Token

How to retrieve a JWT (JSON Web Token) to authenticate on Cumulocity

Overview

In order to authenticate HTTP requests on Cumulocity, a device can retrieve a token using MQTT.

Retrieving the token

Follow the below steps in order to retrieve the token from the Cumulocity cloud using MQTT.

1. Subscribe to token topic

   tedge

   tedge mqtt sub 'c8y/s/dat'

   mosquitto

   mosquitto_sub -t 'c8y/s/dat'

   mqtt

   Subscribe: topic

   c8y/s/dat

2. Publish an empty message on c8y/s/uat topic

   tedge

   tedge mqtt pub 'c8y/s/uat' ''

   mosquitto

   mosquitto_pub -t 'c8y/s/uat' -m ''

   mqtt

   Publish topic

   c8y/s/uat

   Payload

   <<empty>>

3. After a while the token will be published on the subscribed topic c8y/s/dat in the below format

   71,${Base64 encoded JWT}