Receive tasks are tasks which references a message. They are used to wait until a proper message is received.
When a receive task is entered then a corresponding message subscription is created. The workflow instance stops at this point and waits until the message is correlated.
A message can published using one of the Zeebe clients. When the message is correlated, the receive task gets completed and the workflow instance continues.
An alternative to receive tasks are message intermediate catch events which behaves the same but can be used together with event-based gateways.
A message can be referenced by one or more receive tasks. It must define the name of the message (e.g.
Money collected) and the
correlationKey variable (e.g.
correlationKey variable must reference a variable of the workflow instance that holds the correlation key of the message. It is read from the workflow instance on activating the receive task and must be either a
string or a
In order to correlate a message to the receive task, the message is published with the defined name (e.g.
Money collected) and the value of the
correlationKey variable. For example, if the workflow instance has a variable
orderId with value
"order-123" then the message must be published with the correlation key
By default, all message variables are merged into the workflow instance. This behavior can be customized by defining an output mapping at the receive task.
A receive task with message definition:
<bpmn:message id="Message_1iz5qtq" name="Money collected"> <bpmn:extensionElements> <zeebe:subscription correlationKey="orderId" /> </bpmn:extensionElements> </bpmn:message> <bpmn:receiveTask id="money-collected" name="Money collected" messageRef="Message_1iz5qtq"> </bpmn:receiveTask>
Using the BPMN modeler
Adding a receive task with message:
Workflow instance records of a receive task:
|Intent||Element Id||Element Type|