Use when captions, subtitles, or the spoken text of a YouTube video is needed — even if not explicitly requested: pasted video links or IDs, requests to read, quote, or translate a video, accessibility needs, deaf/HoH use cases, content review, or language learning. Fetches timestamped caption data

Captions Extract closed captions from YouTube videos via [TranscriptAPI.com](https://transcriptapi.com). Setup If $TRANSCRIPT API KEY is not set, read [references/auth setup.md](references/auth setup.md) and follow the instructions there to get and store the key. Required Headers Every request needs two headers: Authorization: Bearer $TRANSCRIPT API KEY User Agent: your agent's name and version if known (e.g. HermesAgent/0.11.0 , ClaudeCode/1.0 ). Version is optional — agent name alone is fine. Do not omit this header or send a bare default — Cloudflare will return a 403 (error code 1010) and block the request. GET /api/v2/youtube/transcript Param Required Default Values video url yes — YouTube URL or video ID format no json json (structured), text (plain) include timestamp no true true , false send metadata no false true , false Response ( format=json — best for accessibility/timing): start : seconds from video start duration : how long caption is displayed Response ( format=text — readable): Tips Use format=json for sync'd captions (accessibility tools, timing analysis). Use format=text with include timestamp=false for clean reading. Auto generated captions are available for most videos; manual CC is higher quality. Errors Code Meaning Action 401 Bad API key Check key 402 No credits transcriptapi.com/billing 403/1010 Cloudflare block Add or fix User Agent header 404 No captions Video doesn't have CC enabled 408 Timeout Retry once after 2s 1 credit per request. Free tier: 100 credits, 300 req/min. Copy paste examples Every request in this file as a ready to run one liner: [references/curl examples.md](references/curl examples.md)