Subtitles

Fetch YouTube video subtitles via TranscriptAPI.com.

Setup

If $TRANSCRIPT_API_KEY is not set, read 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

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

Param	Values	Use case
video_url	YouTube URL or video ID	Required
format	json, text	json for sync'd subs with timing
include_timestamp	true, false	false for clean text for reading/translation
send_metadata	true, false	Include title, channel, description

For language learning — clean text without timestamps:

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

For translation — structured segments:

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

Response (format=json):

{
  "video_id": "dQw4w9WgXcQ",
  "language": "en",
  "transcript": [
    { "text": "We're no strangers to love", "start": 18.0, "duration": 3.5 }
  ]
}

Response (format=text, include_timestamp=false):

{
  "video_id": "dQw4w9WgXcQ",
  "language": "en",
  "transcript": "We're no strangers to love\nYou know the rules and so do I..."
}

Tips

• Many videos have auto-generated subtitles in multiple languages.
• Use format=json to get timing for each line (great for sync'd reading).
• Use include_timestamp=false for clean text suitable for translation apps.

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 subtitles	No subtitles available
408	Timeout	Retry once after 2s

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