DOGKBD

A network keyboard proxy that lets a dog type on a rubber USB keyboard connected to a Raspberry Pi, with keystrokes routed over UDP to a Windows/Linux receiver for injection into any application. Built-in safety filtering, treat dispensing, and an OBS streaming overlay round out the system.

This is one piece of a larger project to get my dog to vibe code video games. The game made with it: Quasar Saz

How It Works

┌─────────────────┐        UDP broadcast        ┌─────────────────────────────┐
│  Raspberry Pi   │  ─────────────────────────>  │  Windows / Linux Receiver   │
│                 │       port 44555             │                             │
│  USB keyboard   │       16-byte packets        │  Keystroke injection        │
│  evdev → filter │       (2x for reliability)   │  OBS overlay (WebSocket)    │
│  → encode       │                              │  Treat dispenser (SSH)      │
└─────────────────┘                              │  Claude Code integration    │
                                                 └─────────────────────────────┘

1. Sender (Pi) reads the keyboard via evdev, filters through a safety allowlist, and broadcasts UDP packets
2. Receiver (Windows/Linux) deduplicates packets, re-checks the allowlist, and injects keystrokes into the selected target window via SendInput (Windows) or uinput (Linux)
3. An OBS overlay served on port 8080 shows typed keys in real time with pop-in animations
4. A treat dispenser rewards the dog via SSH command when typing thresholds are met

Safety

The system is designed around the principle that a dog should never be able to close a window, switch tabs, or trigger any dangerous key combination.

Double allowlist — keys are filtered at both sender and receiver. Only these HID codes pass:

Keys	HID Range
A–Z	0x04–0x1d
0–9	0x1e–0x27
Enter	0x28
Space	0x2c
Punctuation (-=[]\;',.`)	0x2d–0x37

Everything else is blocked: Escape, Tab, Ctrl, Alt, Meta, F-keys, and all other system keys. Remote Enter keys from the keyboard are also filtered out at the receiver — only auto-generated Enters are injected, with configurable timing.

Additional safety measures:

• Stateless tap events — press+release pairs only, no stuck keys possible
• Foreground-only injection — keystrokes only go to the selected target window when it has focus
• Packet deduplication — sequence number tracking prevents double injection from UDP retransmits
• Randomized device ID per sender session to handle restarts cleanly

Network trust warning: There is no encryption or authentication. The sender broadcasts keystrokes to the entire local network, and the receiver accepts any packet with valid DOGK framing. This is convenient for setup but means anyone on the same network can sniff keystrokes or inject fake ones (limited to the allowlisted keys above). Run on a trusted or isolated network.

Features

Receiver GUI

The receiver provides an egui desktop app with:

• Arm/disarm toggle — master switch for all keystroke injection
• Target window selector — pick which window receives keystrokes
• Key preview — scrollable display of the last 50 keys typed
• Input delay — configurable 0–5000ms buffer before injection

Automation

• Auto-enter on idle — automatically submits after 5s of no input (requires 16+ total chars and 4+ chars while Claude is idle)
• Periodic auto-enter — sends Enter every 15s while Claude Code is busy, nudging continued typing
• Busy-state cleanup — automatically backspaces buffered text if the dog types while Claude is processing

Claude Code Integration

The receiver exposes POST /claude-status on its web server port. A hook script sends {"status":"busy"} or {"status":"idle"} to coordinate automation features. On busy-to-idle transitions, the receiver plays a chime, focuses the target window, and resets treat tracking.

Treat Dispensing

When typing thresholds are met (16 total characters + 4 while Claude is idle), the receiver SSHs to a remote machine to trigger a treat dispenser — positive reinforcement for productive typing.

OBS Overlay

An HTML overlay served at http://localhost:8080 connects via WebSocket and displays each keystroke with a pop-in animation that fades after 6 seconds. Transparent background for easy OBS scene composition.

Project Structure

dogkbd/
  proto/      Shared protocol: packet encoding/decoding, HID allowlist (zero dependencies)
  sender/     Pi daemon: evdev keyboard reading, filtering, UDP broadcast
  receiver/   Windows/Linux GUI: injection, OBS overlay, treat dispenser, automation

Building

Requires Rust (edition 2024).

# Receiver (on Windows/Linux)
cargo build -p dogkbd-receiver --release

# Sender (on Raspberry Pi)
cargo build -p dogkbd-sender --release

Running

# Sender (requires sudo for evdev grab)
sudo ./target/release/dogkbd-sender --device /dev/input/dogkbd

# Receiver
./target/release/dogkbd-receiver --port 44555 --web-port 8080

Sender Options

Flag	Default	Description
-d, --device	/dev/input/dogkbd	evdev input device path
-p, --port	44555	UDP broadcast port
-b, --broadcast	255.255.255.255	Broadcast address
--duplicate	2	Packets sent per keystroke

Receiver Options

Flag	Default	Description
--port	44555	UDP listen port
--web-port	8080	HTTP/WebSocket server port

Protocol

16-byte little-endian UDP packets:

Offset	Size	Field
0	4	DOGK magic
4	1	Version (1)
5	1	Message type (1 = KeyTap)
6	4	Device ID
10	4	Sequence number
14	1	Modifiers (bit 0 = shift)
15	1	HID usage code

Related Projects

• Quasar Saz - The finished game made with this system, designed by Momo and developed by Claude Code (watch the video)
• tea-leaves - The base Godot project with all the tools and guardrails for making a game with Claude Code

License

MIT