Setup
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Custom events let you add waterfall mediation for an ad network that isn't a
supported ad network. 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.
Prerequisites
Before you can create custom events, you must first integrate one of the
following ad format into your app:
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.
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
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
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<MediationConfiguration> 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
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<MediationConfiguration>
) {
// 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
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
objects:
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
package com.google.ads.mediation.sample.customevent
class SampleCustomEvent : Adapter() {
override fun getVersionInfo(): VersionInfo {
val versionString = VersionInfo(1,2,3).toString()
val splits: List<String> = 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<String> = 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:
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2025-08-22 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-22 UTC."],[[["\u003cp\u003eCustom events allow you to add waterfall mediation for unsupported ad networks by implementing a custom event adapter.\u003c/p\u003e\n"],["\u003cp\u003eBefore creating custom events, you must integrate a supported ad format (Banner, Interstitial, Native, or Rewarded) into your app.\u003c/p\u003e\n"],["\u003cp\u003eYou need to create a custom event in the AdMob UI, providing the class name, label, and optional parameter.\u003c/p\u003e\n"],["\u003cp\u003eAll custom event adapters need to report both the adapter and third-party SDK versions to the Google Mobile Ads SDK using \u003ccode\u003eVersionInfo\u003c/code\u003e objects.\u003c/p\u003e\n"],["\u003cp\u003eRefer to format-specific instructions to request an ad after implementing the custom event adapter.\u003c/p\u003e\n"]]],["Custom events enable waterfall mediation for unsupported ad networks by implementing a custom event adapter. This requires creating the event in the AdMob UI, providing a class name, label, and optional parameter. The adapter's `initialize()` method is called during SDK initialization to set up the third-party SDK. All custom events must report their adapter and the third-party SDK's version numbers using `VersionInfo`. Finally, specific instructions to request an ad are available per ad format.\n"],null,["Custom events let you add waterfall mediation for an ad network that isn't a\n[supported ad network](/admob/android/choose-networks). You do this by implementing\na custom event adapter for the ad network you want to integrate.\n\nYou can find a full sample custom event project in our [GitHub\nrepo](//github.com/googleads/googleads-mobile-android-mediation).\n\nPrerequisites\n\nBefore you can create custom events, you must first integrate one of the\nfollowing ad format into your app:\n\n- [Banner](/admob/android/banner)\n- [Interstitial](/admob/android/interstitial)\n- [Native](/admob/android/native)\n- [Rewarded](/admob/android/rewarded)\n\nCreate a custom event in the UI\n\nA custom event must first be created in the AdMob\nUI. See the instructions in\n\n[Add a custom event](//support.google.com/admob/answer/3083407).\n\n\nYou need to supply the following:\n\nClass Name\n\n: The fully-qualified name of the class that implements the custom event\n adapter---for example,\n\n `com.google.ads.mediation.sample.customevent.SampleCustomEvent`. As a best\n practice, we recommend using a single adapter class for all custom event ad\n formats.\n\nLabel\n\n: A unique name defining the ad source.\n\nParameter\n\n: An optional string argument passed to your custom event adapter.