Sign In Without a Browser: EntVista Hub's Headless CLI

Introduction

Signing in is easy when there is a browser on the machine: a window pops up, you log in, and you are done. However, a lot of real work happens on machines with no browser at all, or any kind of GUI implemented. For example, a GPU training server, a continuous-integration runner, a Linux box you only ever reach over SSH. In such mediums, there is nowhere for a login window to appear.

EntVista Hub's headless command-line mode (generally available in version 2026.2.1) solves exactly that. In this article, I will talk about the command-line sign-in flow, including the device code and QR code that you can scan from your phone, and then explain how one login covers every tool on the host.

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The Problem with Headless Sign-In

As mentioned in the introduction, the usual desktop login is a "browser redirect". That is, the app opens a browser, you authenticate, and the browser hands the result back to the app. This method depends on three things: a browser, a desktop session, and a way for the browser to talk back to the app on the same machine.

This method works often times for most users. However, when scaling up to headless hosts, none of those are present or guaranteed. So, instead of trying to open a browser that is not there, EntVista Hub uses the device authorization flow: the headless machine shows you a code through its CLI, and you can approve that code from a browser on any device you like. This can your laptop, your phone, or another workstation.

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Signing in from the Command Line

First thing to do is to bring up the EntVista Hub in command-line mode, which will ask it to sign you in:

EntVistaHub --mode cli auth login

This will print a sign-in URL and a short one-time code, on top of a QR code you can scan with your phone:

  Open this URL in a browser to sign in:

      https://accounts.entvistastudio.com/realms/entvistastudio/device

  Then enter this code: YRNP-LMRW

  ( One-shot link: https://accounts.entvistastudio.com/realms/entvistastudio/device?user_code=YRNP-LMRW )

  Or scan the QR code below with your phone:


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  Waiting for authorization...

You then have three methods as to approve. All of these methods will reach the same place:

1. Open the URL on any device and type the code provided.
2. Click (or paste) the one-shot link, which fills the code in for you.
3. Scan the QR code with your phone's camera.

Sign in, approve the request, and the headless machine completes automatically:

  ✓ Signed in as you@example.com

From that moment, the tokens will live on the headless host. Nothing else is needed!

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Companion Commands

Furthermore, three subcommands cover the whole lifecycle, and each one exits with a status code your scripts can read:

EntVistaHub --mode cli auth login    # device-code sign-in, saves your session, exits
EntVistaHub --mode cli auth logout   # signs out and clears the local session, exits
EntVistaHub --mode cli auth status   # prints the active environment + who is signed in, exits

auth status is the one you will reach for most in automation. It tells you whether the host already has a valid session before a job tries to use it.

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One Login, with Every Tool on the Host

This is the part that makes it all worth it. EntVista Hub is designed to be the single sign-in authority for our entire family of EntertainmentVista Studio tools (more to come soon!). As a result, once you have signed in on a host, every tool you have installed shares the same session.

For example, a Metrixel batch job that simply just works:

# 1. Sign in once (device-code flow above)
EntVistaHub --mode cli auth login

# 2. Run Metrixel headless — it reuses the same session, no second login
metrixel --mode cli --gen_mode batch --input /data/in --output /data/out

With a single sign-in procedure, both products are authenticated. When it's time to sign out, both products will lose access. There are no separate token caches for the command line, and there is no risk of the two getting out of step.

If you do not pass an auth subcommand, --mode cli keeps running quietly in the background as the sign-in service that other tools talk to. This is what the Metrixel example above relies on.

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Built for Cloud and CI

Because both the sign-in and the tools can run without a display, the whole flow is streamlined into automated environments. Such examples are:

• Amazon SageMaker training jobs that need authenticated access to the pipeline,
• CI/CD runners that build or validate datasets on every commit,
• SSH-only Linux hosts and remote GPU servers.

Pair these with the silent, unattended install (which is covered in our Linux post) and a machine can go from bare to signed-in - entirely from a script.

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Production Use and Known Limitations

The headless command-line login is generally available and supported for production use. All you need to do is to pin a specific EntVista Hub version in your CI pipelines, while you settle on a flow.

However, there is still one rough edge that we are still in the middle of smoothing: On the command line, moving your seat from another device is not yet automatic. A headless run will instead tell you which device holds the seat and stop, so that you can decide on this. We're improving on this method of handoff in a follow-up.

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Who Is This For?

• AI/ML engineers launching training jobs on remote GPU servers,
• Platform and DevOps teams automating dataset builds in CI,
• Researchers working on SSH-only Linux hosts with no desktop,
• Anyone who has ever been stuck because "there is no browser on this machine".

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Conclusion

A browser-less machine should not result in a dead end for services that require a sign-in. With EntVista Hub's headless command-line mode, you authenticate with a short code and a QR, approve it from whatever device is in your hand, and every EntertainmentVista Studio tool on the host is ready to run. It is a small flow that unlocks the cloud and CI workflows our users have been asking for.

Up next:
Running the entire Metrixel pipeline from the command line — single files, full batches, and machine-ready output.