RCS, which stands for Rich Communication Services, is generally seen as the successor to SMS. It supports features like group chat management, higher quality file sharing, read receipts, write indicators and end-to-end encryption. In order to use the RCS protocol for chats, it must be supported by the network, the phone’s OS and the phone’s messaging app via an API. US carriers dragged their feet too long by adopting RCS, so Google bypassed them completely and added their own RCS backend to the Google Messages app. But on Android, only The Google Messages app has access to Android’s RCS API. That may change if Google opens its “Android Messages API.”
Back in 2019, we learned that Google was working on adding an RCS API. Unfortunately, the APIs were hidden from developers and can only be used by apps on a hidden permission list ̵
As Google Messages rolled out today on Google Play, we decoded the APK and discovered the following strings in its resources:
With this permission the app will be allowed to send SMS/MMS/RCS using Android Messages. It will have an access to send messages without any extra approvals. Permission to send SMS/MMS/RCS messages using Android Messages API
These strings clearly describe a permission that third-party messaging apps may request to send SMS, MMS, or RCS messages through the Google Messages app. Within the Google Messages app Manifest file, we also found the permission that messaging apps must declare:
The permission type is specified as “dangerous”, which means that it is not granted to a requesting app without a confirmation displayed to the user. This is also suggested in the strings embedded above, which say that an app that has the permission can “send messages without anyone additional approvals ”, which means that the approval must first be given. The permission is grouped under the SMS category, which makes sense as it is only meant to be used by messaging apps.
While we were hoping to see Google open the Android platform’s RCS API, there’s potentially a huge benefit to having Google Messages to handle messaging route. This may mean that all RCS messages sent via a third-party messaging app will use Google’s chat service, which is by far the most widely used RCS implementation, as none of the carriers’ versions have been launched.
We have not found a message from Google on this Android Messages API yet, but we hope to see it open soon. Third-party SMS apps are at a disadvantage right now as they lack RCS support, but this API means you can use your favorite SMS app and enjoy the benefits of RCS. Of course, the third-party SMS app should actually implement the new API, but it does not look like it will be too difficult to implement.
Shortly after we published this article, we learned that the strings and manifest mail for the Android Messages API can only be found in the Google Messages app for Samsung Galaxy phones. It’s the same app and package name, but Google Play is dynamically rolling out this version of the app to Samsung Galaxy phones. These entries were added several versions ago, so the API itself does not appear to be new. We’m not sure why the entries only appear in the version of the app for Samsung phones, but it’s possible that Google created the API so that Samsung’s Messaging app can use Google’s chat service without users having to switch apps . However, we do not see why this API cannot be opened for other apps, nor can we see any evidence yet in the Samsung Messages app itself that it uses this API. Hopefully, Google will open the API for all third-party messaging apps by including it in the main version of the app.
This article was last updated on 14:52 ET to reflect that the Android Messages API seems to have been added several versions since to the Google Messages app for Samsung Galaxy phones. The title of this post was updated to reflect this new information.