# Central AI Hub — System Overview

> **Writing Style**: ASD-STE100 Simplified Technical English (`ste-writing`).

## Purpose

The Hub is one service. Every way in reaches every ability through the Hub. Build
each ability once. All ways in get it.

Today, Jervis (voice) and dsh (chat) each understand the user and act. A third
way in, the phone app, would repeat the same work. The Hub stops this repeat.

## The Five Steps

1. **Hear** — take voice or text from any way in.
2. **Understand** — the LLM works out what the user asked.
3. **Check** — test whether the user may ask for this.
4. **Route** — send the request to one destination.
5. **Answer** — return a short reply in the right shape.

## Ways In

- Phone app (Kotlin) — wake word, voice, controls.
- Admin app (Kotlin) — restricted actions only.
- ESP32 voice — "Hey Jervis".
- dsh chat — per-person chat.
- Console portal — web dashboard.

## Destinations

| Destination | Job |
|---|---|
| Home Assistant | Lights, switches, timers, calendar. |
| Speakers (Jervis) | Speak and announce. |
| Internet control | Parental limits on kids' devices. |
| Artemis | Operate the phone screen. |
| Paperclip | Slow, multi-step, recorded work. |
| Web search | Tavily search. |
| Apprise / NTFY | Notifications and email. |

## Reply Shapes

The Hub returns one reply. The reply can hold text, spoken audio (TTS), Artemis
commands, a notification, or an email. TTS can play on the house speakers or on
the phone. The Hub returns the reply to the source.

## The Dividing Line

The Hub asks one question: does this need a decision, or does it need to happen?

- **Happen** — fast and certain. Go straight to the destination. No LLM in the
  path of the action.
- **Decision** — slow, multi-step, worth recording. Send to Paperclip.

## What the Hub Is Not

- Not a central brain. No single personality or memory.
- Not Paperclip. The Hub does not wait minutes for an answer.
- Not a destination. The Hub does not turn off the internet itself.