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Team messaging
uChat is an end-to-end encrypted messenger for one-to-one and group conversations, with text, voice messages, file attachments, replies, emoji, bookmarks and auto-translate — the everyday flow of team chat.
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Alternative
UltimaOS as a Slack alternative
Slack keeps a readable copy of every message. UltimaOS keeps ciphertext it cannot open.
Slack stores your team's messages on its US servers in a form it can read, index and retain. UltimaOS gives you the same real-time team communication — encrypted chat, group conversations, voice messages, file sharing and calls — through uChat and uMeet, inside a web operating system that is end-to-end encrypted and hosted in the EU.
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Overview
What replaces Slack inside UltimaOS.
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Calls and huddles
uMeet adds peer-to-peer calling: audio-only or video, instant or scheduled meetings, with picture-in-picture for one-to-one calls — covering Slack huddles and calls.
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Files where you talk
Attachments in uChat are objects in the same encrypted file system as uFiles, so sharing a file in a conversation does not copy it into a separate silo.
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Details
Where the real difference is.
Both give teams real-time chat and calls. The difference is whether a readable copy of everything you say sits on the provider's servers.
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Who can read your messages
Slack stores messages on its servers in a form it can read, index and retain under workspace policy. uChat encrypts every message end-to-end on the device; the server holds only ciphertext and has no key, so the operating system cannot read your conversations.
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Where your conversations live
Slack runs on US infrastructure under US jurisdiction, reachable under the CLOUD Act. UltimaOS runs on EU infrastructure under EU jurisdiction — GDPR-aligned by architecture, with no transatlantic transfer.
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Calls without a server in the middle
uMeet uses a peer-to-peer mesh for call media, so audio and video flow directly between participants rather than through a provider that could record them.
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No retention you do not control
There is no readable message archive on the provider side to be searched, subpoenaed or breached — because the provider never holds plaintext.
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Key points
What you keep, what you gain.
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You keep team communication
Group chat, direct messages, voice notes, file sharing and calls are all present — the daily rhythm of a team, intact.
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You gain end-to-end encryption
Messages are encrypted to their recipients on the device; the provider stores ciphertext it cannot open.
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You gain EU sovereignty
EU hosting and EU jurisdiction by default, not an enterprise-tier promise layered on a US service.
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References
Standards and references.
- US CLOUD Act (Congress) ↗ www.congress.gov
- GDPR — official regulation text (EUR-Lex) ↗ eur-lex.europa.eu
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Frequently asked
UltimaOS as a Slack alternative — common questions
Is UltimaOS an end-to-end encrypted Slack alternative?
Short answer
Yes. uChat provides end-to-end encrypted one-to-one and group messaging with voice notes, attachments and replies, and uMeet adds peer-to-peer calls — all inside an EU-hosted web operating system, with no readable message store on the server.
Can the provider read our team messages?
Short answer
No. uChat encrypts messages end-to-end on the device, with the server holding only ciphertext and no key. Slack, by contrast, stores messages in a form it can read, index and retain.
Does it support group channels and calls?
Short answer
Yes. uChat handles group conversations with replies, emoji, bookmarks and auto-translate, and uMeet handles audio and video calls, instant or scheduled, over a peer-to-peer mesh.
Where are our conversations hosted?
Short answer
On EU infrastructure under EU jurisdiction, with no transatlantic transfer. GDPR alignment is a property of the architecture.
Is UltimaOS only a Slack replacement?
Short answer
No — team chat and calls are two of its apps. UltimaOS is a full web operating system that also includes encrypted mail, files, documents, spreadsheets, calendar, contacts and AI.