Continuing the legacy of Vanced

Expose like status in MediaSession

A ReVanced patch for YouTube that publishes the current video's id and like status into the media session metadata, so another application can read them over a MediaController.

It was written for a car head unit launcher whose favourite button needs to know whether the playing video is liked. YouTube does not expose that: unlike Spotify or Apple Music, it publishes no Rating and no like/dislike custom actions, so any external media client is blind to it.

What it adds

Three values are written into MediaMetadata alongside YouTube's own:

Key	Type	Meaning
android.media.metadata.MEDIA_ID	String	the 11 character video id
com.android.launcher66.LIKE_EVENT_SEQ	long	counter, bumped every time a status is published
com.android.launcher66.LIKE_STATUS	long	-1 cleared, 0 none, 1 like, 2 dislike

The video id is the important one. With it a receiving application can ask the YouTube Data API (videos.getRating) for the authoritative status, which is the only reliable source for a video that was already liked before playback started.

The sequence counter exists so a receiver can tell a real event from a stale value. It is bumped on every published status, including the reset that happens when the track changes — so a receiver that restarts mid-video cannot mistake an old value for a fresh one. Ratings sent to YouTube over the media session never bump it, which lets a receiver ignore the echo of its own actions.

How it works

Two injection points:

MediaSession.setMetadata — the metadata is routed through the extension on its way to the session, which adds the three keys. The target is a framework class, so this hook is immune to obfuscation and survives YouTube updates.

The like event constructor — invoked whenever the user taps the thumb inside YouTube. This one targets an obfuscated class name and will break on updates; see PATCH_MAINTENANCE.md for how to find the new one. Losing it costs only the immediate reaction to in-app taps; everything else keeps working.

The video id is obtained by calling ReVanced's own VideoInformation.getVideoId() reflectively. That extension lives in the same APK and its names are kept by the project's proguard rules, which avoids having to locate the id in obfuscated code.

Known limitations

Videos made for kids report no rating. videos.getRating answers none for them however they were rated, and they never appear in myRating=like. This is a limitation on Google's side and cannot be worked around.

Ratings sent over the media session do not reach the account. YouTube applies them to its own interface only — they show up in the app and even in a browser, but the Data API does not see them and they are absent from the liked videos list. An application that wants a rating to stick must write it through videos.rate instead, and may then send the session rating afterwards purely to refresh the on-screen thumb.

The status of a video liked before playback started is not available here. YouTube does not surface it through any Java object at load time; it goes straight to the native renderer as a protobuf buffer. Six independent attempts to intercept it failed, which is why the video id is published instead and the question is left to the Data API.

Building

Requires JDK 17 or newer and the Android SDK. The patch is built with the ReVanced patches Gradle plugin:

./gradlew build

Then applied together with the official bundle, so GmsCore support and the rest are kept:

java -jar revanced-cli.jar patch \
  -p patches.rvp -b \
  -p patches/build/libs/patches-1.0.4.rvp -b \
  --keystore=my.keystore --purge \
  -o youtube-patched.apk stock.apk

Last verified against YouTube 20.40.45.

Consuming the metadata

MediaMetadata metadata = controller.getMetadata();
String videoId = metadata.getString(MediaMetadata.METADATA_KEY_MEDIA_ID);
long seq = metadata.getLong("com.android.launcher66.LIKE_EVENT_SEQ");
long status = metadata.getLong("com.android.launcher66.LIKE_STATUS");

Treat a change of seq as the event and the accompanying status as its value. Reading status on its own is not safe: it is stale after the receiver sends a rating of its own, because that takes a different path inside YouTube and never reaches the patch.

PATCH_MAINTENANCE