Install

Node.js 20 or newer.

npm i -g localberth

or

pnpm add -g localberth

Then claim a port and start your app with it:

localberth claim fizzbuzz --port 5193
PORT=$(localberth get fizzbuzz)

On Windows PowerShell:

$env:PORT = localberth get fizzbuzz

Open the dashboard:

localberth serve

Then visit http://127.0.0.1:54321.

From a phone on the LAN, claim with --lan (binds 0.0.0.0 and syncs the firewall):

localberth claim fizzbuzz --port 5193 --lan

When you are done with a name:

localberth release fizzbuzz