---
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title: Fire an Entry Event
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/marketing-cloud/guides/mc-apis/how-to-fire-an-event.md
canonical_url: https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/how-to-fire-an-event.html
source_site: developer.salesforce.com
content_type: documentation
content_hash: 43fab0e8d0b28ed0bddba1bd18b6a34047db63b7a95bb93def5812480e5af1eb
products:
  - Marketing Cloud Engagement APIs and Programmatic Languages
  - Marketing Cloud
---
# Fire an Entry Event

There are two ways to send events to Journey Builder:

- Using a Fire Event Activity in Automation Studio
- By POSTing an event to the Journey Builder API

To send events using the API:

1.  Define the event and its properties.
    - If you define the event in the web interface, note the event definition key.
    - If you define the event by using the API, use the POST /eventDefinition resource.
2.  Use a valid OAuth access token to authorize requests to REST API.
3.  Using the POST /events resource, POST the required fields and event properties to the API.

## Results

When an event is posted to the API, the data schema of the associated data extension validates that all fields from the API call exist in the data extension. The data extension associated with an event is defined in the DataExtensionID field in the EventDefinition table.

- If a field is missing, a validation exception is thrown.
- If the request is successful, an eventInstanceId is returned. This ID is a unique identifier for this specific request.

## Related Items

- _Salesforce Help_: [Fire Event Activity in Automation Studio](https://help.salesforce.com/articleView?id=mktg.mc_jb_fire_event.htm)
- [POST /eventDefinition Resource](https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/createEventDefinition.md)
- [POST /events Resource](https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/postEvent.md)