Document · Licensing · 6 min read

Activate a license on a device

A Kaptain license belongs to a CHYNJ account (your email). "Activating" a device means binding that machine to the license so Kaptain runs in Pro. You can do it two ways — sign in with your CHYNJ account, or paste the license key — and you can see and manage every connected device from your account.

How licensing works

Three facts make the rest of this page simple:

A license is attached to your CHYNJ account email. However your license was issued, it is tied to the email on your account.
A device is "connected" when its fingerprint is registered against the license. Kaptain does this for you when you activate — you do not manage fingerprints by hand.
Your account is the source of truth. Your license key and the list of connected devices always live at chynj.ca/account, even if an email never arrives.

Step 1 — Find your license

When a license is issued to you, CHYNJ emails the key and these same steps. If that email hasn't arrived, don't wait on it — get the key directly:

Go to chynj.ca/account and sign in with your CHYNJ account.
Under License, your Key is shown as KAPTAIN-XXXXXXXX-XXXX-XXXX with a Copy button.

If you don't have an account yet, create one at chynj.ca/account using the same email the license was issued to, then the license appears automatically.

Step 2 — Install Kaptain on the device

Install the runtime on the machine you want to use, then start it. Full steps are in the Setup Guide. In short:

curl -sL https://chynj.ca/install.sh | sh   # Linux / macOS
kaptain start

kaptain start runs the server in the background, prints the URL and log file, and opens the browser at http://localhost:8810. The bare command kaptain with no arguments prints the command list and exits; it does not start anything. The one exception is Windows, where double-clicking kaptain.exe in Explorer starts the server, because there is no terminal for the command list to be read in. Per-platform detail: macOS, Windows, Linux, terminal install.

On a machine that has not been set up, Kaptain opens the setup wizard at that address. Activation happens during the wizard's plan step, and can be redone later from Settings.

Step 3, Option A — Activate by signing in (recommended)

This is the "connect my device to my CHYNJ account" path. You don't copy any key.

On the wizard's Account step, stay on the Sign in tab and enter the email and password for the account the license is on. If your account uses two-factor, the wizard asks for the 6-digit code next. Google and GitHub buttons appear here too when your CHYNJ account service offers them.
Kaptain checks your account with license.chynj.ca, finds the license attached to your email, and applies it.
This machine is registered to the license automatically and shows up under Devices in your account.

Use this path when the person at the device knows the account login. It keeps every device tied to one account with nothing to paste.

Step 3, Option B — Activate by license key

Use this when you only have the key (for example, you forwarded the key to a teammate's machine).

Continue to the wizard's Plan step, which shows your trial or license state.
Click Have a license key? to reveal the key field. On a machine whose trial has expired the field is already visible.
Paste your key (KAPTAIN-XXXXXXXX-XXXX-XXXX) and continue. The button reads Activate & Continue once a key is expected.

Kaptain validates the key with license.chynj.ca and registers this device against it. The result is identical to Option A — the device is now connected to the license.

Restoring access after a trial (incl. a remote machine)

Common situation: a machine ran the free trial, the trial ended, and you've since issued or bought a license — but that machine still shows "Trial expired." A trial is tied to the machine, not to your CHYNJ account, so the machine doesn't yet know about the new license. You restore it the same way you activate — and you do not need to reinstall.

The license and sign-in screens stay reachable even when a trial has expired, so you're never locked out of recovery. On that machine:

Best — sign in with your CHYNJ account. This links the machine to your account. From then on it re-checks your account every few hours and applies whatever license is on it — so this and any future renewal activate automatically, with nothing else to do.
Or paste the license key on the "Trial expired" screen and activate.

If the machine is somewhere else (you're remote)

You need to reach that machine's Kaptain screen once:

If you enabled Tailscale during setup, open http://<that-machine's-tailscale-address>:8810 from anywhere and sign in / enter the key.
Otherwise use SSH or remote desktop to that machine and open http://localhost:8810 there.

Why account sign-in is the durable fix: once a machine is signed into your CHYNJ account, licensing becomes automatic and remote. Issue, renew, or move a license on your account and every signed-in machine reflects it within a few hours (or immediately on restart) — you won't have to touch the machine again.

Add a device remotely from the command line (headless)

For a server or any machine you only reach over SSH — no desktop, no browser on the box — register it with a device-authorization grant. You approve a short code in your account from any other device. You do not need to hand-edit kaptain.json.

Start registration on the box. It prints a URL and a short code, then waits:
```
kaptain device register
```
Optional flags: --nickname "build-server" to label it, --no-browser to skip the browser launch attempt, --json for machine-readable output. There is no token flag — nothing is pasted into this command.
Approve it from any device with a browser: open the printed URL, sign in to your CHYNJ account, and confirm the code shown on the server.
Save the access code. Once approved, the box finishes automatically and prints a local access code (chynj_…) once. That is what a browser uses to connect to this Kaptain. Store it before closing the session.
Restart so the running server picks up the new certificate:
```
kaptain stop
kaptain start
```
Connect a browser (optional). With Tailscale enabled, open http://<machine-tailscale-address>:8810 and paste the access code when the pairing screen asks.

The licence follows the account that approved the device, so there is no separate activation step on the machine. Check it with kaptain license status, and force a re-check with kaptain license refresh. kaptain account status shows which account the box is bound to; kaptain account open opens the portal.

There is no kaptain account signin or kaptain license set. account accepts only status and open; license accepts only status and refresh. Earlier versions of this page documented a token flag and both of those commands; none of them exist in the Go build, and a password is never typed into the CLI. Approval happens in the browser, against your account.

Devices & limits

Each license allows a fixed number of connected devices:

Pro — up to 5 devices.

Activating a 6th device on a Pro license is refused until you free a slot. Device binding uses a hashed machine fingerprint — Kaptain never sends the raw fingerprint, only its SHA-256.

Manage / disconnect devices

From chynj.ca/account, the Devices list shows every machine using your license, with its nickname and last-seen date.

To free a slot or remove a machine you no longer use, click Sign out next to that device. Kaptain on that machine stops running Pro until it is re-activated; your account and other devices are unaffected.
Re-activating a previously removed device is fine — just run Option A or B again on it.

Validation & offline use

After activation, Kaptain re-checks the license with license.chynj.ca on startup and roughly every 4 hours. If the machine is temporarily offline, Kaptain falls back to a signed local cache so work continues; it re-validates as soon as it's back online. You do not need to re-enter anything.

Troubleshooting

No license email arrived. You don't need it — sign in at chynj.ca/account and copy the key from the License card, or just use Option A (sign in inside Kaptain). Also check spam for mail from [email protected].
"No license found for this account." The license must be on the same email you signed in with. Confirm the email on chynj.ca/account matches where the license was issued.
"Device limit reached." Open chynj.ca/account → Devices and sign out a machine you no longer use, then activate again.
"Invalid license key." Re-copy the key from your account (use the Copy button) to avoid stray spaces, and make sure it has the form KAPTAIN-XXXXXXXX-XXXX-XXXX.
Need to move a license to a new machine. Activate on the new machine, then sign the old one out from chynj.ca/account → Devices.

Still stuck? Email [email protected].