Session counting and the af_app_opened event explained

Each time an app launches or displays in the foreground, the Appsflyer SDK sends the af_app_opened event. 

What is its purpose?

The af_app_opened event is used to count sessions. Session data can be found in the Activity dashboard.

The event provides advertisers with the ability to record and attribute sessions to a  media source and campaign. The event is sent as a postback to the ad network.

Sending af_app_opened to ad networks

No coding is required to implement the event since it is handled automatically by the Appsflyer SDK. It is available to networks supporting in-app events. The event value has no meaning. 

Due to the high frequency that the event occurs, sessions raw data is available via Data Locker only. It is not available using other data delivery tools. 


  • The af_app_opened event is a frequent event and may create a high volume of postbacks.
  • In-app events mapping > map all SDK events: mapping all events does not include af_app_opened.

Retargeting and af_app_opened

When existing users re-engage with an app, a re-engagement window opens. When the window is open,  events, including af_app_opened, are sent to both the original network and retargeting network.

In the case of Google Ads and Twitter, to avoid duplicate postbacks, the af_app_opened event is sent once.

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