WiCAN Vehicle

What it does

WiCAN Vehicle gives your AI agent access to real-time vehicle data from any OBD-II compliant car, truck, or motorcycle through a meatPi WiCAN Pro adapter. The WiCAN plugs into the vehicle's OBD-II port and bridges CAN bus frames over WiFi to an MQTT broker — the MCP server subscribes to those topics.

Your agent can read standard OBD-II data (speed, RPM, fuel, coolant temperature, battery voltage), check and clear diagnostic trouble codes, and — with optional DBC file configuration — decode manufacturer-specific CAN data (door states, tyre pressures, EV battery SoC, steering angle).

Built on paho-mqtt for broker communication and cantools for DBC file parsing. Compatible with the opendbc community CAN database covering hundreds of vehicle models.

How it differs from cloud vehicle MCPs

	This plugin	Tesla / Tessie MCP	BMW CarData MCP
Vehicle support	Any OBD-II (1996+ US, 2001+ EU, 2005+ AU)	Tesla only	BMW/MINI only
Interface	Local hardware (OBD-II → WiFi → MQTT)	Cloud API	Cloud API
Auth required	MQTT broker credentials (local)	API key or OAuth	OAuth
Works offline	Yes (local network only)	No	No
Subscription cost	None (one-time hardware ~$40-50)	Tessie ~$5/mo	Free (EU only)
Remote commands	DTC clear, raw CAN send	Lock, climate, charge	Lock, climate, charge
Raw data access	Full CAN bus	Summary only	Summary only
Open source	Hardware + firmware + MCP	MCP only	MCP only

This is the only vehicle MCP that talks directly to hardware. Cloud MCPs give you manufacturer-curated data through proprietary APIs; WiCAN gives you raw bus access to whatever the vehicle broadcasts.

How it works

The WiCAN Pro is an ESP32-S3-based WiFi/BLE OBD-II adapter with native MQTT support. It connects to your WiFi network and publishes vehicle data to configurable MQTT topics. This MCP server subscribes to those topics via a local or remote MQTT broker.

No Bluetooth pairing. No serial ports. No USB drivers. Just MQTT.

Vehicle OBD-II port
    │
    ▼
WiCAN Pro (ESP32-S3, WiFi + BLE)
    │
    ▼ MQTT publish
MQTT Broker (Mosquitto / HA built-in)
    │
    ▼ MQTT subscribe
wican-blade-mcp

What data is available

Standard OBD-II PIDs (universal, any compliant vehicle):

• Engine RPM, vehicle speed, throttle position
• Coolant temperature, intake air temperature
• Fuel level, fuel system status, calculated engine load
• Battery voltage, oxygen sensor readings
• Diagnostic trouble codes (DTCs) and MIL status
• VIN (Vehicle Identification Number)
• Odometer (where supported by the vehicle)

Raw CAN bus (manufacturer-specific, requires DBC files):

• Door and window states, lock status
• Tyre pressures (TPMS)
• EV battery SoC, charging state, range estimate
• Steering angle, individual wheel speeds
• Gear position, ambient temperature
• Any data the vehicle puts on the CAN bus

Manufacturer-specific decoding uses DBC files from the opendbc project (comma.ai). Coverage varies by make/model — well-decoded for Honda, Toyota, Hyundai, GM, and many others.

Token efficiency

OBD-II responses are compact by nature — a PID response is a single value with a unit. The server formats state as pipe-delimited one-liners (SPEED | 60 km/h) with null-field omission, so only active data appears in the response.

Raw CAN frames are denser. The wican_can_read tool returns a bounded buffer (default 50 frames, max 200) with optional frame ID filtering. For continuous monitoring, configure the WiCAN firmware to poll only the PIDs you need rather than broadcasting the full bus — this reduces both MQTT traffic and token usage.

A typical wican_state response is 8–10 lines. A wican_diagnostics response with no active DTCs is 2 lines.

Network requirements

The WiCAN Pro needs to be on the same WiFi network as your MQTT broker, or configured to reach a cloud-hosted broker.

Home use (car in garage or driveway with WiFi coverage): works out of the box. The WiCAN connects to your home WiFi and publishes to your local Mosquitto or Home Assistant broker.

Third-party router setups (UniFi, pfSense, OPNsense): the WiCAN connects as a standard WiFi client — no special routing needed. Just ensure the MQTT broker is reachable from the WiFi VLAN the WiCAN joins.

Remote access (car parked away from home WiFi): requires a mobile hotspot, cellular-to-MQTT bridge, or a cloud MQTT broker (e.g. HiveMQ Cloud, EMQX Cloud). This is outside the scope of the plugin but documented in the WiCAN firmware docs.

Multi-vehicle setups: each WiCAN device gets a unique device ID. Set WICAN_DEVICE_ID to target a specific vehicle, or use multi_instance: true to run one MCP instance per vehicle with different MQTT topic filters.

The WiCAN Pro has sleep mode — it draws minimal power when the vehicle is off and reconnects automatically when the ignition is on.

Safety model

Read tools work immediately — vehicle state, diagnostics, trip data.

Write operations are dual-gated:

1. WICAN_WRITE_ENABLED=true environment variable (persistent, set in plugin config)
2. confirm=true parameter on each call (per-invocation, prevents accidental execution)

Both gates must pass. Your agent can inspect the vehicle freely but must be explicit about write operations.

Gated operations: clearing diagnostic trouble codes, sending raw CAN frames. Standard OBD-II reads and passive CAN monitoring are always safe.

CAN bus safety note: wican_can_send transmits arbitrary frames on the vehicle bus. Incorrect frames can cause ECU faults, warning lights, or unsafe behaviour. Use with extreme caution and only with known-good frame definitions. This tool is intended for diagnostics and research, not routine automation.

Hardware required

A meatPi WiCAN Pro (~$40-50 USD). Open-source hardware and firmware (meatpiHQ/wican-fw, 1.5k+ stars). Available from meatPi's website, Crowd Supply, and Tindie.

Variant	WiFi	BLE	Sleep Mode	Price
WiCAN Pro	Yes	Yes	Yes	~$45
WiCAN (original)	Yes	No	No	~$35

Both variants work with this plugin. The Pro is recommended for always-plugged-in use (sleep mode prevents battery drain).

Tool reference

Tool	Type	What it does
wican_vehicles	read	List connected WiCAN devices with vehicle identity and connection status
wican_state	read	Speed, RPM, fuel, coolant, battery voltage, throttle, engine load
wican_diagnostics	read	DTC codes, MIL status, freeze frame, monitor readiness
wican_battery	read	Battery voltage, alternator state, EV SoC (if CAN-decoded)
wican_trip	read	Speed, RPM, run time, odometer, fuel level
wican_can_read	read	Raw CAN frames from buffer, optional frame ID filtering
wican_dtc_clear	gated	Clear diagnostic trouble codes and reset MIL
wican_can_send	gated	Send a raw CAN frame to the vehicle bus