Architecture

Overview

Companion Hub is built as a modern, modular self-hosting platform with several interconnected components.

Core Components

Hub (Local Server)

The Hub is the main application running on your server:

Backend: NestJS 11 with TypeScript
Database: PostgreSQL 14 with Drizzle ORM
Frontend: React 19 dashboard
Desktop app: Tauri 2 native wrapper for macOS, Windows, and Linux
Message Queue: RabbitMQ 4 for async task processing
Reverse Proxy: Traefik v3 for routing and SSL

CI Account (hub.ci.computer)

The cloud companion at hub.ci.computer that provides:

Remote Hub management
Device pairing
Managed Cloudflare Gateway provisioning
Remote App Store access

Cloudflare Gateway

A managed Cloudflare Tunnel that securely exposes your apps without port forwarding. Provisioned and managed through your CI Account.

Docker Layer

All apps run as Docker Compose projects. Each app is isolated in its own compose stack but shares a common Docker network for inter-app communication.

Docker Services

The Hub runs several containers defined in the production compose file:

Service	Image	Purpose
`ci-os-hub`	Hub backend + frontend	Main application (API on port 5002)
`ci-hub-db`	PostgreSQL 14	Database (port 6543)
`ci-os-hub-queue`	RabbitMQ 4	Message broker
`ci-hub-traefik`	Traefik v3	Reverse proxy, SSL, routing
`hub-tailscale`	Tailscale	Private VPN sidecar (enabled by default; optional to disable)
`cloudflared`	Cloudflare tunnel agent	Managed gateway (optional)

Technologies

Docker — Containerisation
Traefik — Reverse proxy and load balancer
TypeScript — End-to-end type safety
NestJS — Backend framework
React — Dashboard frontend
Tauri 2 — Cross-platform desktop app
Drizzle ORM — Type-safe database access
PostgreSQL — Database
RabbitMQ — Message broker
Tailscale — Optional private networking