Which type in the Cumulocity API is being modified, e.g. "measurement", "alarm", etc.
OptionaldestinationFor messages sent by data preparation, this is "cumulocity" by default, but can be set to other options for other destinations. For messages received by data preparation this is not set.
Since we usually don't know the C8Y ID to put in the payload, the data preparation rule can specify a single external ID to lookup (and automatically create if it does not exist). it is mandatory to include one item when sending this (unless the internal C8Y "id" is known and passed in the payload, or it's an operation where there's a dedicated field). When a Cumulocity message (e.g. operation) is received, this will contain a list of ALL external ids for this Cumulocity device.
A payload (similar to the WebSDK and/or to that uses in the C8Y REST/SmartREST API). Specialized by subinterfaces. Main difference is ID handling - when providing an externalSource you don't need to provide an "id" in the payload as you would in those APIs.
A create/update to a Cumulocity domain object.