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Mediation (Legacy)

Add a custom event

We are currently rolling out changes to mediation. For details about these changes, refer to Updates to your Mediation page in AdMob.

Custom events let you set up waterfall mediation for an ad source that isn't a supported ad source. First, you'll need to implement a custom event adapter for the ad source you want to integrate. Use the instructions for Android or iOS.  Then, add the custom event in your mediation group using the following steps: 

  1. Sign in to your AdMob account at
  2. Click Mediation in the sidebar.
  3. Click the name of the mediation group. 
  4. Click Add custom event in the Waterfall ad sources table.
  5. Enter a descriptive label for the event.
  6. Enter a manual eCPM to use for this custom event. The eCPM will be used to dynamically position the event in the mediation chain where it will compete with other ad sources to fill ad requests.
  7. Click Continue.
  8. Enter a class name (required) and a parameter (optional) for each ad unit. Typically, the optional parameter contains an identifier that will be used by the custom event to load ads. 

    Note: If your class is implemented in Swift, you need to prefix the class name with the name of its app/framework module (for example, appName.className).

  9. Click Done.
  10. Click Save. The mediation group will be saved.
  11. If you haven't already implemented the custom event in your app's code, do so now using the same name, classes, and parameters you used to create it in AdMob.


Don't forget to use the Google Developers guide to implement your custom events in your app. If you don't complete this step, your custom events won't be able to fill incoming ad requests.

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