vw-euda-mqtt

A standalone Python asyncio daemon that pulls VW ID.3 vehicle data from the VW EU Data Act portal and publishes it to MQTT with Home Assistant MQTT Discovery.

Repo: https://github.com/jochen/vw-euda-mqtt

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Background

On 2026-06-01 Volkswagen retired the classic VW-ID OAuth client (a24fba63-…). The identity provider at identity.vwgroup.io now returns HTTP 403 for every reverse-engineered login. weconnect, volkswagencarnet, CarConnectivity, and evcc are all broken the same way — there is no fix.

Under EU Regulation 2023/2854 (EU Data Act, in force since 2025-09-12) VW must provide vehicle data in a machine-readable format. The EU Data Act portal delivers read-only JSON snapshots on a 15-minute interval. This daemon uses that portal as its data source.

The original WeConnect-based soc_to_mqtt.py is kept in the repository as historical reference; it no longer works.

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What it does

The daemon runs three concurrent asyncio tasks:

1. VW poll — authenticates to the portal via OIDC, maintains a persisted cookie jar, polls the data-delivery list on an adaptive ~15-minute cadence, downloads each new dataset, and publishes curated sensors to MQTT with Home Assistant Discovery under MQTT_BASE_TOPIC (default ohm/car/id3).

2. evcc listener — subscribes to evcc's own MQTT topics (charging, connected, chargedEnergy on the configured loadpoint) to track real-time charging state and session energy.

3. SOC interpolation — between VW's 15-minute readings, estimates a live SOC anchored to the last real VW reading plus evcc's session energy:

   soc_live = anchor_soc + chargedEnergy_Wh / (capacity_kWh × 1000) × 100
   

   Published to <base_topic>/soc_live (configurable). The raw VW SOC on <base_topic>/soc is never modified. Each new VW dataset re-anchors the estimate, so drift self-corrects every ~15 minutes.

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Published MQTT topics and Home Assistant entities

All topics are under MQTT_BASE_TOPIC (default ohm/car/id3). HA Discovery configs are published to homeassistant/sensor/… and homeassistant/binary_sensor/….

Subtopic	HA name	Type	Device class
soc	SOC	sensor	battery
target_soc	Ziel-SOC	sensor	battery
charge_power_kw	Ladeleistung	sensor	power
charge_rate	Laderate	sensor	—
charge_energy_kwh	Geladene Energie	sensor	energy
remaining_charge_time_s	Restladezeit	sensor	duration
charge_state	Ladestatus	sensor	—
charge_type	Ladetyp	sensor	—
odometer_km	Kilometerstand	sensor	distance
range_km	Reichweite	sensor	distance
battery_temp_min_c	Akku-Temp Min	sensor	temperature
battery_temp_max_c	Akku-Temp Max	sensor	temperature
locked	Verriegelt	binary_sensor	lock
parking_brake	Handbremse	binary_sensor	—
soc_live	SOC (live)	sensor	battery

All messages are published with retain=True.

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Requirements

• Python 3.9+
• A VW-ID / myVolkswagen account linked to the EU Data Act portal
• An MQTT broker (e.g. Mosquitto)
• Home Assistant with the MQTT integration enabled (optional, for Discovery)

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Portal one-time setup

This is a manual, per-user step done once in a browser:

1. Log in at https://eu-data-act.drivesomethinggreater.com/ with your VW-ID credentials.
2. Go to Data clusters → Vehicle overview and link your car.
3. Click "Get customised data", choose continuous frequency and set the interval to 15 minutes.
4. Submit. The first datasets can take several hours to appear.

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Installation

git clone https://github.com/jochen/vw-euda-mqtt.git
cd vw-euda-mqtt

python3 -m venv venv
./venv/bin/pip install -r requirements-euda.txt

cp .env.example .env
nano .env   # fill in credentials and MQTT settings

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Configuration

Copy .env.example to .env. All variables:

Variable	Default	Description
VW_USERNAME	—	VW-ID email (alias for EUDA_EMAIL)
VW_PASSWORD	—	VW-ID password (alias for EUDA_PASSWORD)
EUDA_EMAIL	—	Portal email (takes precedence over VW_USERNAME)
EUDA_PASSWORD	—	Portal password (takes precedence over VW_PASSWORD)
VW_VIN / EUDA_VIN	first vehicle	VIN — only needed with multiple linked vehicles
EUDA_COUNTRY	si	OIDC state country code; try de if login fails
EUDA_LANGUAGE	sl	OIDC state language code; try de if login fails
MQTT_BROKER	localhost	MQTT broker hostname or IP
MQTT_PORT	1883	MQTT broker port
MQTT_BASE_TOPIC	ohm/car/id3	Root topic for all published values
MQTT_USER	—	MQTT username (optional)
MQTT_PASSWORD	—	MQTT password (optional)
EVCC_BASE_TOPIC	ohm/evcc	Base topic where evcc publishes
EVCC_LOADPOINT	1	evcc loadpoint number to subscribe to
VEHICLE_CAPACITY_KWH	58	Usable battery capacity in kWh (ID.3 Pro = 58)
SOC_LIVE_SUBTOPIC	soc_live	Subtopic for the interpolated SOC value
INTERP_INTERVAL_S	60	How often (seconds) to recalculate and publish soc_live
CHARGE_EFFICIENCY	1.0	Charging efficiency factor for interpolation (e.g. 0.92)

Account lockout warning. The daemon persists its session cookie and only re-authenticates on an explicit 401/403 response. Do not wrap it in a tight retry loop — repeated failed logins can lock your VW account.

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Running

One-shot connectivity test

./venv/bin/python euda_probe.py

This logs in, lists vehicles, and prints the first available dataset — useful to confirm credentials and portal access before starting the daemon.

Foreground (manual test)

./venv/bin/python euda_service.py

systemd user service (recommended)

See systemd/README.md for full instructions. Quick summary:

mkdir -p ~/.config/systemd/user
cp systemd/vw-euda-mqtt.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now vw-euda-mqtt

# Persist across reboots without login:
loginctl enable-linger pi

Logs:

journalctl --user -u vw-euda-mqtt -f

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evcc integration

Point evcc at ohm/car/id3/soc_live via a custom MQTT vehicle. This topic is non-retained and republished every INTERP_INTERVAL_S (60 s), so a short evcc timeout reliably flags the SOC as stale if this service stops — evcc then won't keep charging against a frozen value. Use the live topic, not the raw soc (which is retained for HA display and would linger after an outage).

mqtt:
  broker: 192.168.1.10:1883

vehicles:
  - name: id3
    type: custom
    title: VW ID.3
    capacity: 58              # kWh (ID.3 Pro)
    soc:
      source: mqtt
      topic: ohm/car/id3/soc_live   # non-retained, refreshed every 60 s
      timeout: 10m                  # short: soc_live is fresh; older ⇒ service down

No extra publishing is required — MQTT is pub/sub and the daemon already publishes the topic.

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License

MIT