The condition flow object is used to evaluate expressions against the messages that pass through it.

Evaluate field Input area for the JavaScript expression. You can use ?input.keyname? in the code to access the input key elements from the input message. The JavaScript expression must evaluate to either true or false.
Output field Input area for the output message in JSON format. You can use ?input.keyname? to access the input key elements from the input message.
Example:

Evaluate field Simple Expression

Evaluate field Complex Expression Function

Output field