ScalebrowserDOCS

Machines & sign-in

Every install belongs to your account: how a machine is paired, why one profile may only run on one machine at a time, how a takeover works, and what happens when a machine is removed.

Every install signs in once and becomes a machine on your account. That is where two limits are counted, and where one safety rule lives that is not a limit at all.

Pairing

The desktop app does it: press Sign in, a browser window opens, you sign in, and it closes by itself.

A daemon you run without the desktop app has no window, so it carries a pairing token instead:

  1. Generate a token

    Open Settings, API tokens and press Generate token. The value is shown once.

  2. Hand it to the daemon

    As SCALEBROWSER_API_TOKEN, next to the other two secrets. See Install & run.

  3. Forget about it

    The token is used once, at enrolment. From then on the daemon holds its own credential, encrypted in the data directory.

Without it, every profile start is refused with 4011.

The account comes from the session, never from the pairing code. If a code and a session name different accounts, the pairing is refused and the code is burned. Otherwise a code somebody looked over your shoulder to read would be enough to attach their machine to your account.

One profile, one machine

Independent of any plan limit: a profile runs on one machine at a time.

Starting it on a second machine of the same account is refused with 4012, and the message names the machine holding it.

This is not a licence restriction. One identity signed in from two places at once is what a relying party reads as a cloned account, which is the exact outcome the whole product exists to avoid. It applies whether or not you use sync.

Taking it over

If the other machine is at home and you are not, take the profile over. The takeover revokes the holder's right rather than deleting its row: the holder learns about it from the answer to its own heartbeat, closes the browser and releases the profile.

How a copied machine is caught

Copying a whole data directory copies the key and the token together, so two machines would otherwise run under one identity with nothing noticing. Three things catch it, and none of them alone is enough:

The proof rotates. Every renewal swaps the credential rather than extending it. A second presentation of an old one is a reuse.

A counter climbs. It rides in the payload and in the signature. Two instances under one identity contradict each other in it, even if they take turns.

The row is read on every call, not only when a credential is issued. That is why a revocation bites within minutes rather than at the next renewal.

Removing a machine

Settings, Devices lists them and removes one.

Removal bites immediately. A removed machine does not get the outage grace window, because that window is for a control plane nobody can reach, and handing it to a machine that was explicitly refused would hide the removal for hours behind a screen still saying the account is connected.

Signing in again on that machine re-enrols it. A fresh pairing token reopens the door; an unchanged one does not.

What a machine costs

One machine slot. See Plans & limits for how many each plan carries, and the add-on for buying more.

Browsers are counted separately, across all your machines together.

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