Run persistent Claude Code sessions on a headless server

I’ve really enjoyed working with Anthropic’s models ever since Opus 4.5. They read between the lines and get my intent, and Opus, now Fable too, is genuinely good at my weapon of choice, Rust. Fable 5 came and went fast in June: available for only a few days before the US government applied export restrictions on it. Now it’s back for a week as part of my Claude Max subscription, and I have a long list of things I’d like to throw at it.

The catch: it’s vacation season here in Sweden, I have a trip planned, and I don’t want to bring the laptop. I’ve used Claude Code’s /remote-control feature for a while. It’s a great way to keep an eye on a session while you’re out and about, but you still need a computer running somewhere to host it. We’ve all seen the 3D-printed brackets that keep a MacBook lid from closing.

I have a small HP server at home running some homelab stuff, and I’ll occasionally SSH in to do development. The problem is that a plain SSH session dies the moment the connection drops. For everyday work I reach for zellij. I find the UX nicer, the keybindings more discoverable and the defaults friendlier. But I couldn’t get a zellij session to stay alive across a disconnect (could be me, could be how its server attaches to the session), so for this I switched to tmux, which daemonizes itself and just kept running. After some trial and error I landed on a setup that works great for my use case, so here’s a writeup for the next time I need it.

The always-on dev machine

First you need a machine that’s always on. That could be a cloud-hosted VPS, an old box in the basement, or in my case a Proxmox VM on my home server.

I spun up the VM, installed a headless Arch Linux, added my SSH key, and set it up with a nice Zsh shell and a starship prompt. Then I installed the terminal tools I use day to day: Rust, Node, Python, git, gh-cli, helix, ripgrep, zellij, Claude Code, and of course tmux.

Easy things to forget

• Generate a new SSH key and add it to GitHub, Codeberg, GitLab, or wherever you keep your projects.
• Set the global git config for user.name and user.email.
• Authenticate the gh-cli with gh auth login if you want Claude to open PRs for you.

Long live the session

Because tmux daemonizes its own server, a detached session already survives logging out of SSH, or even outright killing the connection from your client. That was the whole reason I switched to it.

There’s still one systemd wrinkle worth knowing about: some distros are configured to reap a user’s leftover processes on logout (the KillUserProcesses setting in logind.conf; Arch leaves it off by default). To keep the setup robust no matter how a box is configured, I enable lingering for my user:

sudo loginctl enable-linger $USER

Lingering lets a user’s services and processes keep running without an active login session, exactly the state I’m after here. On my Arch box tmux survives without it, but it’s cheap insurance for a machine I want to leave running and rely on while I’m away.

SSH straight into tmux

You could SSH into the machine and run tmux attach every time, but wouldn’t it be nicer to SSH straight into your tmux session? Here’s how I have my ~/.ssh/config set up:

Host dev-claude
    RequestTTY yes
    RemoteCommand zsh -l -c "tmux new -A -s claude"

Host dev dev-claude
    HostName 10.10.1.123
    User lhelge
    IdentityFile ~/.ssh/id_ed25519

Now ssh dev-claude drops me directly into the claude session, creating it if it doesn’t exist yet (tmux new -A), while plain ssh dev still gives me a normal shell.

That’s it. Laptop stays home, the session stays alive, and Fable keeps chewing through my backlog while I’m away.