One app.
Many sovereign systems.
Souverain is not one network — it is any number of them. Every organisation runs its own complete messenger backend in an environment it controls, with its own members, its own rules and its own jurisdiction. The member sees all of it as a single contact list on one phone.
Android · iOS · macOS · Windows · European development, designed for safety and personal data protection.
A complete messenger, on your terms
Everything your members expect from a modern messenger — delivered from a backend that you own, operate and control.
Fully customisable
Source code available. Adapt the apps and the backend to your organisation's identity and processes.
Identity protection
No e-mail address, no phone number. A member is a random 128-bit identity plus a self-chosen name.
Runs in your own environment
On-premise, in a national datacenter or in an EU cloud region — the operator holds all the data.
Multiple systems combined
A large user base can be split into divisions, each running its own messenger system. The app connects to one or many divisions in a single view.
Android · iOS · macOS · Windows
Native apps for phones and desktops. The complete experience works identically against every system.
GDPR-compliant
Full user data control. The organisation is both controller and host — data never leaves its environment.
No user passwords
Nothing to forget, nothing to phish. Device-bound identities replace the password altogether.
Full messenger functionality
1:1 and group chat, audio and video calls, media, reply and forward, edit and delete.
Control over exposure
Settings let every member decide how visible they are — and two operation modes: customer-friendly and advanced.
Nearby contact via Bluetooth
Meet members who are physically nearby — no internet needed. Contacts grow by meeting people, not by uploading address books.
End-to-end encrypted
1:1 messages are end-to-end encrypted between the members' devices. Each backend runs entirely inside your perimeter, so there is no third-party relay in the path.
Sovereign by deployment
The backend is a single deployable service. It runs where the organisation decides — and that operator answers to nobody else.
Four private worlds, one contact list
Each system below is a fully independent messenger deployment — separate servers, separate member registry, separate policies. The app registers with each system under a different random identity and merges what it sees, on the device.
Central government
- runs in a state datacenter
- own servers
- own member registry
- own security policy
Board of directors
- runs in the corporate private cloud
- own servers
- own member registry
- own retention rules
National railways
- runs in an EU cloud region
- own servers
- own member registry
- own moderation team
Restaurant chain
- runs on regional franchise hosting
- own servers
- own member registry
- own community rules
The colour of each contact's dot is the system that vouches for them. Merging happens on the device — no central directory, no super-server, no cross-system database ever exists.
No links between systems
Every system talks only to the app of its own members, over TLS, inside or into its own perimeter. Systems never exchange data with each other — a breach, subpoena or policy change in one world cannot touch another.
Sovereignty as a property, not a promise
Four design decisions carry the whole model.
No personal identifiers
Joining a system needs no phone number, no e-mail, no address book. A member is a random 128-bit identity plus a self-chosen name — different in every system.
Sovereign by deployment
The backend is a single deployable service. It runs where the organisation decides — on-premise, a national datacenter, an EU cloud — and that operator holds all the data.
Isolated by design
Systems share no infrastructure, no directory, no accounts. The only place they meet is the member's own device, which merges the contact lists locally.
One full experience
Chat, voice and video calls, groups, media, and Bluetooth nearby discovery — the complete app works identically against every system.
Souverain next to the big three
Compared on the axes that matter to a privacy- or sovereignty-driven organisation: what a member must hand over, where the data lives, and who the operator answers to.
| Criterion | Souverain | Signal | Telegram | |
|---|---|---|---|---|
| Identity & personal data | ||||
| Sign-up requires | ✓Nothing personal — random code + chosen name | ✗Phone number | ✗Phone number | ✗Phone number |
| Phone / e-mail exposed to contacts | ✓Never — neither exists in the system | ✗Number visible to chat partners | ~Hidden if you set a username | ~Hidden if you set a username |
| Address-book upload | ✓Never — contacts grow by meeting people | ✗Contacts uploaded to Meta | ✓Private hashed discovery | ~Optional; stored in Telegram's cloud |
| Sovereignty & compliance | ||||
| Where the data lives | ✓Your own servers, your own perimeter | ✗Meta datacenters | ✗Signal's US cloud infrastructure | ✗Telegram's distributed cloud |
| US jurisdiction (CLOUD Act) | ✓Outside — EU vendor, operator-run infrastructure | ✗Subject — US company | ✗Subject — US foundation | ~Outside, but opaque (Dubai / BVI) |
| GDPR position | ✓The organisation is controller and host — data never leaves its environment | ~Compliant on paper; data processed by Meta in the US | ~US entity; holds almost no data to regulate | ✗Cloud chats stored by an operator outside EU oversight |
| Self-hosted / private deployment | ✓Yes — one deployment per organisation | ✗No | ✗No hosted alternative | ✗No |
| Parallel systems in one app | ✓Yes — any number, merged into one list on the device | ✗One network | ✗One network | ✗One network |
| Security & metadata | ||||
| Encryption | ✓End-to-end by default | ✓End-to-end by default | ✓End-to-end by default | ~End-to-end only in "secret chats"; never for groups |
| Who holds the metadata | ✓The operating organisation itself | ✗Meta — extensive, ad-linked | ✓Almost none retained | ✗Telegram's cloud |
| Product & incentives | ||||
| Offline nearby discovery | ✓Yes — Bluetooth "Nearby", no internet needed | ✗No | ✗No | ~"People Nearby" via location, online only |
| Funded by | ✓Operator licences — the customer is the client | ✗Meta's advertising ecosystem | ✓Donations | ~Ads + Premium subscriptions |
Organisations named in the systems diagram are illustrative examples of the deployment model, not customers or endorsements.
Competitor characteristics are drawn from publicly available documentation and policies as of August 2026 and may change.
1:1 messages are end-to-end encrypted between the members' devices; in addition, each backend runs entirely inside the operating organisation's own perimeter, so there is no third-party relay in the path.
Full test version available on request
See Souverain running against your own environment. We set up a test system, you install the apps, and your team tries the complete messenger — chat, calls, groups and nearby discovery.
Or call Marc van Oldenborgh at +31 6 51459 459