Captions

Captions

Extract closed captions from YouTube videos via TranscriptAPI.com.

Setup

If $TRANSCRIPT_API_KEY is not set, read references/auth-setup.md [blocked] 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

curl -s "https://transcriptapi.com/api/v2/youtube/transcript\?video_url=VIDEO_URL&format=json&include_timestamp=true&send_metadata=true" \  -H "Authorization: Bearer $TRANSCRIPT_API_KEY" \  -H "User-Agent: YourAgent/1.0"

Response (format=json — best for accessibility/timing):

{  "video_id": "dQw4w9WgXcQ",  "language": "en",  "transcript": [    { "text": "We're no strangers to love", "start": 18.0, "duration": 3.5 },    { "text": "You know the rules and so do I", "start": 21.5, "duration": 2.8 }  ],  "metadata": { "title": "...", "author_name": "...", "thumbnail_url": "..." }}

• start: seconds from video start
• duration: how long caption is displayed

Response (format=text — readable):

{  "video_id": "dQw4w9WgXcQ",  "language": "en",  "transcript": "[00:00:18] We're no strangers to love\n[00:00:21] You know the rules..."}

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

1 credit per request. Free tier: 100 credits, 300 req/min.