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Fitbit SDK Guides

These resources will help you understand how to use each element of the Fitbit SDK. You’ll find guides for:

App Architecture

Explore the basic building blocks of a Fitbit app and how they fit together

User Interface

Learn about Fitbit SDK’s powerful rendering engine for creating beautiful user interfaces

Clock Faces

Learn how the Clock API handles tick events with the correct precision and timing


Learn how the companion API enhances Fitbit apps with an additional JavaScript runtime environment


Learn how to send and receive data or transfer files between Fitbit devices and mobile devices


Learn how to create a settings definition file so you can make your app configurable by users

Design Guidelines

Design clocks and apps for Fitbit with our system of visual styles and interactive components that are simple to use or modify


Learn how the Sensor APIs connect developers with the hardware sensors embedded in Fitbit devices

File System

Learn how the File System API allows developers to read and write files on the Fitbit device


Fitbit OS apps and clock faces must be granted permissions by the user, in order to use specific Device and Companion APIs


Learn how to use the Geolocation API to determine the physical location of a device using GPS


If you want to understand some of the terminology used in the guides, please read our Glossary