> For the complete documentation index, see [llms.txt](https://docs.digibee.com/documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.digibee.com/documentation/connectors-and-triggers/triggers/messaging-and-events/event.md). # Event Trigger Discover more about the Event Trigger and how to use it on the Digibee Integration Platform. The **Event Trigger** enables event-driven communication between pipelines, starting a pipeline's execution automatically in response to a specific event published by another pipeline through the [**Event Publisher**](/documentation/connectors-and-triggers/connectors/queues-and-messaging/event-publisher.md) connector. Learn more about [how to use event-driven architecture on the Digibee Integration Platform](/documentation/resources/use-cases/how-to-use-event-driven-architecture-on-the-digibee-integration-platform.md). ## **Parameters** Configure the trigger using the parameters below.
ParameterDescriptionTypeDefault
Event NameThe name of the event the trigger responds to.Stringevent-trigger
ExpirationThe time, in milliseconds, that the event remains in the queue. If the value is 0 or greater than 6 hours, the expiration is set to 1/4 of the value configured in Maximum Timeout.Integer600000
Maximum TimeoutThe maximum time, in milliseconds, that the pipeline can take to process the event before returning a response. Maximum limit: 900000.Integer30000
Allow Redelivery of MessagesWhen enabled, allows messages to be redelivered if a failure occurs in the Pipeline Engine.Booleanfalse
DocumentationOptional field to describe the trigger configuration and any relevant business rules.StringN/A
## **How does event-based messaging between pipelines work?** An event-driven setup always has two sides: a pipeline that publishes the event and one or more pipelines that consume it. First, configure the Publisher pipeline: 1. Add the [Event Publisher](/documentation/connectors-and-triggers/connectors/queues-and-messaging/event-publisher.md) connector to the pipeline. 2. In the **Event** parameter, enter the name of the event to publish. 3. To send data with the event, define the payload in the **Body** parameter. Then, configure the Subscriber pipeline: 1. Set the pipeline's trigger type to Event Trigger. 2. In the trigger configuration, enter the event name in the **Event Name** property. This value must match the one set in the **Event** parameter of the Publisher pipeline. With both pipelines configured, every time the Publisher pipeline runs and publishes the event, the Subscriber pipeline is triggered and starts running automatically. {% hint style="warning" %} #### Note on redeploying Publisher and Subscriber pipelines When redeploying a pipeline with Event Publisher, also redeploy the corresponding Subscriber pipeline (the one with the Event Trigger), starting with the Subscriber. If the two sides are temporarily misaligned, event delivery keeps working, but the timeout and redelivery (Allow Redelivery Of Messages) settings may not apply until both pipelines are redeployed. Learn more in [How to interpret event publishing and delivery alerts](/documentation/troubleshooting/deployment-issues/interpret-event-publishing-and-delivery-alerts.md). {% endhint %} ## **Messages flow** #### **Input** The trigger expects a valid message in JSON format. The received message corresponds exactly to the content defined in the `body` attribute of the Event Publisher connector. ```json { "id": "1", "description": "Description of the case" } ``` #### **Output** The connector forwards the message received from the previous connector without making any changes. Based on the example above, the connector forwards: ```json { "id": "1", "description": "Description of the case" } ``` ## **Limitations** ### **Event routing limits** To protect the messaging infrastructure and prevent infinite loops or excessively long chains that could degrade system performance, the Event Trigger enforces an event routing limit. When an event triggers a chain of other events (for example, a pipeline triggered by an Event Trigger publishes a new event that triggers the same Event Trigger again), the system tracks the number of chained events. If this count reaches the default limit of 25 events, the system interrupts processing of the current event. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.digibee.com/documentation/connectors-and-triggers/triggers/messaging-and-events/event.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.