> For the complete documentation index, see [llms.txt](https://www.sdv.guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.sdv.guide/sdv101/part-c-building-blocks/building-blocks-of-an-sdv/service-oriented-architecture/vehicle-apis.md).

# Vehicle APIs

**Vehicle APIs** play a central role in modern **Software-Defined Vehicles (SDVs)** by enabling standardized access to vehicle data and functions. They simplify development, enhance interoperability, and support new services, driving innovation within the automotive ecosystem.

## Why Vehicle APIs Matter

Vehicle APIs matter because the offer Standardized Data and Function Access, Seamless Developer Integration, and Service Enablement and New Business Models:

1. **Standardized Data and Function Access**: Vehicle APIs allow developers to access essential vehicle data, such as sensor readings (e.g., vehicle speed or battery state of charge) and control actuators (e.g., moving mirrors, opening windows) in a consistent and standardized way.
2. **Seamless Developer Integration**: APIs abstract the complexities of underlying **E/E architectures** and automotive networks, enabling application developers to focus on creating features without requiring in-depth automotive engineering expertise.
3. **Service Enablement and New Business Models**: By facilitating easy access to vehicle functions, APIs unlock opportunities for **on-board** and **off-board services**, enhancing the vehicle experience and enabling ecosystem-driven business models such as personalized apps, remote diagnostics, and connected services.

## Key API Standards in the Automotive Domain

There are a number of key API standards emerging in the automotive domain, including:

1. **COVESA VSS (Vehicle Signal Specification)**: A signal-to-service API standard defining how vehicle signals are structured, enabling seamless data access and control through a tree-structured model.
2. **Android Automotive HAL (Hardware Abstraction Layer)**: Developed by Google, this API standard defines hardware abstraction for Android-based infotainment systems, ensuring consistent integration across different automotive hardware platforms.
3. **ISO 23150**: An international standard aimed at standardizing interfaces for **automated driving functions**, ensuring reliable communication between systems in the context of autonomous vehicle development.

Vehicle APIs are a key enabler for **connected services**, **software-defined platforms**, and **automotive innovation**, bridging the gap between complex vehicle systems and application developers while supporting scalable and interoperable automotive ecosystems.

## Example: digital.auto VSS Browser

The digital.auto VSS Browser is an open source, free to use tool to explore the COVESA VSS API catalogue. For example, in the following we show a part of the API catalogue in its original tree structure.

<figure><img src="/files/7VEzJVz46BiRSNqShhDN" alt=""><figcaption></figcaption></figure>

The VSS browser also allows for navigation of the COVESA VSS tree along the VSS catalogue structure. The following shows the catalogue root:

<figure><img src="/files/Vd2DWtZHm4xYCXYjMmhc" alt=""><figcaption></figcaption></figure>

When selecting a particular VSS signal, the details will be shown as follows:

<figure><img src="/files/A9XvePrQAEOPM3WquwVh" alt=""><figcaption></figcaption></figure>

Use the following link to try it out yourself:

{% embed url="<https://playground.digital.auto/>" %}