We can debate all day about the quality of the hardware on Pixel smartphones, but I'm sure that most of us can agree that the software is where Pixel devices really shine. Each new Pixel device introduced new software features that are widely sought after in the community, and for the Pixel 3, one of those new features was Call Screen. This feature is available for all Pixel devices and even some Motorola phones as well, and it helps shield you from robocallers by answering calls with a series of questions to figure out why you're being called. Describing Call Screen makes it seem incredibly "smart," but in reality, initiating it and selecting responses are all user-controlled. That could change in an upcoming update, however, as we spotted strings for a new automatic Call Screen feature.

An APK teardown can often predict features that may arrive in a future update of an application, but it is possible that any of the features we mention here may not make it in a future release. This is because these features are currently unimplemented in the live build and may be pulled at any time by the developers in a future build.

Google Phone v42 rolled out earlier this morning on the Google Play Store, and an APK for the update is available on APKMirror. We downloaded the APK and decoded the resources to look for new strings. In the latest update, we found a large number of strings relating to a feature code-named "revelio." We've been tracking the development of this feature since early August when code for it was first added, but at the time, it was ambiguous whether it was a new Call Screen feature or spam detection feature. The strings now make this clear. The code-name "revelio" likely refers to the Harry Potter spell that removes magical disguises.

Automatic Call Screening

These first strings describe the settings toggles for automatic call screening. You'll be able to either automatically screen to decline robocalls, ring the phone (which is the default behavior), or automatically silently decline the call.

        <string name="call_action_label_automatically_screen">Automatically screen. Decline robocalls.</string>
<string name="call_action_label_ring_phone">Ring phone (default)</string>
<string name="call_action_label_silently_decline">Silently decline</string>

This next batch of strings describes how the automatic Call Screen feature works. The demo page says that the Google Assistant automatically answers unknown calls on your behalf; detected robocalls are silently declined without ever interrupting you, while unknown numbers ring a few moments later and a transcript is saved of the call. Any number saved in your contact list is never screened so you'll always receive them. If the Assistant was unable to automatically screen the call, you can tap a button in the notification to initiate manual Call Screen (ie. the current functionality.)

When the Assistant automatically answers calls for you, you have the option to save the audio from those short calls. We spotted evidence for this back in early August, but at the time it wasn't clear if the feature would be available for manual Call Screens due to potential legal issues with users recording calls in some US States. Now it's clear that this feature is intended for automatic call screening, which makes sense as the Google Assistant will always announce to the other party that it will be recording calls.

Saving Call Screen Audio for Automatically Screened Calls

Here are more strings relating to saving the audio from screen calls. Previously, you could only save the transcript in Call Screen.

        <string name="conversation_history_dropdown_menu_full_transcript_link_text_with_audio">Transcript and audio</string>
<string name="conversation_history_dropdown_menu_full_transcript_link_text_without_audio">Transcript</string>
<string name="save_audio_error_cant_load_value">Unable to fetch current Save Call Screen audio value</string>
<string name="save_audio_error_cant_set_value">Unable to save Save Call Screen audio value</string>
<string name="low_confidence_revelio_summary_prefix">"(Audio wasn't clear) "</string>

Spam Preferences

Finally, these strings define spam preferences for the new feature. Spam detection on the Google Phone app will detect altered numbers, private or hidden numbers, unknown numbers, and/or numbers that match Google's spam database. These preferences will let you tweak what kinds of numbers the automatic Call Screen feature works on.

        <string name="possibly_faked_numbers_action_preference_description">Callers that may be spammers using an altered number</string>
<string name="possibly_faked_numbers_action_preference_key">possibly_faked_numbers_action_preference_key</string>
<string name="possibly_faked_numbers_action_preference_title">Possibly faked numbers</string>
<string name="private_or_hidden_action_preference_description">Callers hiding their caller ID</string>
<string name="private_or_hidden_action_preference_key">private_or_hidden_action_preference_key</string>
<string name="private_or_hidden_action_preference_title">Private or hidden</string>
<string name="unknown_call_settings_category_key">unknown_call_settings_category_key</string>
<string name="unknown_call_settings_category_preference_title">Unknown Call Settings</string>
<string name="spam_action_preference_description">"Numbers that match Google's spam database"</string>
<string name="spam_action_preference_key">spam_action_preference_key</string>
<string name="spam_action_preference_title">Spam</string>
<string name="screening_unknown_caller">Screening an unknown call</string>

This automatic Call Screen feature is not yet live on a Pixel 2 XL or Pixel 4 running the latest Google Phone 42 beta app. We don't know when Google will announce it, either. Jane Manchun Wong first activated the feature earlier today, but we also accessed the settings to bring you the following screenshots:

You can download Google Phone v42 from the Google Play Store link below.

Phone by Google Developer: Google LLC
Price: Free
4.4
Download

Thanks to PNF Software for providing us a license to use JEB Decompiler, a professional-grade reverse engineering tool for Android applications.

Update 1 (11/19/19 @ 11:15 AM ET): Added @wongmjane's tweet and reworded the spam preferences section.

Update 2 (11/19/19 @ 11:40 AM ET): Added our own screenshots of the feature.