Architecture · How Nexus works · Security · Privacy · AI-assisted development
Nexus isn't one program. She's a set of layers, each with one job, and each one only talks to the layer next to it. This page shows the shape of the system without drawing a map of the house network.
The layers
1. Where people meet her
- Voice, in the bedroom and the kitchen
- The wall tablet
- Phones and the iPad
- This website
- Email to Nexus
- A browser add-on on the main computer
2. Nexus herself
- Language model (her mind)
- Personality and household context
- Long-term memory
- Working out what you want
- Who's talking (voice prints)
- Safety and permission checks
3. Services she can use
- Home automation (lights, routines, scenes)
- Morning briefing and news
- Timers, reminders and notifications
- Email handling with a scanner
- Family chat and messages
- Web look-ups with privacy guards
4. Infrastructure
- The Hive: the AI server
- Mini Hive: the second voice
- Brain: the home automation platform
- Guardian: health, safety and the off switch
- A separated home network
- Nightly encrypted backups
The important rule between the layers
Nexus never touches a light switch, a door sensor or a camera directly. When she wants something done in the house, she asks the home automation platform to run a named, pre-approved action. Anything that isn't on that list simply doesn't exist from her point of view. Her words never turn into actions by themselves.
Technology, and why
| Job | What does it | Why |
|---|---|---|
| Her mind | An open-weight language model (Qwen3, 14 billion parameters), run locally with llama.cpp on a consumer graphics card | Runs entirely at home, fast enough to talk to, and swappable for a newer model later |
| Hearing | Whisper speech recognition, on the computer each speaker is plugged into | What you say is turned into text right there; the audio is never kept |
| Her voice | Piper text-to-speech, locally | Her own voice, no cloud voice service |
| Who's talking | A small voice-print model on the Hive | Tells Jeremy and Candice apart without a password, and only changes how she talks to you |
| Memory | A local database with vector search | She remembers the household without anything being stored outside the house |
| The house | Home Assistant | A mature, local home automation platform with a clear list of what Nexus may and may not ask for |
| The servers | Ubuntu Linux, small single-purpose services | Each piece can be tested, restarted or undone on its own |
| Phones, away from home | An encrypted private network for family devices | The family's phones reach Nexus from anywhere without opening the house to the internet |
| The tablet | A locked-down Android app | It runs only Nexus, and only installs updates whose signatures match a short approved list |
| This website | A static site on Cloudflare | Nothing on the public site connects back into the house |
Where guests fit
Visitors aren't placed on the household's trusted network. Guest Wi-Fi is kept apart from family devices and from the Hive's own services. Want the fun version? Read the rules for pilgrims.