Requirements

MultiDocker targets macOS. The DNS resolver and TLS trust it configures are macOS-specific; Linux is possible but the DNS setup must be done by hand, and Windows is out of scope.

System

• macOS (Apple Silicon or Intel).
• A container runtime — OrbStack (recommended) or Docker Desktop.
• Homebrew to install the CLI tools below.

Container runtime: OrbStack vs. Docker Desktop

OrbStack (recommended)

OrbStack is the recommended runtime. Every container is automatically reachable from the host at <service>.<project>.orb.local, which makes database access trivial — no manual port mapping needed.

Docker Desktop

Docker Desktop works too, but host DNS into containers is not available. To reach a database from the host you have to map a port temporarily. Everything else behaves the same.

CLI tools

MultiDocker relies on a handful of command-line tools:

Tool	Why it’s needed
mkcert	Generates and trusts the local wildcard TLS certificate.
nss	Lets mkcert install its CA into Firefox / NSS trust stores.
yq (mikefarah v4)	Parses and rewrites compose YAML when rendering overrides.
jq	Reads and writes the JSON registry and command output.
openssl	Certificate helper used during TLS setup.

Install them in one go with Homebrew:

brew install

brew install mkcert nss yq jq

yq must be the mikefarah variant

There are two different tools called yq. MultiDocker needs mikefarah’s yq v4 (the Go implementation, installed by brew install yq), not the Python yq wrapper around jq. Check with yq --version.

Optional tools

• cloudflared — only needed for public demo tunnels (mdocker share). Install with brew install cloudflared.
• tmux — required for AI terminal sessions.
• TablePlus — a nice target for mdocker db open, but any client works.

Tip

You do not have to remember this list. After installation, mdocker doctor checks every required tool and tells you what is missing — see Running mdocker doctor.

Next

Continue to Installation.