Volkswagen’s API transition has broken key open-source EV charging tools, disrupting smart charging and vehicle-data access while reigniting debates over data ownership, interoperability, and compliance with the EU Data Act.
Volkswagen’s vehicle API changes have disrupted major open-source EV charging platforms, preventing users from accessing vehicle charging and battery data needed for smart charging automation.
Users reported on May 27-28, 2026, that third-party tools could no longer authenticate with Volkswagen servers following the automaker’s transition to a new generation of vehicle interfaces. The disruption affected widely used open-source solutions, including Home Assistant integrations, EVCC (Electric Vehicle Charge Controller), and the Volkswagen Carnet integration for Home Assistant.
These tools enable smart charging, solar surplus charging, automated charging schedules, renewable-energy optimisation, and future vehicle-to-home and vehicle-to-grid use cases. EVCC, an open-source project hosted on GitHub, relies on real-time vehicle telemetry accessed through manufacturer APIs to optimise charging at home wallboxes.
The API shutdown also cut off direct access to vehicle-generated data that owners previously retrieved through independent applications, raising questions about whether motorists truly control data produced by their own vehicles.
Volkswagen had announced the change on April 2, 2026, stating it was “laying the foundation for a reliable and scalable charging data ecosystem” through a transition to new vehicle interfaces and the closure of the previous external interface from May 18.
The move sparked concerns that future access could require paid subscriptions or commercial intermediaries, although Volkswagen has not confirmed such plans.
Open-source developers have since reported partial success restoring access for some Audi and VW ID.3 vehicles, while users also reported that Tibber has integrated the new interface. However, functionality remains inconsistent.
The incident has intensified scrutiny of vehicle-data ownership and EU Data Act compliance. EVCC developers are now backing a petition calling for free and easy owner access to vehicle data, arguing that BMW remains the only major automaker offering customer-accessible vehicle data through its CarData portal.
