In MuleSoft, what is the function of a Listener?

In MuleSoft, a Listener acts as a trigger that waits for incoming messages. Its primary function is to receive these messages based on specific criteria such as an endpoint URL, port, or protocol. When a message arrives that meets the defined criteria, the Listener captures it and initiates further processing within the Mule application. This is essential for enabling event-driven architectures, where the application reacts to incoming requests or data.

Listeners are fundamental in the context of APIs and integration flows, ensuring that data can be processed in real-time as soon as it arrives. Other options in the question, while related to message handling, do not accurately describe the primary purpose of a Listener in MuleSoft.