Requirements

You need three things: a machine, a container engine, and — only for a public instance — a domain name.

1. A machine

The whole stack runs as five small containers (backend, frontend, PostgreSQL, Redis, Caddy). Everything is bundled, so the only thing you install on the host is a container engine.

Resource	Local test	Standalone blog	Public federated instance
CPU	1 vCPU	1 vCPU	2 vCPU
RAM	1 GB	1 GB	2 GB
Disk	2 GB free	a few GB (grows with uploads)	5 GB+ (grows with uploads)
Architecture	amd64 or arm64	amd64 or arm64	amd64 or arm64
Domain	not needed	optional	required
Open ports	none (localhost)	80 + 443	80 + 443, publicly reachable

Notes:

• Architecture — all base images are multi-arch, so a cheap ARM VPS works as well as x86.
• 1 GB RAM is enough for standalone or low-traffic use. Federation adds inbound delivery and background jobs, so treat 2 GB as the real floor for a public federated instance.
• Redis is optional. It ships in the default stack for durable queues and shared rate limits, but the app runs entirely in-process without it — drop it to save memory on the smallest boxes.
• No managed database, TLS certificate, or secret to provision. Postgres, the Let’s Encrypt certificate, the session secret, and the database password are bundled or generated on first boot.

2. A container engine

Either works — the stack is engine-agnostic and the installer auto-detects docker compose, docker-compose, podman compose, or podman-compose.

• Docker with the Compose plugin. Install via docs.docker.com/engine/install.
• Podman 4+ with podman compose or podman-compose. See Running on Podman for the one difference (binding ports below 1024 when rootless).

Verify Docker is ready:

docker --version
docker compose version

3. A domain name

Only for a public instance. You need a domain (for example blog.example.com) and the ability to add a DNS record for it. You do not need one to try Omicron locally.

What you do not need

• A managed Postgres.
• Certbot, or any TLS certificate handling.
• A reverse proxy in front (Caddy is included, and it is the entrypoint).
• An SMTP server of your own — the wizard offers a zero-setup console mode, and any provider’s SMTP or API works.
• Any file editing at all, before or after installation.