Run Kaptain on Linux

Allow it to run

1. Go to your downloads: cd ~/Downloads
2. Make it executable: chmod +x kaptain (the download saves as kaptain on both x86-64 and ARM).
3. Move it onto your PATH: sudo mv kaptain /usr/local/bin/kaptain
4. Start it: kaptain start

No sudo is needed to run Kaptain — only to copy it into /usr/local/bin. To avoid sudo entirely, move it to ~/.local/bin instead, as long as that is on your PATH.

Keeping it running

kaptain start runs it in the background and prints the URL, the bind address, and the log file. kaptain status shows whether it is up, and kaptain stop shuts it down.

The download is saved as plain kaptain for both Linux builds — uname -m only decides which build you pick on the download page.

What happens on first run

1. Kaptain opens at localhost:8810 in your browser.
2. The setup wizard walks seven steps: account, plan, models, install, project, network, done. First: create your CHYNJ account or sign in — a verification email follows (the account works right away, but the free trial waits for the verified address).
3. On the plan step, start the free 3-day trial (no card — the clock starts only when you press it) or paste a licence key.
4. Pick a model runtime. Kaptain detects Ollama, llama.cpp, and the Claude and Codex CLIs; for Ollama and llama.cpp it shows the exact install command for your machine, while the CLIs simply show whether they are present.
5. Choose your project folder (the boundary Kaptain works inside), then pick network access: Local only (the default and most secure) or Tailscale for your other devices. The done screen shows your access code once — save it.

The trial is tied to this device, so reinstalling does not start a new one. Subscribing later keeps everything you set up here.

Stuck? [email protected].

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