the app requests
- Microphone: to capture call audio.
- Phone state: to detect when a call begins and ends.
- Call log: to determine the number and direction of the call just recorded.
- Contacts: to show a name instead of a number.
- Notifications: to show recording status, and to tell you when a call was not recorded.
- Notification access, optional and granted by hand in Android settings: to detect calls made inside other apps. Used only as described above. Without it, those calls are not recorded and nothing else is affected.
- Network access: only to upload to your Drive when backup is enabled.
Your responsibility when recording calls
The law on recording telephone calls differs by country and, in some places, by state or province. In some jurisdictions every party to the call must be told, or must consent, before it may be recorded. In others recording is permitted but using or sharing the recording is restricted.
CallVault records what you tell it to record. Ensuring that doing so is lawful where you are, and that anyone entitled to be informed has been, is your responsibility as the operator of the device.
Children
CallVault is not directed at children and is not intended for use by anyone under 16.
Changes to this policy
If this policy changes, the revised version will be posted at this address with an updated date above.
Contact
Questions about this policy or about the app: hello@nexus-sec.tech
NEXUS-SECTECH LTD, United Kingdom.