\n\nInitialize the adapter\n\nWhen the Google Mobile Ads SDK initializes,\n\n`initialize()`\n\nis invoked on all supported third-party adapters and custom events configured\nfor the app within the AdMob UI. Use this method to\nperform any necessary setup or initialization on the required third-party SDK\nfor your custom event. \n\nJava \n\n package com.google.ads.mediation.sample.customevent;\n\n import com.google.android.gms.ads.mediation.Adapter;\n import com.google.android.gms.ads.mediation.InitializationCompleteCallback;\n import com.google.android.gms.ads.mediation.MediationConfiguration;\n\n public class SampleAdNetworkCustomEvent extends Adapter {\n private static final String SAMPLE_AD_UNIT_KEY = \"parameter\";\n\n @Override\n public void initialize(Context context,\n InitializationCompleteCallback initializationCompleteCallback,\n List\u003cMediationConfiguration\u003e mediationConfigurations) {\n // This is where you will initialize the SDK that this custom\n // event is built for. Upon finishing the SDK initialization,\n // call the completion handler with success.\n initializationCompleteCallback.onInitializationSucceeded();\n }\n }\n\nKotlin \n\n package com.google.ads.mediation.sample.customevent\n\n import com.google.android.gms.ads.mediation.Adapter\n import com.google.android.gms.ads.mediation.InitializationCompleteCallback\n import com.google.android.gms.ads.mediation.MediationConfiguration\n\n class SampleCustomEvent : Adapter() {\n private val SAMPLE_AD_UNIT_KEY = \"parameter\"\n\n override fun initialize(\n context: Context,\n initializationCompleteCallback: InitializationCompleteCallback,\n mediationConfigurations: List\u003cMediationConfiguration\u003e\n ) {\n // This is where you will initialize the SDK that this custom\n // event is built for. Upon finishing the SDK initialization,\n // call the completion handler with success.\n initializationCompleteCallback.onInitializationSucceeded()\n }\n }\n\nReport version numbers\n\nAll custom events must report to the Google Mobile Ads SDK both the version of\nthe custom event adapter itself and the version of the third-party SDK the\ncustom event interfaces with. Versions are reported as\n\n[`VersionInfo`](/admob/android/reference/com/google/android/gms/ads/VersionInfo)\n\nobjects: \n\nJava \n\n package com.google.ads.mediation.sample.customevent;\n\n public class SampleCustomEvent extends Adapter {\n\n @Override\n public VersionInfo getVersionInfo() {\n String versionString = new VersionInfo(1, 2, 3);\n String[] splits = versionString.split(\"\\\\.\");\n\n if (splits.length \u003e= 4) {\n int major = Integer.parseInt(splits[0]);\n int minor = Integer.parseInt(splits[1]);\n int micro = Integer.parseInt(splits[2]) * 100 + Integer.parseInt(splits[3]);\n return new VersionInfo(major, minor, micro);\n }\n\n return new VersionInfo(0, 0, 0);\n }\n\n @Override\n public VersionInfo getSDKVersionInfo() {\n String versionString = SampleAdRequest.getSDKVersion();\n String[] splits = versionString.split(\"\\\\.\");\n\n if (splits.length \u003e= 3) {\n int major = Integer.parseInt(splits[0]);\n int minor = Integer.parseInt(splits[1]);\n int micro = Integer.parseInt(splits[2]);\n return new VersionInfo(major, minor, micro);\n }\n\n return new VersionInfo(0, 0, 0);\n }\n }\n\nKotlin \n\n package com.google.ads.mediation.sample.customevent\n\n class SampleCustomEvent : Adapter() {\n override fun getVersionInfo(): VersionInfo {\n val versionString = VersionInfo(1,2,3).toString()\n val splits: List\u003cString\u003e = versionString.split(\"\\\\.\")\n\n if (splits.count() \u003e= 4) {\n val major = splits[0].toInt()\n val minor = splits[1].toInt()\n val micro = (splits[2].toInt() * 100) + splits[3].toInt()\n return VersionInfo(major, minor, micro)\n }\n\n return VersionInfo(0, 0, 0)\n }\n\n override fun getSDKVersionInfo(): VersionInfo {\n val versionString = VersionInfo(1,2,3).toString()\n val splits: List\u003cString\u003e = versionString.split(\"\\\\.\")\n\n if (splits.count() \u003e= 3) {\n val major = splits[0].toInt()\n val minor = splits[1].toInt()\n val micro = splits[2].toInt()\n return VersionInfo(major, minor, micro)\n }\n\n return VersionInfo(0, 0, 0)\n }\n }\n\nRequest ad\n\nTo request an ad, refer to the instructions specific to the ad format:\n\n- [Banner](/admob/android/custom-events/banner)\n- [Interstitial](/admob/android/custom-events/interstitial)\n- [Native](/admob/android/custom-events/native)\n- [Rewarded](/admob/android/custom-events/rewarded)"]]