Custom events let you add waterfall mediation for an ad network that isn't a [supported ad network](https://developers.google.com/admob/android/choose-networks.md.txt). You do this by implementing a custom event adapter for the ad network you want to integrate. You can find a full sample custom event project in our [GitHub repo](https://github.com/googleads/googleads-mobile-android-mediation). ## Prerequisites Before you can create custom events, you must first integrate one of the following ad format into your app: - [Banner](https://developers.google.com/admob/android/banner.md.txt) - [Interstitial](https://developers.google.com/admob/android/interstitial.md.txt) - [Native](https://developers.google.com/admob/android/native.md.txt) - [Rewarded](https://developers.google.com/admob/android/rewarded.md.txt) ## Create a custom event in the UI A custom event must first be created in the AdMob UI. See the instructions in [Add a custom event](https://support.google.com/admob/answer/3083407). You need to supply the following: Class Name : The fully-qualified name of the class that implements the custom event adapter---for example, `com.google.ads.mediation.sample.customevent.SampleCustomEvent`. As a best practice, we recommend using a single adapter class for all custom event ad formats. Label : A unique name defining the ad source. Parameter : An optional string argument passed to your custom event adapter. ## Initialize the adapter When Google Mobile Ads SDK (Legacy) initializes, `initialize()` is invoked on all supported third-party adapters and custom events configured for the app within the AdMob UI. Use this method to perform any necessary setup or initialization on the required third-party SDK for your custom event. ### Java ```java package com.google.ads.mediation.sample.customevent; import com.google.android.gms.ads.mediation.Adapter; import com.google.android.gms.ads.mediation.InitializationCompleteCallback; import com.google.android.gms.ads.mediation.MediationConfiguration; public class SampleAdNetworkCustomEvent extends Adapter { private static final String SAMPLE_AD_UNIT_KEY = "parameter"; @Override public void initialize(Context context, InitializationCompleteCallback initializationCompleteCallback, List mediationConfigurations) { // This is where you will initialize the SDK that this custom // event is built for. Upon finishing the SDK initialization, // call the completion handler with success. initializationCompleteCallback.onInitializationSucceeded(); } } ``` ### Kotlin ```kotlin package com.google.ads.mediation.sample.customevent import com.google.android.gms.ads.mediation.Adapter import com.google.android.gms.ads.mediation.InitializationCompleteCallback import com.google.android.gms.ads.mediation.MediationConfiguration class SampleCustomEvent : Adapter() { private val SAMPLE_AD_UNIT_KEY = "parameter" override fun initialize( context: Context, initializationCompleteCallback: InitializationCompleteCallback, mediationConfigurations: List ) { // This is where you will initialize the SDK that this custom // event is built for. Upon finishing the SDK initialization, // call the completion handler with success. initializationCompleteCallback.onInitializationSucceeded() } } ``` ## Report version numbers All custom events must report to Google Mobile Ads SDK (Legacy) both the version of the custom event adapter itself and the version of the third-party SDK the custom event interfaces with. Versions are reported as [`VersionInfo`](https://developers.google.com/admob/android/reference/com/google/android/gms/ads/VersionInfo.md.txt) objects: ### Java ```java package com.google.ads.mediation.sample.customevent; public class SampleCustomEvent extends Adapter { @Override public VersionInfo getVersionInfo() { String versionString = new VersionInfo(1, 2, 3); String[] splits = versionString.split("\\."); if (splits.length >= 4) { int major = Integer.parseInt(splits[0]); int minor = Integer.parseInt(splits[1]); int micro = Integer.parseInt(splits[2]) * 100 + Integer.parseInt(splits[3]); return new VersionInfo(major, minor, micro); } return new VersionInfo(0, 0, 0); } @Override public VersionInfo getSDKVersionInfo() { String versionString = SampleAdRequest.getSDKVersion(); String[] splits = versionString.split("\\."); if (splits.length >= 3) { int major = Integer.parseInt(splits[0]); int minor = Integer.parseInt(splits[1]); int micro = Integer.parseInt(splits[2]); return new VersionInfo(major, minor, micro); } return new VersionInfo(0, 0, 0); } } ``` ### Kotlin ```kotlin package com.google.ads.mediation.sample.customevent class SampleCustomEvent : Adapter() { override fun getVersionInfo(): VersionInfo { val versionString = VersionInfo(1,2,3).toString() val splits: List = versionString.split("\\.") if (splits.count() >= 4) { val major = splits[0].toInt() val minor = splits[1].toInt() val micro = (splits[2].toInt() * 100) + splits[3].toInt() return VersionInfo(major, minor, micro) } return VersionInfo(0, 0, 0) } override fun getSDKVersionInfo(): VersionInfo { val versionString = VersionInfo(1,2,3).toString() val splits: List = versionString.split("\\.") if (splits.count() >= 3) { val major = splits[0].toInt() val minor = splits[1].toInt() val micro = splits[2].toInt() return VersionInfo(major, minor, micro) } return VersionInfo(0, 0, 0) } } ``` ## Request ad To request an ad, refer to the instructions specific to the ad format: - [Banner](https://developers.google.com/admob/android/custom-events/banner.md.txt) - [Interstitial](https://developers.google.com/admob/android/custom-events/interstitial.md.txt) - [Native](https://developers.google.com/admob/android/custom-events/native.md.txt) - [Rewarded](https://developers.google.com/admob/android/custom-events/rewarded.md.txt)