//tag::ref-doc[]
= Transform Processor
Transformer processor allows you to convert the message payload structure based on a SpEL expression.
Here is an example of how you can run this application.
[source,shell]
....
java -jar transform-processor-kafka-<version>.jar \
--spel.function.expression=payload.toUpperCase()
....
Change kafka to rabbit if you want to run it against RabbitMQ.
== Payload
The incoming message can contain any type of payload.
== Options
https://github.com/spring-cloud/spring-functions-catalog/tree/main/function/spring-spel-function#configuration-options[See function catalog for configuration options]
//end::ref-doc[]
