Interactive terminal attach

Attach an interactive terminal to another joined machine’s already-running agent. It is not SSH: the target needs a running Cmdop agent, not an SSH daemon, and no inbound port has to be open on it — the machine dialed out to the relay, so nothing has to dial in.

cmdop connect <machine>

To choose from a list instead of naming a machine:

cmdop connect            # picker: other machines, online only
cmdop connect --all      # include offline machines and this one
cmdop connect --list     # just print the roster

The picker deliberately hides this machine, offline machines, and the fleet orchestrator — see Machines if something you expected is missing.

What it requires

Three things, in order:

1. The target is online. Its agent must be connected to the relay.
2. The target is reachable at its own relay door. Remote attach dials the target’s own public or custom-domain address. A machine on a LAN-only or loopback-only relay is not remotely attachable — this is the most common reason an attach fails on a machine you can otherwise see.
3. You authenticate at that door. The target’s relay door authenticates you itself, and asks for that machine’s connection PIN when one is armed. Your join key is a machine-joining credential, not a remote-terminal one, and it is not accepted at another machine’s door.

Attaching to your own machine is the easy case: it goes through the local relay and does not require the remote-door path.

After you attach

The session lives on the target machine, so losing your connection detaches you rather than ending the work. Reattaching returns you to the same session — see Remote terminal sessions.

Common questions

Can I open a terminal on a machine without SSH?

Yes, if the target is a joined Cmdop machine with a running agent and a reachable relay door. The path is not SSH: the target agent already dialed out, so Cmdop does not need an inbound SSH port on the target.

Why does attach fail when the machine is online?

Online means the machine’s agent is connected to its relay. Interactive attach also needs the target reachable at its own relay door and may require that machine’s connection PIN. A LAN-only or loopback-only relay can still make the machine visible while preventing remote terminal attach.

What should I use for AI-agent work instead of a terminal?

Use Cmdop’s fleet tools. cmdop fleet <machine> and the MCP fleet server ask a machine’s own agent to do bounded work without turning the workflow into an interactive shell. See Fleet MCP tools.

Related

• One-shot execution — for a single command instead.
• Authentication and PINs