Getting started

Everything you need to run the demo locally or deploy it to production.

Prerequisites

  • Node.js >= 20
  • Docker (for Postgres and Redis, or bring your own)

Install

npm install

Configure

Copy the example env file:

cp .env.example .env

The defaults point at localhost which works if Postgres and Redis are running in Docker on standard ports.

Create the database

psql $DATABASE_URL -f schema.sql

The last_activity column is auto-migrated on startup if missing.

Dev mode

npm run dev

If DATABASE_URL is not set, the app falls back to an in-memory store. You can develop without Postgres or Redis - all realtime features still work locally, just not across multiple server instances.

Production build

npm run build
npm start

Deploy with Docker Compose

The included docker-compose.yml sets up everything: app, Postgres, Redis, and a certbot container for automatic Let’s Encrypt TLS. HTTPS out of the box, no reverse proxy.

The app runs as 2 independent replicas using network_mode: host and SO_REUSEPORT. The Linux kernel distributes incoming connections across both processes. Redis handles cross-process pub/sub.

Steps

  1. Point a domain at your server (A record)

  2. Create a .env file:

DOMAIN=your-domain.com
POSTGRES_PASSWORD=pick-a-strong-password
  1. Get the initial certificate:
docker compose run --rm certbot certonly --standalone -d your-domain.com
  1. Start everything:
docker compose up -d

The app listens on port 443 directly (host networking). Certbot renews automatically every 12 hours. Postgres and Redis data are persisted in Docker volumes.

Scaling replicas

docker compose up -d --scale app=4

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