Basic Concepts

Thing Classes

The Internet is made up of "things", the most important concept to get to terms with when working with Watson IoT Platform is the idea of applications, devices, & gateways as three distinct classes of "thing" in your Internet of Things solution.

Getting your physical device model right is essential to building a solution that will allow you to take advantage of all the advanced capabilities of Watson IoT.


Applications are the most powerful class of thing in Watson IoT Platform.

  • Send events on behalf of devices
  • Send commands to devices
  • Recieve commands sent to devices
  • Work with the IBM Watson IoT Platform APIs


Applications are able to function as a gateway into the service, but should only be used as such when you view the gateway as an abstract entity in your solution rather than something physical to be managed on-site. If you assoicate the central point of contact with the platform as a specific piece of hardware it should be implemented as a gateway.


Applications capabilities vary wildly depending on the permissions granted to the application by the API key that it uses to connect. It is important to align the role granted to the API key used by the application to the capabilities of the application.


Devices are things that send data into the service (directly, or indirectly), and respond to commands directed at them.

  • Send events
  • Recieve commands


Devices in Watson IoT Platform are intended to mirror the physical deployment of hardware that will generate IoT data, regardless of whether it directly connects to the internet.


If you deploy 6 pieces of hardware each with seperate firmware, software, etc avoid the temptation to think that tracking these as individual devices has no value. Merging them into an "abstract device" representing all 6 when you register your physical device model in Watson IoT will make it more difficult to use advanced features of the platform as you explore Watson IoT Platform's advanced capabilities for device and data management.


Gateways are things that send data into the service, respond to commands, are able to send data from other devices, and relay commands to other devices.

  • Send events
  • Recieve commands
  • Send events on behalf of other devices
  • Recieve commands sent to other devices


Use gateways when you are developing a solution where multiple physical devices exist that will not each directly communicate with Watson IoT Platform, but instead will report to a local device, which serves as a central contact point to the service.

  • Each physical device should be registered to the platform as a device, even though it will not connect directly.
  • The central point of contact is your gateway.
  • The gateway should send multiple events on behalf of the local devices, rather than claiming ownership of the data by submitted the events as if the data came from the gateway itself.