Video captions rejects a signed URL: what to send instead

A signed or presigned storage link is the usual way to share a private video file, and Sume video captions refuses it. The docs, read 2026-10-05, say video_url must be a public HTTPS video URL that Sume can fetch, and the API rejects localhost, private-network, non-HTTPS, signed or private, and provider task URLs. The same screening applies to other URL inputs, such as face-swap sources.

In practice, a signed link expires and can carry credentials in its query string. The docs do not give Sume's reason, but a job that runs after you submit could find an expired link, so a stable public or artifact URL is safer.

What to send instead

• A public HTTPS URL to the file, hosted where anyone can fetch it for the length of the job.
• A media.sume.com artifact URL from an earlier Sume job, such as a finished generation or trim. The docs examples use this form.
• A restyle of an earlier caption job: send source_caption_id and no video_url, and Sume reuses that source video.

Request with an artifact URL

curl -X POST https://api.sume.com/v1/video-captions \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: caption-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/example/clean.mp4",
    "style": "punch"
  }'

Cost and limits

Each accepted standalone caption job reserves and captures $0.20 for a video up to 60 seconds. If the clip has no speech, the job fails with caption_no_speech, and the way through is to send authored cues instead. The API does not accept SRT uploads.