FC21 Mobile

Communication with clear limits

FC21 is not a social messenger. It is organizational security infrastructure with a personal mode — zero-PII, invite-only, no ad tracking.

Core features

Direct messages

Personal 1:1 threads by default. Organizations are optional context — not the identity root.

ADR-0014

Connect

1:1 relationship requests by @handle or usr_ identifier. No friend matching, no address-book import.

ADR-0021

Groups and projects

Group threads with an optional topic. Welcome messages and bounded attachments in the development slice.

ADR-0017

View-once

Messages stay covered until you choose to open them, then they are consumed. No protection against screenshots or a compromised client.

ADR-0022

Pseudonymous conversations

A conversation-scoped presentation — not the global handle for the peer. Not cryptographic unlinkability.

ADR-0015

Device roster

Enrollment and revoke with confirmation. Devices belong to the user, not to the organization as the ownership root.

ADR-0014

Connect — named differently

Instead of “add friends”, FC21 uses Connect: an explicit request to a known account. Lookup is only by @handle or usr_… — never by email or phone number.

After acceptance, a lasting connection exists. Chat requests can go through Connect without a public directory.

ADR-0021 — Connect requests (1:1 relationship)

Invite-only discovery

The preferred way into a conversation is an opaque invite secret (fc21://connect/… or a grouped FC21-…). Random, expiring, revocable, stored only as a digest.

No random matching. No global people or organization directory to browse.

What we do not promise

No claim that you are anonymous, on the network or otherwise
No quantum-proof marketing without an external review
No production message-sealing implementation in this milestone
No voice or video as a public product claim in this milestone
No guarantee of APNs delivery without Apple credentials on the server

Product family

FC21 Mobile — Native iOS client — conversations, devices, settings

FC21 Control — Administration plane for organizations

FC21 Sovereign Node — Backend: relay, auth, entitlements

FC21 Core — Protocol core in Rust