📝 Captions & Media
Caption tracks, thumbnails, watermarks, and playlist cover images — all local-file uploads.
Eleven tools cover media assets uploaded from a local file path: caption tracks, video thumbnails, channel watermarks, and playlist cover images.
| Tool | Quota cost | Notes |
|---|---|---|
list-captions | 50 units | Caption tracks for a video |
upload-caption | 400 units | Local file (SRT/VTT/SBV/TTML) |
update-caption | 450 units | Draft status, optional re-upload |
download-caption | 200 units | Writes to a local file path |
delete-caption | 50 units | Requires confirm: true |
set-thumbnail | 50 units | Local image file |
set-watermark | 50 units | Local image file |
unset-watermark | 50 units | Requires confirm: true |
list-playlist-images | 1 unit | Cover images for a playlist |
upload-playlist-image | 50 units | Local image file |
update-playlist-image | 50 units | Replace an existing cover's file |
delete-playlist-image | 50 units | Requires confirm: true |
Captions
list-captions reads the caption tracks on a video. upload-caption uploads a new track from a local file — pass language (BCP-47, e.g. en) and a display name. update-caption changes a track's draft status and can optionally re-upload its content from a local filePath. download-caption writes a track to a local outputPath, optionally converting format (e.g. srt, vtt, ttml) or translating to another language. delete-caption permanently removes a track and requires confirm: true.
Thumbnails and watermarks
set-thumbnail uploads and sets a video's custom thumbnail from a local image. set-watermark uploads and sets a channel's video watermark, positioned in a screen corner (topLeft/topRight/bottomLeft/bottomRight) with offsetMs/durationMs timing controls. unset-watermark removes it and requires confirm: true.
Playlist images
Playlist cover images are a newer resource for playlist artwork. list-playlist-images reads the images attached to a playlist (parent). upload-playlist-image and update-playlist-image upload from a local file. delete-playlist-image permanently removes one and requires confirm: true.
MIME type detection
All upload tools infer the MIME type from the file extension (.mp4, .mov, .webm, .png, .jpg, .srt, .vtt, and others) — there's no separate mimeType parameter to set.