Follow the instructions in the readme file in your PDK to install the drivers and platform Runtime. After that you can simply use the Stream Engine API that is included in the PDK package. The package also includes example code to make it easy to get going with writing applications for the eye tracker.

Easy migration of applications from 4C to 4L

Applications developed for the 4C eye tracker model using the Tobii Stream Engine can be used with the 4L without the need for the Tobii Core Software. Replacing the Tobii Core Software with a customized version of the platform software provides a slimmer and cleaner installation procedure with only the necessary parts included. Since the 4C and the 4L use the same APIs in the Tobii Stream Engine, it is easy to migrate applications from the 4C to the 4L.


When developing software for the 4L with the PDK, the development rights are governed by a Software Development License Agreement with Tobii. The eye tracking capabilities, also known as data streams, are separately licensed from Tobii (please see below for additional information).

Tobii Eye Tracker Data Streams

Different eye trackers from Tobii can have some differences in available data streams but this is the typical available data streams

 Data stream packageData stream
Core Data StreamsCombined (left & right eye) gaze point, filtered for interaction
User presence
Gaze origin
Head position (6DoF)
User position guide
Advanced data*Left and right eye separate unfiltered gaze point
Left and right eye separate unfiltered gaze origin
Left and right eye separate unfiltered pupil diameter
Configuration data*Screen calibration and display setup

*these data streams require a separate license key

Calibration of the eye tracker

The PDK package comes with a basic calibration application.

If you have the license for Configuration and Calibration data (see above) you can build your own calibration application if you have a need customization of the calibration. For details how go create your own calibration follow the instructions here:

calibration guidelines