What it is
MIT-licensed reference firmware and BLE wire protocol for ESP32 “Hardware Buddy” devices that pair with Claude Cowork / Claude Code Desktop to show status and handle permission approvals.
Gabriel’s notes
Quick take: Anthropic published a surprisingly complete “hardware companion” reference: a BLE protocol + ESP32 firmware that turns Claude’s tool-permission prompts into something you can approve from a tiny physical gadget. I haven’t built one yet, but it’s exactly the kind of nerdy, slightly ridiculous interface experiment I can get behind.
anthropics/claude-desktop-buddy is an open-source GitHub repo that documents the “Hardware Buddy” Bluetooth Low Energy (BLE) wire protocol used by Claude’s desktop apps, and includes a working ESP32 “desk pet” example firmware. Claude for macOS and Windows can connect to maker devices over BLE to display permission prompts, recent transcript snippets, and other session interactions, and the repo points builders to REFERENCE.md if they only want the protocol (not the firmware). The BLE API is only available when the desktop apps are in developer mode, and it’s explicitly positioned as a maker/developer feature—not an officially supported product feature.
This is basically: “What if your AI agent had a Tamagotchi that lived off approvals?” The example device is a desk pet that sleeps when nothing’s happening, gets visibly impatient when an approval is pending, and lets you approve/deny tool-use requests from the device itself. The protocol also exposes lightweight session stats (running vs waiting), a short message string, token counters, and recent transcript lines—enough to make a companion UI feel alive without turning your desk into a mission control center.
I saved this under Robotics because it’s a clean, real-world bridge between agent software and a physical interface (and it comes with practical security guidance, which is rare in maker-land).
Good fit if you want to:
- Build a physical “approve/deny” button for Claude Code / Cowork tool calls (a safer vibe than blind auto-approve).
- Create a small status display for active sessions (running/waiting/idle) and recent activity.
- Prototype playful human-agent interfaces (desk pets, lamps, indicators, wearable widgets, etc.).
- Implement the protocol on your own hardware (Arduino, ESP32, nRF52, Raspberry Pi + BLE dongle).
- Learn a concrete, documented example of newline-delimited JSON over Nordic UART Service (NUS) on BLE.
Pricing snapshot (auto-enriched):
The repo itself is free and MIT-licensed. The Claude desktop app and Claude Code access may require a Claude plan and/or API usage, depending on how you’re using Claude (plan details can change; check the official pricing page). A third-party commercial “Claude Desktop Buddy” device exists with a published pre-order price of $99, but that’s separate from this open-source repo.
Work-use / compliance snapshot (auto-enriched):
This is a developer-mode feature and is stated to be “intended for makers and developers” and “isn’t an officially supported product feature.” The protocol can transmit transcript snippets and tool-call hints over BLE, so treat it like sensitive data: the docs warn that an unencrypted link can be sniffed by anyone nearby. The reference recommends LE Secure Connections bonding (encrypted-only characteristics) and also calls out basic defensive coding: if you accept the folder-push feature, validate file paths to avoid overwrites (reject .. / absolute paths unless you truly want that risk). Also note the repo’s license: the code is MIT, but some third-party GIF assets are explicitly not covered by the MIT license.
Alternatives (auto-enriched):
- Skip the firmware; implement the protocol yourself: Anthropic explicitly says you don’t need the code in the repo to build a device—just implement the BLE NUS + newline-delimited JSON protocol in
REFERENCE.md. This is better if you have custom hardware or want a cleaner codebase. - Buy instead of build: The third-party “Claude Desktop Buddy” product claims it ships devices running the upstream firmware from this repo. This is better if you want the gadget, not the hardware debugging hobby.
Before you adopt it:
- Decide up front: do you need the full “desk pet” UI, or just a minimal approval button + LED?
- Require encrypted pairing (LE Secure Connections) if you’re showing any transcript/tool details.
- If you enable folder-push, whitelist safe destination paths and reject path traversal.
Sources
- https://github.com/anthropics/claude-desktop-buddy
- https://github.com/anthropics/claude-desktop-buddy/blob/main/REFERENCE.md
- https://github.com/anthropics/claude-desktop-buddy/blob/main/LICENSE
- https://claude.com/pricing
- https://claude-desktop-buddy.com/