Existing NixOS host

If your target machine already runs NixOS, applying hearth is a single rebuild against this flake.

Prerequisites

• The machine runs NixOS with flakes enabled.
• You have a hardware configuration for it (NixOS generates one at install time).
• You have your SSH public key. hearth disables SSH password auth.

1. Get the flake

Clone the repo onto the host, or reference it as a flake input from your own configuration.

git clone https://github.com/EricFinland/hearth
cd hearth

2. Add your SSH key

Edit nixos/hosts/workstation.nix and add your public key so you keep access after the rebuild:

hearth.adminKeys = [ "ssh-ed25519 AAAAC3Nz... you@laptop" ];

3. Rebuild

Apply the workstation configuration:

sudo nixos-rebuild switch --flake .#workstation

This creates a new generation. If anything breaks, roll back with sudo nixos-rebuild switch --rollback or pick a previous generation from the bootloader.

4. Verify

hearth-status

You should see Ollama active and the recent-runs section.

Note

The workstation host targets specific hardware (see nixos/hosts/workstation.nix). For different hardware, copy that host file and adjust the imports for your machine. The deep operational walkthrough lives in the Runbook.