Steps to integrate SMSRetrievalApi in android application:

build.gradle (app level) :

---

add this dependencies :

//for google auth and if you want to use hint number request implementation 'com.google.android.gms:play-services-auth:16.0.1'

//for SmsRetriever implementation 'com.google.android.gms:play-services-auth-api-phone:16.0.0'

manifest.xml

---

add a broadcast receiver with following intent filter :

for example :

    <receiver
            android:name=".receiver.MySMSBroadcastReceiver"
            android:exported="true">
        <intent-filter>
            <action android:name="com.google.android.gms.auth.api.phone.SMS_RETRIEVED" />
        </intent-filter>
    </receiver>

application module :

---

add code to get hash key from application create a broadcastReceiver to receiver otp code register broadcastReceiver with intent filter ex. val intentFilter = IntentFilter() intentFilter.addAction(SmsRetriever.SMS_RETRIEVED_ACTION) applicationContext.registerReceiver(mySMSBroadcastReceiver, intentFilter)

start SmsRetrieverListener by calling below method : ex. private fun startSMSListener() { val client = SmsRetriever.getClient(this) val task = client.startSmsRetriever() task.addOnSuccessListener {

        Toast.makeText(this, "SMS Retriever starts", Toast.LENGTH_LONG).show()
    }

    task.addOnFailureListener {
       
        Toast.makeText(this, "Error", Toast.LENGTH_LONG).show()
    }
}

register data callback from broadcastReceiver to get otp where you want..

AND******

if you want to use hintRequestIntent to get user number from phone then :

setup googleApiClient ex. mGoogleApiClient = GoogleApiClient.Builder(this) .addConnectionCallbacks(this) .enableAutoManage(this, this) .addApi(Auth.CREDENTIALS_API) .build()

request for numberHint by calling this method : ex. private fun getHintPhoneNumber(){ val hintRequest = HintRequest.Builder() .setPhoneNumberIdentifierSupported(true) .build() val intent = Auth.CredentialsApi.getHintPickerIntent( mGoogleApiClient, hintRequest ) startIntentSenderForResult(intent.intentSender, RESOLVE_HINT, null, 0, 0, 0) }

get selected number in onActivityResult like :

 if (requestCode == RESOLVE_HINT) {
        if (resultCode == Activity.RESULT_OK) {

            var credential: Credential = data!!.getParcelableExtra(Credential.EXTRA_KEY)
            // credential.getId();  <-- will need to process phone number string
        }
    }

:::::: process with number now

working ... :-)