This is gr0m's fork of Anthropic's
claude-desktop-buddy, licensed MIT (Copyright 2026 Anthropic, PBC — see LICENSE). The upstream project is a reference implementation of a BLE desk pet for Claude; this fork keeps that intact and adds networking, a Claude Code bridge, and an MCP control surface (see What this fork adds).
Building your own device? You don't need any of the code here. See REFERENCE.md for the wire protocol: Nordic UART Service UUIDs, JSON schemas, and the folder push transport.
Claude for macOS and Windows can connect Claude Cowork and Claude Code to maker devices over BLE, so developers and makers can build hardware that displays permission prompts, recent messages, and other interactions.
As an example, the upstream project built a desk pet on ESP32 that lives off permission approvals and interaction with Claude. It sleeps when nothing's happening, wakes when sessions start, gets visibly impatient when an approval prompt is waiting, and lets you approve or deny right from the device.
The mascot in this fork is the gr0m 3D vector robot: a boxy head cube and chest cube rendered through a real 3×3 rotation matrix, with accelerometer-driven parallax so the robot appears to turn and look around as you tilt the device. A horizontal visor stripe carries the mood channel, and the robot moves through the same set of mood states as the original pet (sleep, idle, busy, attention, celebrate, dizzy, heart).
📖 Full illustrated manual: docs/manual.html
This fork extends the upstream BLE-only desk pet with networking and a control/automation surface. The capabilities below are what's shipped today — for setup details see tools/cc-bridge/README.md.
- WiFi + WireGuard networking. The BLE stack was migrated from Bluedroid to NimBLE, which frees ~30–40 KB of heap so WiFi + WireGuard and BLE can coexist on the M5StickC Plus's single-radio ESP32.
- Radio is WiFi xor BLE (they share the 2.4 GHz radio); serial is
always available regardless of mode. Switch via the Settings menu or with
{"cmd":"radio","mode":"wifi"|"bt"|"off"}. - The
tools/cc-bridgedaemon lets Claude Code — both the CLI and the Code feature inside the desktop app — show permission prompts on the device and approve/deny with the physical buttons. It works over four transports: USB serial, local BLE, WiFi on the same LAN, and WiFi + VPN (WireGuard) for remote reach. See tools/cc-bridge/README.md for setup. - The gr0m MCP server (
tools/cc-bridge/gr0m_mcp.py) exposes the device to Claude as MCP tools: status, on-screen notify, radio mode, owner name, token usage / reporting period / reset, GPIO read/write/mode, ADC read, and a single-channel logic-analyzer capture, plus adapter mode — which turns the device into a dedicated GPIO probe. - Token-usage reporting on the device. The daemon computes output-token usage over a configurable window (day / week / month / all) from your Claude Code transcripts and pushes it to the device for display. Approvals and denials are tracked per period alongside it.
- Character evolution + on-device menus. The gr0m mascot assembles itself across five lifetime-usage milestones (1M → 250M tokens) — from a bare head to the full rig (flat-shaded early, dynamically lit once mature). On-device menus, opened with a long-press of A on the matching info page, cover a Connection screen (WiFi / BT / Off / Adapter) and a Usage screen (reporting window, plus reset-counters and reset-buddy-level).
- DJ mode — the end-game upgrade. It's not a toggle: once the character reaches the final evolution stage (Stage 5, 250M lifetime tokens) it breaks into a full-detail DJ-booth scene on its own (turntables, mixer, VU-meter visor, headphones, note particles on an internal beat) — during celebrations and the occasional idle flourish. Earned, not switched on.
Design notes: docs/superpowers/specs/ has the full evolution / DJ / menu design spec.
The redesigned device screens (approval prompt, pet stats, clock, menus,
pairing) and the gr0m character's mood/evolution states. A live, interactive
version of this showcase is published via GitHub Pages (see
index.html).
gr0m assembles itself as your lifetime token usage grows — a new stage every
~250K tokens — ending in the Stage-5 "human disguise" (a robot unconvincingly
cosplaying a person). The PET screen's Evolution page cycles through every
stage live on the device. Each stage is rendered pixel-exact off-device by
tools/render, which compiles the real character code against
host stubs.
The firmware targets ESP32 with the Arduino framework. As written, it depends on the M5StickCPlus library for its display, IMU, and button drivers—so you'll need that board, or a fork that swaps those drivers for your own pin layout.
Install PlatformIO Core, then:
pio run -t uploadThe build uses NimBLE (h2zero/NimBLE-Arduino) instead of the default
Bluedroid stack — it's already declared in platformio.ini, so PlatformIO
pulls it on first build along with the WireGuard-ESP32 dependency. No extra
setup is needed.
