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Device Data Hub

Device Data Hub (DDH) is an on-device data exchange system built on a publish/subscribe (pub/sub) model. It lets applications and services on an Axis device share data with each other and with external consumers in a structured, decoupled way.

Whether you're building a native on-device application or integrating an external system, DDH gives you a consistent way to produce and consume data without tight coupling between components.

Key concepts​

Topics​

A topic defines a named data channel — for example, motion detection events or temperature readings. In DDH, topics are the core unit used to organize data exchange: publishers write data to a topic, and subscribers read from it.

Topic instances and keys​

A single topic can have multiple instances, each identified by keys. Keys let you distinguish between data sources of the same type. For example, a camera with multiple video channels might publish motion data on the same topic but with a different key per channel.

Available topics​

Axis devices publish data across a set of topics. The topics available on a given device depend on its capabilities, firmware version, and installed applications. Each topic has a defined data schema that describes the structure and fields of the data it carries.

Examples of topics an Axis device can produce include:

  • Analytics events
  • PTZ position and movement events

For the full list of topics, see the Data Hub Topics page.

How you can use DDH​

DDH supports three main integration paths depending on your use case:

Native on-device applications (ACAP)​

Use the ACAP framework to build native applications that run directly on the device. Your application can:

  • Produce data — publish data to a topic so other on-device components, ACAPs or external consumers can receive it.
  • Consume data — subscribe to topics to react to data published by other ACAPs or device subsystems.

External WebSocket API​

Connect an external system to the device over WebSocket to subscribe to topics and consume data in real time. Use this for server-side integrations, dashboards, or any system that needs a live data feed from the device.

Release history​

VersionWhat's new
Axis OS 12.11Initial release. ACAP SDK API, WebSocket API.

Next steps​

I want to…Go to
Build a native app that produces or consumes dataACAP API
Connect an external system over WebSocketWebSocket API
Browse available topics and their data schemasData Hub Topics