//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.
`java -jar filter-processor-kafka-<version>.jar --spel.function.expression=toUpperCase()`
Change kafka to rabbit if you want to run it against RabbitMQ.
=== Payload
The incoming message can contain any type of payload.
== Options
//tag::configuration-properties[]
$$spel.function.expression$$:: $$A SpEL expression to apply.$$ *($$String$$, default: `$$<none>$$`)*
//end::configuration-properties[]
//end::ref-doc[]
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