If you're starting from a previously-flashed device, wipe it first to clear stale NVS:
pio run -t erase && pio run -t uploadOnce running, you can also wipe everything from the device itself: hold A → settings → reset → factory reset → tap twice.
To pair your device with Claude, first enable developer mode (Help → Troubleshooting → Enable Developer Mode). Then, open the Hardware Buddy window in Developer → Open Hardware Buddy…, click Connect, and pick your device from the list. macOS will prompt for Bluetooth permission on first connect; grant it.
Proof-of-concept mockup: a reimagined "maker dashboard" take on this window — live device mirror, today's metrics, a live permission prompt, an activity stream, the character library, and device tools — is in
docs/buddy-dashboard.html. This is a static proof-of-concept mockup of the desktop companion, not a real or working app.
Once paired, the bridge auto-reconnects whenever both sides are awake.
If discovery isn't finding the stick:
- Make sure it's awake (any button press)
- Check the stick's settings menu → bluetooth is on (remember: the radio is WiFi xor BLE — if it's in WiFi mode, BLE discovery won't see it)
| Normal | Pet | Info | Approval | |
|---|---|---|---|---|
| A (front) | next screen | next screen | next screen | approve |
| B (right) | scroll transcript | next page | next page | deny |
| Hold A | menu | menu | menu | menu |
| Power (left, short) | toggle screen off | |||
| Power (left, ~6s) | hard power off | |||
| Shake | dizzy | — | ||
| Face-down | nap (energy refills) |
The screen auto-powers-off after 30s of no interaction (kept on while an approval prompt is up). Any button press wakes it.
In addition to the gr0m vector robot, the firmware ships the upstream set of ASCII pets, each with seven animations (sleep, idle, busy, attention, celebrate, dizzy, heart). Menu → "next pet" cycles them with a counter. Choice persists to NVS.
If you want a custom GIF character instead of a built-in buddy, drag a character pack folder onto the drop target in the Hardware Buddy window. The app streams it over BLE and the stick switches to GIF mode live. Settings → delete char reverts to the built-in mode.
A character pack is a folder with manifest.json and 96px-wide GIFs:
{
"name": "bufo",
"colors": {
"body": "#6B8E23",
"bg": "#000000",
"text": "#FFFFFF",
"textDim": "#808080",
"ink": "#000000"
},
"states": {
"sleep": "sleep.gif",
"idle": ["idle_0.gif", "idle_1.gif", "idle_2.gif"],
"busy": "busy.gif",
"attention": "attention.gif",
"celebrate": "celebrate.gif",
"dizzy": "dizzy.gif",
"heart": "heart.gif"
}
}State values can be a single filename or an array. Arrays rotate: each loop-end advances to the next GIF, useful for an idle activity carousel so the home screen doesn't loop one clip forever.
GIFs are 96px wide; height up to ~140px stays on a 135×240 portrait screen.
Crop tight to the character — transparent margins waste screen and shrink
the sprite. tools/prep_character.py handles the resize: feed it source
GIFs at any sizes and it produces a 96px-wide set where the character is the
same scale in every state.
The whole folder must fit under 1.8MB —
gifsicle --lossy=80 -O3 --colors 64 typically cuts 40–60%.
See characters/bufo/ for a working example.
If you're iterating on a character and would rather skip the BLE round-trip,
tools/flash_character.py characters/bufo stages it into data/ and runs
pio run -t uploadfs directly over USB.
| State | Trigger | Feel |
|---|---|---|
sleep |
bridge not connected | eyes closed, slow breathing |
idle |
connected, nothing urgent | blinking, looking around |
busy |
sessions actively running | sweating, working |
attention |
approval pending | alert, LED blinks |
celebrate |
level up (every 50K tokens) | confetti, bouncing |
dizzy |
you shook the stick | spiral eyes, wobbling |
heart |
approved in under 5s | floating hearts |
src/
main.cpp — loop, state machine, UI screens
buddy.cpp — ASCII species dispatch + render helpers
buddies/ — one file per species (incl. gr0m), seven anim functions each
ble_bridge.cpp — Nordic UART service (NimBLE), line-buffered TX/RX
net_wifi.cpp — WiFi + WireGuard transport, TCP listener / dial-out
character.cpp — GIF decode + render
data.h — wire protocol, JSON parse
xfer.h — folder push receiver
stats.h — NVS-backed stats, settings, owner, species choice
characters/ — example GIF character packs
tools/ — generators, converters, and the cc-bridge daemon + MCP server
The BLE API is only available when the desktop apps are in developer mode (Help → Troubleshooting → Enable Developer Mode). It's intended for makers and developers and isn't an officially supported product feature.
Found a vulnerability? See SECURITY.md for how to report it privately.