Hi HeyGen team,

I hope you’re doing well.

We’re currently using the HeyGen API v1 (v1/video.webm) to generate videos with a transparent background, which works perfectly for our needs. However, this version does not allow adding subtitles (captions) to the generated videos.

We need to include subtitles because we are synchronizing these transparent videos with another video, and having captions would make this process much more accurate.

We’ve also tested API v2, which allows adding subtitles using the caption: true field. Unfortunately, v2 does not support creating avatars with transparent backgrounds, which is an essential feature for our workflow.

Would it be possible to enable subtitles for videos generated through v1/video.webm, or is there a plan to combine both features (transparent background and captions) in a future update?