The big picture
Offsite is an agentic development environment built on the CLI. Your coding agents run on a real machine that you own. Your Mac, iPhone and Watch are live surfaces onto that machine.
Nothing sits between the agent and its provider. Nothing sits between you and the agent.
Why the CLI is the harness
Section titled “Why the CLI is the harness”The labs that build the frontier models also build the best harness for them,
and they ship it as a command-line tool. claude, codex and grok are where
new capabilities land first: new models, new tools, MCP servers, skills, hooks.
A third-party wrapper is always a release behind, and always a subset.
So Offsite does not wrap them. It starts the real binaries, with your config, your MCP servers, your skills, your subscription and your keys. When a CLI ships something new, you have it the same day — on your Mac and on your phone.
That is also why Offsite never touches your tokens. The CLI talks to Anthropic, OpenAI or xAI straight from your machine. Offsite resells no compute and meters nothing.
Your machine, from anywhere
Section titled “Your machine, from anywhere”An agent session is a long-running program. It should not die because you closed a laptop.
So sessions belong to the host, not to the app. They run in host-owned tmux: close the lid, lose Wi-Fi, quit the app, reboot the machine — the work carries on, and Offsite brings the conversation back through the CLI’s own resume.
Your devices reach the host over whichever path is fastest and actually reachable: direct on the local network, over Tailscale, or through an end-to-end-blind relay that you can switch off per host. The path switches live when a better one appears, and the connection pill always names the one in use.
The point is not remote access. The point is that it stops mattering which device you are holding. Same board, same sessions, same input, same moment — as if you were sitting in front of the machine.
Your agents tell you when they need you
Section titled “Your agents tell you when they need you”An agent that finished four minutes ago while you were looking elsewhere has cost you four minutes.
Offsite notifies you when a turn finishes and when an agent is waiting for your input. Both are on by default; session ended and errors are off. Every device you have paired carries its own settings, so your phone can stay quiet while your Watch taps you.
Notifications name the session, so you know which agent wants you, and tapping one opens exactly that session. They are built on the CLIs’ own hook and notification interfaces rather than on scraping the screen, which is why a CLI update does not quietly break them.
The loop closes on the device in your hand
Section titled “The loop closes on the device in your hand”Prompting from a phone is table stakes. Testing is not — and testing is where remote work usually breaks down and sends you back to the desk.
There are three ways back to you, depending on what you are building:
- A web app. The dev server your agent just started listens on the host. Offsite tunnels it to the device in your hand, so you open the app and tap through it for real.
- An iOS app in the Simulator. The host’s Simulator runs as a card on your board, mirrored live, with your taps and typing going back into it.
- An iOS app on the actual phone. Deploy to this phone builds on the host and installs the result on the iPhone you are holding. No TestFlight detour, no Mac in sight.
Then you say what is wrong, from the same device. Prompt, work, test, prompt.
Hosts, sessions and clients names the three pieces the rest of these docs use. After that, Prerequisites and Install & set up get you running.