Requirements & components

C3 control spans a hub, the hosts running agents, and one or more clients.

The hub machine (one, any machine you own)

The hub is a lightweight NATS relay. A Raspberry Pi, a home server, or a small VPS all work.

• The c3sync CLI — the hub is provisioned and run by c3sync hub commands, even if you never use C3Sync itself. Download the current public beta from the C3Sync release page and verify its checksum.

• Or C3 Desktop 0.1.3, which can download and verify C3Sync for the current machine and drive guided local or remote-SSH setup.

• Two reachable ports: 4222 (TLS 1.3, bridges and C3Sync) and 8443 (pinned WebSocket, phones). Reachable can mean your LAN, a VPN/overlay network, or the public internet — your choice.

Each controlled host (as many as you like)

Any machine whose agents you want to steer from the phone:

• Herdr 0.7.5+ — the terminal workspace manager that hosts your agents. Herdr is a separate project, installed separately (review its AGPL/commercial licensing); C3 never bundles it.

• C3 Bridge (c3bridge) — install the platform artifact through C3 Desktop, or download it from the C3 Bridge 0.1.1 release and verify SHA256SUMS-c3bridge-0.1.1.

• Your coding agents (Claude Code, Codex, …) running inside Herdr panes, as usual.

• Network access to the hub's port 4222.

Qualified bridge platforms in the current beta: Linux x64 and Linux ARM64. macOS and Windows binaries are built but still being qualified.

Your phone

• C3 Mobile 0.1.2 for Android, available from the public Android beta release. The APK is development-signed for the launch beta; verify its checksum. iOS qualification is deferred.
• A camera, for scanning enrollment and pairing QR codes.
• Network access to the hub's port 8443.

Your desktop (optional)

• C3 Desktop 0.1.3 on Linux, macOS, or Windows. It can replace most manual setup steps and enroll as another control client. Platform-specific Bridge limitations are listed above.
• The same network access to your hub and bridges described above.
• See the dedicated C3 Desktop requirements.

What talks to what

The phone and your machines never connect to each other directly — everything routes through your hub as ciphertext.

NOTE — > There is no C3 cloud. If your hub is off, the app can't reach your machines — and neither can anyone else.

Next: set up your hub.