The External Signal activity is used to organize and orchestrate different processes that are part of the same customer journey into different workflows. This activity can start one workflow from another. The External Signal activity can call a workflow and pass parameters, like an audience name to target, a file name to import, or a part of the message content, from one workflow to another. It can also call a REST API to integrate with external systems, like a content management system. With the Test activity, tests can be run on this functionality.
Learn how to configure External Signal activity to receive parameters** from an external system, customize a workflow with external parameters, and configure an end activity to call a workflow with the external parameters