Architecture

Mezzanine is a single SQLite-backed Express + Next.js panel that opens SSH connections out to your servers. Nothing about it is special-cased to a particular cloud — every provider integration is a thin API wrapper on top of the same primitives.

System architecture

Three containers on a single Docker network:

Service	What it does	Image
mezzanine-nginx	TLS terminator + routing	nginx:1.27-alpine
mezzanine-frontend	Next.js SSR + static assets	Local build (Dockerfile.frontend)
mezzanine-backend	Express + Socket.IO + SSH/Docker services	Local build (Dockerfile.backend)

State lives in one named volume (mezzanine_data) mounted at /data inside the backend container. That’s the only thing you need to back up — everything else is reproducible from git + a fresh docker compose build.

Out to your fleet

For each adopted server, the backend opens one SSH connection on demand (pooled, idle-timed) and runs commands as the configured user. For each provider, it holds OAuth2 / API-token credentials in the integrations table and makes signed HTTPS calls. The control plane never sits in the data path — it configures and observes, but in-pool traffic flows browser → LB → members directly.

Code layout

mezzanine/
├── backend/src/
│   ├── routes/          # /api/* — thin Express handlers
│   ├── services/        # business logic, SSH/Docker/provider clients
│   ├── websockets/      # Socket.IO namespaces (terminal, metrics, logs)
│   ├── middleware/      # auth, role-gate, response cache
│   └── db/index.ts      # SQLite schema + migrations
├── frontend/
│   ├── app/             # Next.js App Router pages
│   ├── components/      # shared React components
│   ├── api/client.ts    # axios client + per-resource API namespaces
│   └── lib/             # helpers (dialogs, workflow templates, transformers)
├── samples/             # reference apps + this docs site + landing page
└── deploy/              # Production artifacts (docker-compose, nginx.conf, INSTALL.md)

Why SQLite?

Single-file storage trades horizontal scalability for operational simplicity:

• One file to back up. cp mezzanine.db /backup/ is your DR plan.
• No DB server to provision, monitor, or upgrade
• better-sqlite3 is synchronous → no async ceremony around every query
• Easily handles 100K runs + 10K servers on a $5 VPS

If you outgrow it (>100 concurrent users, multi-region setup), swap for Postgres — the schema is portable.