machine0-nixos

This repository contains the profiles that are used to build the machine0 NixOS system images. This is a great place to start if you want to customize your NixOS VM.

Usage

# install the machine0 CLI
curl -LsSf https://machine0.io/install.sh | sh

# create a NixOS VM
machine0 new nixos --image nixos-25-11-loaded --size medium

# clone the repo, customize and rebuild
git clone https://github.com/fdmtl/machine0-nixos.git && cd machine0-nixos
claude -p "make any change to the loaded profile you'd like"
machine0 provision nixos ./flake.nix#loaded

# or, rebuild from within the VM
machine0 ssh nixos
git clone https://github.com/fdmtl/machine0-nixos.git && cd machine0-nixos
./rebuild.sh

Note: We strongly recommend --size medium or larger. Nix builds are CPU and memory intensive — small instances work but take forever.

Profiles

The (profile → image) mapping is canonical in manifest.json and consumed by the build/test scripts.

Optional services

Toggleable via options on base and everything built on it (loaded/openclaw/hermes):

machine0-profile-inject (in modules/machine0.nix, always present) is what actually lands a profile's credentials — codex/github/claude-code OAuth, the machine0 MCP API key — onto the VM from the --profile flag; without it those credentials never materialize, regardless of which services are enabled.

Use as a flake input (private profile)

You don't have to fork this repo to customize it. A separate (possibly private) flake can layer its own module on top of any profile — the exported lib.mkSystem / lib.mkImage builders come pre-wired with this repo's inputs (nixpkgs, home-manager, agent flakes), so your flake needs only one input:

{
  description = "private machine0 profile";
  inputs.machine0.url = "github:fdmtl/machine0-nixos";

  outputs = { self, machine0, ... }:
    let
      system = "x86_64-linux";
      modules = [
        machine0.nixosModules.loaded   # or base / openclaw / hermes
        ./profile.nix                  # private customizations
      ];
    in {
      nixosConfigurations.private = machine0.lib.mkSystem modules;
      packages.${system}.private = machine0.lib.mkImage modules;
    };
}

A minimal profile.nix showing the common override points:

{ pkgs, lib, ... }:
{
  # Extra packages, services, secrets wiring, etc.
  environment.systemPackages = [ pkgs.cowsay ];

  # MOTD override: the profiles set this at different priorities (loaded:
  # normal, openclaw/hermes: mkForce). mkOverride 10 beats all of them.
  machine0.motd.text = lib.mkOverride 10 "welcome to my private box";

  # Auto-upgrade defaults to pulling this public repo nightly, which would
  # revert a private profile. Pointing it at a private repo also needs
  # GitHub credentials on the VM (keep any token out of the Nix store).
  # Simplest: disable it and rely on `machine0 provision` instead. To keep
  # it and point at your own repo, set system.autoUpgrade.flake with
  # mkForce (openclaw/hermes pin it at normal priority).
  system.autoUpgrade.enable = lib.mkForce false;
}

Then provision as usual from your private repo — machine0 provision <vm> ".#private" syncs the local flake to the VM, so nothing needs to be published.

Notes:

• The exported nixosModules require machine0.lib.mkSystem — they read machine0-specific specialArgs (nixpkgsUnstable, homeManager, inputs) and will not evaluate under a plain nixpkgs.lib.nixosSystem.
• The styled banner builder used by the built-in profiles is exported as machine0.lib.mkMotd ({ title, body ? [ ], width ? null } -> string; body lines: "" blank, "$ cmd" command, "# text" comment, "-> url" link, anything else plain). It is a plain function, not a module — to use it inside your profile.nix, pass it in from your flake: add { _module.args.machine0Lib = machine0.lib; } to your module list and take machine0Lib as a module argument.
• Inside your profile.nix, the inputs module arg is machine0's inputs. To use your own flake's inputs, pass them under a different name: add { _module.args.privateInputs = inputs; } to your module list.
• mkSystem is closed over this repo's locked inputs. Declaring your own nixpkgs input has no effect on it; to actually re-pin, use inputs.machine0.inputs.nixpkgs.follows = "nixpkgs" (not generally recommended — the agent inputs intentionally track their own nixpkgs, see flake.nix). To bump machine0 itself, run nix flake update machine0.
• /etc/nixos on the VM always contains the upstream machine0-nixos source (baked in for non-flake rebuilds). An in-VM sudo nixos-rebuild switch without your flake — like the nightly auto-upgrade — rebuilds the upstream profile and silently drops your private config. Rebuild by re-running machine0 provision <vm> ".#private" from your repo.
• nix build .#private produces a gzipped qcow2 image, same as the upstream profiles. Everything here is x86_64-linux; building the image (or the system) needs an x86_64-linux builder — evaluation works anywhere.