---
name: system-architect
description: Sam's NixOS multi-machine infrastructure. Use for any task involving system config, cross-machine deployment, Docker, audio (Snapcast), MQTT (Mosquitto), NixOS flakes, Ubuntu, Sys Config, Nvim, Home Assistant.
compatibility: NixOS 25.11+, Home Manager, flakes
metadata:
  machines:
    - name: sam-4screen-desktop
      ip: 192.168.20.27
      type: Desktop
      os: "NixOS, Niri"
      role: Main dev machine. Sync to sam-ubuntu1.
      tech: Mainly terminal dev work with Nvim, Opencode, Pi dev code.
      hardware:
        cpu:
          model: "Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz"
          cores: 8
          threads: 8
        ram:
          total_gb: 62.7
        gpu:
          - i915
          - nvidia
        disks:
          - device: /dev/nvme0n1p2
            size: 869G
            mountpoint: /
          - device: efivarfs
            size: 256K
            mountpoint: /sys/firmware/efi/efivars
          - device: /dev/nvme0n1p1
            size: 1022M
            mountpoint: /boot
    - name: nixos-desktop
      type: Desktop
      ip: 192.168.20.13
      os: "NixOS, Niri"
      role: NixOS with Niri. Second dev. Web facing. Network scripts.
      tech: Docker (Mosquitto, N8N, Pi Hole back up with nebulasync from sam-ubuntu1 pihole, pocketbase, speech_piper, voice_bridge), websites at /var/www/, snapcast, gstreamer, librespot, mopidy
      hardware:
        cpu:
          model: "AMD Ryzen 5 5600 6-Core Processor"
          cores: 12
          threads: 12
        ram:
          total_gb: 15.5
        gpu:
        disks:
          - device: /dev/sdb2
            size: 907G
            mountpoint: /
          - device: efivarfs
            size: 128K
            mountpoint: /sys/firmware/efi/efivars
          - device: /dev/sdb1
            size: 1022M
            mountpoint: /boot
          - device: /dev/sdd1
            size: 2.7T
            mountpoint: /mnt/ubuntu_storage_3TB
          - device: /dev/sda2
            size: 1.9T
            mountpoint: /mnt/data
          - device: /dev/sdc2
            size: 932G
            mountpoint: /mnt/storage
    - name: sam-ubuntu1
      type: virtual machine
      ip: 192.168.20.35
      os: Ubuntu
      role: Ubuntu in Virtual Machine on Proxmox. Docker Machine for home network.
      tech: Mainly Docker
      hardware:
        cpu:
          model: "Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz"
          cores: 2
          threads: 2
        ram:
          total_gb: 14.2
        gpu:
        disks:
          - device: /dev/sda2
            size: 442G
            mountpoint: /
          - device: "//192.168.20.23/usb_3tb"
            size: 2.7T
            mountpoint: /mnt/nfs_usb_3tb
    - name: home-assistant
      type: virtual machine
      ip: 192.168.20.30
      os: Home Assistant OS
      role: Runs Home Assistant in a virtual machine on Proxmox Hypervisor
      tech: Home Assistant OS
    - name: file-server
      type: virtual machine
      ip: 192.168.20.23
      os:
      role: File server on Proxmox Hypervisor
      tech: File Server
    - name: proxmox-backup
      type: virtual machine
      ip: 192.168.20.48
      os: Proxmox Backup Server
      role: Runs standard proxmox backup server
      tech: Proxmox
    - name: proxmox
      type: hypervisor
      ip: 192.168.20.28
      os: Proxmox VE
      role: Hypervisor hosting all VMs (sam-ubuntu1 .35, file-server .23, home-assistant .30, proxmox-backup .48)
      tech: Web UI https://192.168.20.28:8006, SSH root@192.168.20.28
    - name: skinnyspeakers
      type: raspberry pi
      ip: 192.168.20.24
      os: Raspbian 12 (bookworm)
      role: Speaker/audio client, likely Snapcast speaker. Identified 2026-08-29 (was previously unknown .24)
      tech: SSH sam@192.168.20.24
    - name: sam-thinkpad
      type: Laptop
      ip: 192.168.20.51
      os: "NixOS, Niri"
      role: Portable dev laptop. Third pi machine. On-the-go + at home.
      tech: pi, Neovim, Home Manager. ThinkPad L14 Gen 2 AMD.
      hardware:
        cpu:
          model: "AMD Ryzen 5 PRO 5650U with Radeon Graphics"
          cores: 6
          threads: 12
        ram:
          total_gb: 14
        gpu:
        disks:
          - device: /dev/nvme0n1
            size: 238G
            mountpoint: /
  network:
    - sam-4screen-desktop has ssh keys to sam-ubuntu1 and nixos-desktop
    - "Gitea: Docker on .35 (gitea-server-1 + gitea-db-1) — web .35:3001, SSH .35:2222. pi-config repo: ssh://git@gitea.lab.audasmedia.com.au:2222/sam/pi-config.git"
    - "pi: Nix-managed pi-coding-agent 0.82.1 on all three (uniform); pi-tool-display global; pi-lsp-extension per-project"
    - "Each machine has its own ~/.agents clone of pi-config — a push from .27 does NOT auto-update .13/.51"
    - "DNS: Pi Hole on sam-ubuntu1 in docker"
    - "Reverse Proxy: Caddy on sam-ubuntu1 in docker"
    - "pihole main: sam-ubuntu1"
    - "pihole redundancy: nixos-desktop"
    - "Router Main: 192.168.20.1"
    - "Router Second: 192.168.20.254"
    - "Proxmox VE host: 192.168.20.28 (web UI :8006); PBS: 192.168.20.48 (:8007)"
    - "External IP: 144.6.86.11 (NOT 173.231.229.92 — that's InMotion's server)"
    - "Website: Audasmedia.com.au redirects to local *.lab.audasmedia.com.au"
---

