Twitch clip captions: edit text and timing, burn them in

Twitch's own caption editor works inside Twitch. If you have a clip as a video file and want the words, timing and look under your control, burn them with POST /v1/video-captions: pass cues with text, start and end and Sume draws exactly that copy, with no speech-to-text.

Twitch details are from its TwitchCon Rotterdam post, and Sume details from Video captions, read 2026-09-30.

What is Twitch adding for clip captions?

The post says Auto Clips generates captioned clips from the best moments of a stream. It also says Twitch is rolling out the ability to add captions to community clips automatically, with editable text, timing and style so they work for viewers watching with sound off.

What can Sume do with a clip file?

How do I get an editable transcript first?

Import the clip, then call POST /v1/video-inspect with transcribe: true and sentence segmentation to get lines with start and end. Fix the text in your own editor and send the result as cues. script_text, words, cues and segments are mutually exclusive, so send one. A silent clip fails speech-to-captions, and cues is the documented way around that.

Should I trim the highlight first?

If the moment you want sits inside a longer recording, cut it with POST /v1/video-trim using start plus end or duration (exactly one of the two), then caption the new file. Cue times are in seconds from the start of the video you caption, so caption after trimming. See burn captions onto a video for the request shape.