🔥 Hermes Wristband

A Hermes terminal you wear on your wrist.

Picture it: you're in the garden, hands in the soil, and an idea strikes. You glance down, tap a few keys on the little band wrapped around your wrist, and Hermes answers — right there on a screen the size of a postage stamp. No phone. No laptop. Just you, your thoughts, and a warm thread of WiFi connecting you to the Jetson humming away on your desk.

That's the dream this project chases, and it chases it with joy.

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What is this?

Hermes Wristband is a thin client: the band itself is an ultralight, WiFi-enabled microcontroller (an ESP32-S3-class part, a few grams, a few dollars) that does exactly three things — render text, send keystrokes, and hold a WebSocket open to the Jetson on your local network. All the heavy thinking, all the Hermes magic, happens on the Jetson where it belongs.

This repository is the Jetson-side reference implementation: a Python package that models the wristband's terminal, serves the WebSocket the band connects to, manages a Hermes subprocess per band, and exposes a tiny health endpoint the band can poll. Build the firmware, point it at this server, and you're wearing Hermes.

Why a wristband?

Because the best interface is the one that's already with you. Because a terminal you can't lose in a couch cushion is a terminal you'll actually use. Because there is something quietly wonderful about whispering to your AI companion from the produce aisle.

The hardware vision

Twenty testable prompts live in prompts/hardware_prompts.md, each one a hypothesis you can take to a workbench:

• The brain — ESP32-S3R8 for balance, ESP32-C6 for battery life, or a zero-solder LilyGo T-Display-S3 to get started this weekend.
• The screen — a crisp 1.69" IPS for daily wear, a sunlight-readable SHARP memory LCD for always-on glances, or a flexible e-ink panel that curves around your wrist for the full sci-fi effect.
• The keyboard — a 32-pad capacitive matrix for thinness, a 30-key snap-dome array for real tactile clicks, a stripped Rii i8+ for the impatient, or pure on-screen T9 for the minimalist.
• The power — a 400mAh pouch cell, a polite 100mA charger that won't warm your skin, and antenna placement that respects your metal watchband.

Every prompt is measurable: price, weight, milliamps, words-per-minute, milliseconds of latency. Bring a multimeter and a curious heart.

The software: ten modules, one happy family

Each module is small, tested, and does one thing well:

Module	What it does
config	Display profiles (40×12 IPS, 49×8 flex e-ink, …) and every tunable in one dataclass
terminal_model	A tiny scrollable cell buffer with proper VT-style wrap semantics
display_driver	Virtual framebuffer with damage-region tracking, so the band only redraws what changed
keyboard_mapper	Three physical layouts (matrix32 / dome30 / t9), layers, multi-tap
message_router	Key events → bytes: VT100 arrows, Ctrl-C, the works
wifi_link	mDNS advertise + discover, so the band finds hermes-wristband.local with no hardcoded IP
transport	One-band-at-a-time WebSocket server + test client
session_manager	Spawns a Hermes CLI per band in a real pty, sized to the band's screen
power_manager	Battery model: deep-sleep to active draw, dim-as-it-fades policy
health_server	GET /health and GET /config so the band can sync on connect
wristband_orchestrator	The conductor — wires them all together into one runnable server

Quick start

git clone https://github.com/drwjkirkpatrick-web/hermes-wristband.git
cd hermes-wristband
python3 -m pip install -e '.[net,dev]'
pytest -q          # 83 tests, all green

Run the server on your Jetson:

import asyncio
from hermes_wristband import wristband_orchestrator

async def main():
    orch = wristband_orchestrator.WristbandOrchestrator()
    await orch.start(advertise_mdns=True)   # band finds us as hermes-wristband.local
    await orch.run_forever()

asyncio.run(main())

The WebSocket listens on :9296, health on :9297. Point your band's firmware at ws://hermes-wristband.local:9296, send {"cmd":"new_session","argv":["hermes"]}, and start typing.

Status

Early days, bright eyes. The Jetson side is real and tested (83 passing tests, a genuine pty round-trip through /bin/cat standing in for Hermes). The firmware and the 3D-printed case are the next adventure — and the hardware prompts are the map.

Come build it with us. The wrist is warm, the WiFi is strong, and Hermes is waiting to say hello. 🔥

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Built with the Phosphorus personality — The Charismatic Communicator.