Course welcome video captions in your brand color (slam, $0.20)

To burn captions in your course's brand color, call POST /v1/video-captions with style: "slam" and design: { "colors": { "active": "#hex" } }. The active color is the one used to emphasise the spoken word, and every other token keeps the style's default. Standalone captions are $0.20 for a clip of up to 60 seconds.

Design overrides work on every named style except punch and tiktok-green, which the docs say still render on a path that reads none of the tokens. Source: Video captions, read 2026-10-04.

What you can change

A style is a set of design tokens, and each group merges over the style's own value, so one key changes one thing.

Request

Colors are hex, rgb()/rgba() or transparent. Any other CSS syntax is rejected, and a number outside its documented range is a 400 at request time, so a wrong value fails before it bills.

curl -X POST https://api.sume.com/v1/video-captions \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: course-welcome-captions-001" \
  -d '{
    "video_url": "https://example.com/welcome.mp4",
    "style": "slam",
    "language": "en",
    "design": { "colors": { "active": "#F59E0B" } }
  }'

Spell the course name correctly

Pass script_text if your welcome script is fixed. Sume keeps speech-to-text timings and aligns the burned wording to your script, so names such as the course title are spelled the way you wrote them. If alignment fails you get script_alignment_mismatch or script_alignment_failed, and the suggested next action is to simplify the script or omit it.

Restyle for a second brand

Once one welcome video is approved, restyle it without a second transcription by sending source_caption_id in place of video_url. Sume reuses the source video and the word timings it already has. Billing is unchanged, because a restyle is still a render.

If the clip came from Avatar Video, you can instead set inline captions on talking-video. Inline captions are not billed separately and are limited to videos of 60 seconds or less.

• One welcome video, two brand colors: two caption jobs, the second with source_caption_id.
• Silent clip: pass cues with text, start and end, because a silent clip with no cues fails as caption_no_speech.