# JavaScript SystemInfo Service API (WRT 1.0)

This SystemInfo Service API is supported since WRT 1.0.

The SystemInfo Service provides a set of system information services, allowing widgets to access a device's properties and to control certain device features. The SystemInfo Service API is implemented in a plug-in module and it is integrated into the WRT environment.

To use the SystemInfo APIs, each widget must load the plug-in module explicitly by defining the following HTML code in its main HTML document:

    <embed type="application/x-systeminfo-widget" hidden="yes"></embed>

Then the reference to the object must be retrieved via a JavaScript code as shown below:

    var sysinfo = document.embeds[0];

Note: In the code above, it is assumed that the embedded systeminfo is the first `embed` element in the HTML file.

Throughout the following sections where syntax and example codes illustrate the usage of the SystemInfo API, it is assumed that the plug-in module is loaded and the reference to the object is defined as `sysinfo` as implemented above.

The services provided by the plug-in SystemInfo API can be divided into seven main categories:

- Power information services

- Network information services

- Display and keypad illumination information and control services

- Vibration information and control services

- Beep tone control services

- Memory and file system information services

- System language information services