Quickstart

By the end of this tutorial you will have the rb CLI installed, a signed-in session, a GPU blade of your own, and a command running on it. It takes about ten minutes, and the €10 of credit that comes with a new account is enough to finish it.

You need Python 3.11 or newer and an SSH client. On Windows, use WSL.

1. Install the CLI

The CLI is published to PyPI as rb-cli and is best installed with pipx, which puts it in its own environment and on your PATH.

# macOS
brew install pipx
pipx install rb-cli

# Linux, or inside WSL on Windows
pip install pipx
pipx install rb-cli

Check it works, and turn on tab completion for your shell:

rb --version
rb --install-completion

2. Point the CLI at the API

export RB_API_URL=https://api.razorbridge.eu/v1

Caution

Do this before your first command. The version currently on PyPI ships a default API address that no longer resolves, so without RB_API_URL every command fails with a connection or 404 error. Put the export line in your shell profile so you do not have to think about it again. rb doctor prints the address in use.

Confirm the CLI can reach the API:

rb doctor

It reports the CLI version, the API address, where your credentials will be stored, whether you are signed in, and whether the API answered.

3. Sign in

rb auth login

The CLI prints a URL and an eight-character code, and tries to open your browser. Sign in to razorBridge, type the code into the Authorize razorBridge CLI page, and submit it. The terminal picks up the approval within a few seconds.

The code is valid for 15 minutes and the CLI waits up to 5 minutes for you. If either runs out, just run rb auth login again.

Your access token is written to ~/.config/rb/token with 0600 permissions. It lasts an hour and the CLI refreshes it silently for up to 30 days.

Check who you are and what you have:

rb auth status

4. Start a GPU

There are two ways to get a blade. Pick whichever applies to you.

If you are on your own: start a self-serve session

Self-serve sessions are started from the web app, not the CLI.

1. Sign in at razorbridge.eu and open the Hub.
2. Go to GPU Sessions and choose New session.
3. Pick a GPU type (the dropdown shows VRAM and the current hourly rate) and a Duration — 1, 2, 4 or 8 hours.
4. Choose Start session.

The session appears in the table and moves from Pending to Provisioning to Running, usually within a few minutes. It stops itself when the duration is up, and you are billed for the time it actually ran.

If you were given a join code: join the event

rb event join ABCD-1234

Join codes are four letters, a hyphen and four digits, and are not case-sensitive. Your blade is created shortly before the event’s start time — not at the moment you join — and the organizer’s credits pay for it. rb event info ABCD-1234 shows the start time and, once it exists, your blade.

5. Watch it come up

rb blade list
rb blade status

rb blade status with no arguments reports on your most recent running blade: GPU type, status, IP address, region, and how long is left. Wait until the status is running before trying to connect.

6. Connect and run something

rb blade ssh

This opens an interactive shell on the blade. Authentication is by password: if sshpass is installed the CLI supplies it for you, otherwise it prints the password for you to paste once.

nvidia-smi

To run one command without opening a shell — handy for kicking off training — use rb run, which streams the output back and exits with the command’s exit code:

rb run nvidia-smi
rb run "python train.py --epochs 10"

Tip

For an editor-based workflow, rb blade config prints an SSH Host block you can paste into ~/.ssh/config. The alias it generates is rb- plus the first eight characters of the blade id, so you can then use ssh rb-abc12345, VS Code Remote-SSH or JetBrains Gateway. Because blade access is password-based, your SSH client will prompt for the password each time.

7. Move files in and out

# upload into your home directory on the blade
rb blade scp ./train.py

# download one result file
rb blade scp blade:~/results/metrics.json ./

Anything with a : that does not start with / is treated as a remote path, so blade:~/results/metrics.json reads from the blade and a bare local path writes to it. rb blade scp copies single files. For a whole directory, add the SSH config block from step 6 and use scp -r or — better for large or interrupted transfers — rsync:

rsync -avP rb-abc12345:~/outputs/ ./outputs/

8. Check what you spent, and stop

rb credits
rb status

rb credits shows your balance and recent ledger entries; rb status is a one-screen overview of blades, upcoming events and balance.

A self-serve session keeps costing credits until it stops, so stop it as soon as you are done: Stop on the session row in the web app. Event blades are torn down for you shortly after the event ends.

Caution

A blade’s disk does not survive teardown, and there is no warning to participants before an event ends. Copy anything you want to keep off the blade while it is still running.

Where to go next

• GPU blades and sessions — provisioning, extending, what the statuses mean, and the account limits that apply.
• Inference gates — call models over an OpenAI-compatible API, billed from the same balance.
• CLI reference — every command and flag.
• Troubleshooting — if any step above did not go as described.