# System Architect

Sam's NixOS multi-machine infrastructure reference.

## Machines

| Machine | IP | Type | OS | Role |
|---------|-----|------|-----|------|
| sam-4screen-desktop | 192.168.20.27 | Desktop | NixOS + Niri | Main dev machine |
| nixos-desktop | 192.168.20.13 | Desktop | NixOS + Niri | Second dev, web facing, Docker services |
| sam-thinkpad | 192.168.20.51 | Laptop | NixOS + Niri | Portable dev laptop |
| sam-ubuntu1 | 192.168.20.35 | VM | Ubuntu | Docker host for home network services |
| home-assistant | 192.168.20.30 | VM | HA OS | Home automation |
| file-server | 192.168.20.23 | VM | - | File server |
| proxmox-backup | 192.168.20.48 | VM | PBS | Proxmox backup server |
| proxmox | 192.168.20.28 | Host | Proxmox VE | Hypervisor — hosts all VMs (.23/.30/.35/.48), web UI :8006 |
| skinnyspeakers | 192.168.20.24 | Pi | Raspbian 12 | Speaker/audio client (Snapcast?) — identified 2026-08-29 |

## Network

- DNS: Pi Hole on sam-ubuntu1 (Docker), redundancy on nixos-desktop
- Reverse Proxy: Caddy on sam-ubuntu1
- Proxmox VE host: 192.168.20.28 (web UI :8006); PBS: 192.168.20.48 (:8007)
- Router: 192.168.20.1 (main), 192.168.20.254 (secondary)
- External IP: 144.6.86.11 (NOT 173.231.229.92 — that's InMotion's server)
- Website: audasmedia.com.au → *.lab.audasmedia.com.au

## Web Deploy Sync (.27 → .13)

- **Manual lsyncd** (not a service): config `~/.config/lsyncd/lsyncd.conf.lua` on .27 → rsync+ssh to `.13` `/var/www/<site>` (`delete = true`).
- Sites: `sprinklers` (zola/sprinkler/public), `sam-developer` + `sam-devops` (home_network/web_sites/*/dist) — see config for the full list.
- Permissions (.13): web folders use NixOS `users` group — new folders need `sudo chown -R sam:users /var/www/<folder>`.
- Secrets: `~/.config/environment.d/10-secrets.conf` (env keys, kept out of the git-tracked Nix store).

Full hardware specs are in the frontmatter metadata.

## Pi Agent (uniform across machines)

- **Binary**: nixpkgs `pi-coding-agent` 0.82.1 in `home.packages` on .27/.13/.51 (Nix-managed; npx wrapper + npm-global install removed 2026-08-05). Updates = nixpkgs flake bump + rebuild.
- **Assets**: `~/.agents` (git → Gitea `pi-config` on .35). Each machine has its OWN clone — update each machine's repo individually (`git -C ~/.agents pull`).
- **Global settings**: `~/.pi/agent/settings.json` — home.nix-managed on .27/.51; plain file on .13 (`chmod 600`, keys inline, outside any git repo). Same content: Gitea source (tavily-search, pi-config, pi-tool-display), skills (nixos-workflow), themes, prompts.
- **pi-tool-display**: global renderer (0 tools, 0 token cost). **pi-lsp-extension**: per-project via `/config-add ext pi-lsp-extension`. See `Obsidian → 350 AI → Pi Agent Extensions & Skills.md` for details.