Read your car's CAN bus. Make sense of it. Never talk back to it.
Plug a USB CAN adapter into the OBD-II port and turn the raw torrent of frames into something you can actually read — which IDs are alive, which bytes move when you pull the handbrake, what the rev counter looks like as a number.
What it is
discodb² listens to the CAN traffic on your vehicle and helps you discover, decode and name the signals hiding in it. It is built for people who enjoy taking apart how their car works, on their own time, on a car they care about.
The bus is opened in listen-only/silent mode — enforced in the backend, independent of your network or UI. You can't accidentally transmit onto a live car.
A heavy cockpit client does the buffering and analysis on a laptop; a light copilot runs on a phone for a glance while the car moves. Same stream, two views.
Leave a Raspberry Pi in the car as a self-contained WiFi access point, or just run everything natively on your Mac, Linux box or Windows PC.
A built-in simulator emits a realistic VAG-style bus — revving RPM, ramping speed, draining fuel, plus counters and checksums to trip up naive analysis. Learn the tools before you touch a car.
How it works
The backend is a fast pass-through: it owns the adapter (listen-only), streams binary frames over a WebSocket, and records or replays them. The web clients use your machine's resources for buffering, decoding and analysis. The wire format is pinned in a written contract every component is built against.
Try it — no car, no adapter
Three commands bring up the backend on a realistic simulated bus and open the full cockpit in your browser. Swap one flag later for a real adapter.
# 1. Backend — stream a realistic simulated bus
cd backend && pip install -r requirements.txt
python -m discodb2_backend --source sim # ws://localhost:8765/ws
# 2. Cockpit — the full client, in another terminal
cd frontend/cockpit && npm install && npm run dev # http://localhost:5173
# 3. (optional) Copilot — the phone view
cd frontend/copilot && npm install && npm run dev
With a real adapter, swap --source sim for
--source gs_usb (candleLight/UCAN over libusb) or
--source socketcan (Linux/Pi).
Who it's for
A car is an expensive thing you look after. discodb² is built for the curiosity that comes with that — reading a bus to understand it, confirming a hypothesis against your own vehicle, decoding a signal nobody published. No telemetry, no accounts, no cloud. It runs on your hardware and listens. That's the whole pitch.