The document discusses SMS verification APIs that allow apps to automatically retrieve verification codes from SMS messages without requesting full SMS permissions. It describes the SMS Retriever API which allows apps to listen for SMS messages in the background and retrieve the code without user interaction. It also covers the SMS User Consent API which prompts the user to allow the app to access their SMS messages one time during setup for verification. The prerequisites and code snippets provided show how to integrate these APIs, including starting the SMS listener, handling the broadcast receiver, and retrieving the code or consent intent.

1. SMS Verification APIs

2. SMS verification APIs
“Verify your users by SMS without making them deal with
verification codes. By using the SMS Retriever API, your app
can automatically retrieve verification codes intended for
your app, without having to request full SMS reading
permissions.”
• SMS permission is dangerous
https://developers.google.com/identity/sms-retriever/

3. • One tap verification
• Automatic verification

4. SMS User Consent -
One-tap SMS verification

5. Prerequisite - dependencies
implementation 'com.google.android.gms:play-services-auth:17.0.0'
implementation 'com.google.android.gms:play-services-auth-api-phone:
17.1.0'

6. Start listen user’s SMS
SmsRetriever.getClient(this).startSmsUserConsent(null)

7. Request consent
(1/2)
class MySMSBroadcastReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
if (SmsRetriever.SMS_RETRIEVED_ACTION == intent.action) {
val extras = intent.extras
val status = extras!!.get(SmsRetriever.EXTRA_STATUS) as Status
when (status!!.statusCode) {
CommonStatusCodes.SUCCESS -> {
val consentIntent = extras.getParcelable<Intent>(
SmsRetriever.EXTRA_CONSENT_INTENT)
startActivityForResult(consentIntent, SMS_CONSENT_REQUEST)
}
…
}
}

8. Request consent
(2/2)
<receiver android:name=".MySMSBroadcastReceiver" android:exported="true">
<intent-filter>
<action
android:name="com.google.android.gms.auth.api.phone.SMS_RETRIEVED"/>
</intent-filter>
</receiver>

9. Hande SMS
(if user is OK about it)
override fun onActivityResult(requestCode: Int, resultCode: Int, data:
Intent?) {
…
if (requestCode == SMS_CONSENT_REQUEST) {
// full text of message
data.getStringExtra(SmsRetriever.EXTRA_SMS_MESSAGE)
}
}

10. SMS Retriver -
Automatic SMS verification

11. Prerequisite - dependencies
implementation 'com.google.android.gms:play-services-auth:16.0.1'
implementation 'com.google.android.gms:play-services-auth-api-phone:
16.0.0'

12. Start listen user’s SMS
SmsRetriever.getClient(this).startSmsRetriever()

13. Retrive SMS
(1/2)
class MySMSBroadcastReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
if (SmsRetriever.SMS_RETRIEVED_ACTION == intent.action) {
val extras = intent.extras
val status = extras!!.get(SmsRetriever.EXTRA_STATUS) as Status
when (status!!.statusCode) {
CommonStatusCodes.SUCCESS -> {
val message = extras.get(
SmsRetriever.EXTRA_SMS_MESSAGE) as String // full text of SMS
}
…
}
}

14. Retrive SMS
(2/2)
<receiver android:name=".MySMSBroadcastReceiver" android:exported="true">
<intent-filter>
<action
android:name="com.google.android.gms.auth.api.phone.SMS_RETRIEVED"/>
</intent-filter>
</receiver>

15. <#>
Your ExampleApp code is: 123ABC78
FA+9qCX9VSu
SMS Retriver SMS format:

16. Broadcast receiver(s)
class MySMSBroadcastReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
if (SmsRetriever.SMS_RETRIEVED_ACTION == intent.action) {
val extras = intent.extras
val message = extras.get(SmsRetriever.EXTRA_SMS_MESSAGE) as String
}
}
class MySMSBroadcastReceiver : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
if (SmsRetriever.SMS_RETRIEVED_ACTION == intent.action) {
val extras = intent.extras
val consentIntent = extras.getParcelable<Intent>(
SmsRetriever.EXTRA_CONSENT_INTENT)
startActivityForResult(consentIntent, SMS_CONSENT_REQUEST)
}
Request user consent if app use SMS consent API
Retrieve SMS immediately if app use SMS retriever API