Reply to a YouTube comment with a Short: the comment sticker

You reply to a comment with a Short from inside the YouTube app: tap Reply on the comment, then the Shorts icon next to it, and the Shorts creator opens with that comment drawn as a sticker. The commenter is told, and the Short shows up in the comment feed under the original comment, just like a text reply, according to YouTube's help page.

The sticker itself is made by YouTube. A video file made elsewhere cannot carry it as a live element. What Sume can do is make the answer clip, so that when you open the Shorts creator you import a clip that is ready.

How do I start a reply Short?

YouTube lists two entry points in the mobile app, plus a saved-comment route. All three end in the same Shorts creation screen. Once you are in it, you can drag to reposition the comment sticker or pinch to resize it, and use the other Shorts tools.

Can I tell which video a comment is on?

Yes. In the Comments panel, tap More and then See video details on a comment to learn which video it was posted on. This matters if you reply from the camera rather than from the watch page, because the panel lists comments from across your channel.

You can also unsave a comment: when viewing saved comments in Shorts, tap More and Unsave on the comment.

What does Sume add to a reply?

A reply Short needs a clip. You can record it on the phone, or make it elsewhere and bring it in through the gallery button in the Shorts camera. For the second route, Sume gives three building blocks, each from its docs:

• Generated clip: the Video Router takes a prompt with aspect_ratio 9:16; its Auto create controls default to 720p and 8 seconds, with 3 to 10 second clips at 16:9 or 9:16.
• Talking presenter: an avatar video turns a script into a talking video; scripts must estimate at 4 to 60 seconds, and aspect_ratio defaults to 9:16.
• Cut an existing answer: video trim cuts [start, end) out of one clip for $0.02 per job, with duration from 0.2 to 900 seconds.

A trim request for a longer answer

Say you recorded a two-minute answer and want the first 45 seconds as the reply. Import it first, because trim reads only your workspace's media.sume.com files; the media inputs page shows how. Then send:

curl -X POST https://api.sume.com/v1/video-trim \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: reply-cut-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/answer.mp4",
    "start": 0,
    "duration": 45
  }'

What to keep in mind when you import it

The comment sticker sits on top of your video, so leave room at the top of the frame, and test with the sticker dragged around. Because the sticker is YouTube's, the reply needs no on-screen quote; a typed question in the picture would repeat it.

Use a short reply, since a Short reply is shown with the original comment and the commenter is notified. Check the final upload on your phone: the sticker, your clip and any text you burned in all share the same small screen.

One more habit helps: keep a master file of every reply. If you later want the answer as a standalone Short, you can re-cut it from the master, and the clip you imported into the YouTube app does not have to be the only copy. Sume keeps the trimmed MP4 as a durable artifact in your workspace, so a second cut is one more trim call, not a re-render of the whole answer.