Remote hosts

Devices is the model: a machine is a machine you can ssh to, and everything files under it. This page is the operating manual for the pane that does the work — Settings ▸ Remote Hosts, one row per machine, each opening onto that machine’s own page.

The shape is worth knowing before the details. A machine is two things at once: a route (how you reach it) and an identity (what’s installed on it). You can’t install anything on a box you can’t reach, so the pane reads in that order, and so does everything below.

Adding a host

Termio reads ~/.ssh/config and never rewrites it behind your back. Anything you can already ssh to is a machine Termio can reach — there is nothing to import.

• File ▸ Connect to… lists the aliases in your config Termio hasn’t worked on yet. Picking one opens a terminal there.
• Add Host… — at the end of File ▸ New SSH Connection, and on the Remote Hosts pane — appends a Host block for a box that isn’t in your config yet. Lead with the address; the name is what you’ll type after ssh. If your other hosts already share a user and a key, that pair is offered rather than retyped.

A host you add this way is an ordinary ~/.ssh/config entry afterwards. The machine’s page carries a Host block ▸ Edit row that opens the entry it was defined in, so the config stays the one place the answer lives.

Testing the route

The Reached by section names the destination and says how ssh will sign in — either the key your config pins, or “the keys ssh offers on its own”. Beside it is a Test button. It reports one of four outcomes, the last of which carries ssh’s own reason rather than a fixed label:

Test with the machine’s own alias, the same way the rest of the app reaches it. If ssh mybox fails in your terminal, this will fail too — Termio carries no credentials of its own.

Why a password isn’t enough

A host that takes a password will let you open a plain terminal and nothing else. The connections that carry sessions, the file tree, search, and the git panes all run non-interactively (BatchMode=yes), which means they can never answer a prompt. A password works exactly where a human is sitting there to type it, and fails everywhere else.

So the pane says that plainly and offers the fix in place: Set Up Key… runs ssh-copy-id in a terminal with the key Termio would use. The host asks for your password once, there, and from then on every path can reach it. If ~/.ssh has no key ssh would offer on its own, the row says so and points at ssh-keygen first.

Setting it up

Getting a box ready is a real dependency chain — put the server there, find out which agent CLIs it has, write Termio’s hooks and skill into them. Showing that as four independent states would turn picking a machine into infrastructure triage, so the pane promises one outcome and keeps the rungs underneath it:

Pressing Set Up walks the ladder: copy termiod into ~/.local/bin over SSH, probe for your agent CLIs, then bring the hooks and the skill into line with what the switches on Settings ▸ Agents ask for — installing each half, or removing it, per switch. With both off it deliberately installs neither, and the line then promises only that agents there can run. No root, no package manager, nothing added to your shell profile.

When a rung fails, the line names that rung rather than “setup failed” — and only the first one. A machine with no termiod also has no hooks, and naming both invites you to fix the consequence instead of the cause.

Agents on that box

A remote machine’s page carries an Agents link — “what does this box have” — which is the same question as Settings ▸ Agents asked from the other axis. Opening it gives you:

• Command paths. One row per agent, each with the machine’s own answer underneath: Installed, Not installed, or Can’t check. Leave a path empty to launch the agent the way that machine’s login shell would; fill it in (/opt/homebrew/bin/codex) when the binary lives somewhere the profile doesn’t add. Which agents appear at all is still Settings ▸ Agents.

• Installed by Termio. What Termio wrote into each agent’s config on that machine — Hooks (so agents report their status) and the Skill. One Reinstall Hooks and Skill button repairs both; reach for it after hand-editing one, or when a status dot stops moving.

  The skill a box gets is not the one this Mac gets. Agents here learn termio sessions, scoped to their own project; agents on a machine learn termiod list, create, send and kill, scoped to that whole machine — because that is the command that exists there.

Can’t check is a third answer on purpose, and it’s never a defect in the agent: it means Termio couldn’t reach the machine to ask. Reporting that as “not installed” would send you to reinstall a CLI that’s already there; reporting it as “installed” would promise a launch that can’t happen.

Keeping a host current

The same Set Up button is the update. It works from any state — nothing installed, an older build, a build the running daemon hasn’t picked up yet — and it puts the old binary back if the new one doesn’t answer. The machine’s page shows the version it’s actually running.

An update that would interrupt work in progress doesn’t take it. The line reads Update ready, names the session holding it up, and offers Update Anyway beside it. Left alone, the new build takes over the next time the daemon stops on its own. Your idle terminals never hold an update back; a command still running or an agent mid-task does.

From the command line the same reconcile is one verb:

termiod deploy --host mybox

It ends in the same state whatever state it started in, so running it against a box that looks wrong is safe. See The Termio server.

When a host stops answering

Work from the outside in — ssh first, then the daemon, then Termio:

ssh mybox true                 # does SSH itself work?
termiod list --host mybox      # is the server answering there?
termiod deploy --host mybox    # reinstall and verify it

A dropped connection detaches you; it doesn’t kill anything. The sessions are on that box, in its daemon, and reattaching restores the screen — see What survives. If they really did go away after a reboot, the box is missing a service: termiod service install.

The device switcher reports an unreachable machine in ssh’s own words rather than going quiet, so the failure you read is the failure ssh had. More symptoms and their checks are in Troubleshooting.