VW cuts owners' access to their own vehicle data with API change

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Due to a sudden change by Volkswagen, handling the manufacturer's electric cars has become more cumbersome recently. At the center is an Application Programming Interface (API) that users no longer have access to. However, this is necessary to obtain data from one's own vehicle.

Modern vehicles collect a lot of data and transmit it via telemetry to the vehicle manufacturers. For electric cars, their owners can, for example, query the battery charge status to optimize charging processes via a wallbox. This also enables network-friendly charging with surplus solar power during midday hours. With bidirectional charging via a wallbox, the electric car's battery could also be used as power storage for one's own house or even the power grid in the medium term.

A corresponding software offering for electric car drivers has emerged around this issue. For example, the Home Assistant solution can be used to control various systems, from refrigerators to photovoltaics, vehicles, surveillance, voice control, weather stations, and thousands of other possibilities.

EVCC suddenly non-functional

For electric vehicles, the EVCC (Electric Vehicle Charge Controller) module, as an add-on for Home Assistant, influences smart charging. This open-source solution is capable of controlling and optimizing the charging process of electric cars at private wallboxes. The software EVCC, provided on GitHub, supports various charging scenarios, including charging with surplus photovoltaic power (PV surplus charging), to increase the use of renewable energies and self-consumption.

To accomplish this, the third-party modules access the API of the respective vehicle manufacturers to query and evaluate the vehicle owner's data in real-time. There was also an API for Volkswagen Group vehicles to retrieve data after appropriate authentication. The software “Home Assistant Volkswagen Carnet” offered on GitHub made it possible to query data via the Volkswagen Connect Service and pass it on to Home Assistant. These solutions were used by owners of electric cars from VW, Audi, Cupra, Skoda, etc., to charge their batteries smartly.

VW advertises corresponding offers for buyers of its electric vehicles in the Volkswagen Connect Shop. There is also a dedicated app from VW, but it does not offer automation such as charging control.

VW API changed, third-party applications dead

On April 2, 2026, the Volkswagen Group published a little-noticed short news item titled “Technical Update: Transition to the next generation of vehicle interfaces.” The announcement stated that the Volkswagen Group was “laying the foundation for a reliable and scalable charging data ecosystem” and transitioning to a new generation of vehicle interfaces. The previous brand app interface for external access would be closed from calendar week 21, i.e., from May 18, it said.

On May 27 and 28, 2026, users of third-party solutions suddenly noticed that they could no longer establish a connection to the VW servers – authentication to the old VW brand API failed. The author of this article was contacted by affected individuals, who speculated that accessing one's own vehicle data might only be possible in the future with a paid “VW Connect Plus” subscription. It was also feared that VW might grant paid access to the API or only through third-party providers and operators of large electric vehicle fleets.

The author of this article documented the relevant status as of May 29, 2026, also based on reader reports, in his blog. Readers of heise online also contacted the editorial team in recent days with similar experiences.

First solutions found

Meanwhile, it is becoming apparent that the developers of the open-source solutions have found ways for successful authentication, allowing these tools to access the vehicles' charging data again. In a GitHub thread, a developer describes finding a method that works with his Audi electric vehicle. Another user confirms the functionality with a VW ID.3. However, there are reports that the approach still fails for other vehicles. So, this is all still “work-in-progress,” and whether it will work permanently and for free is uncertain.

Other users write in another GitHub thread that the “smart” electricity provider Tibber has apparently implemented an integration of the new VW interface. Users were thus able to retrieve at least some vehicle data in real-time.

EU Data Act, Right to Own Data, and a Petition

The API change at VW likely affects all vehicle brands of the group, from Audi, Bentley, Cupra, to Škoda and VW. The incident shows the power of vehicle manufacturers and raises the question of the vehicle owner's right to easily access their own data. The EU Data Act (Regulation (EU) 2023/2854), which is intended to regulate easy access to this data, has been in force since September 12, 2025.

The API change by the Volkswagen Group and the subsequent provision of vehicle data could, with a benevolent interpretation, be seen as the manufacturer's idiosyncratic implementation. This is because there is now a way to retrieve data from a VW vehicle via a web page. This data is then delivered as a ZIP archive within 24 hours – although this is not always adhered to. There is no real-time interface for querying charging data, nor easy access to the data, which was previously the case with direct API access.

The EVCC solution development team therefore wants to enforce compliance with the EU Data Act via a petition on change.org. According to the petition text, the background is that BMW is currently the only major manufacturer that makes vehicle data accessible to end customers via its CarData portal. Other manufacturers refuse corresponding requests or deny access completely – even though they would be legally obligated to do so. This petition aims to exert pressure on vehicle manufacturers to provide owners with free and easy access to vehicle data.

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