Captions

Extract closed captions from YouTube videos via TranscriptOut.com.

Setup

If $TRANSCRIPTOUT_API_KEY is not set, read references/auth-setup.md and follow the instructions there to get and store the key.

Required Header

Every request needs one header:

• Authorization: Bearer $TRANSCRIPTOUT_API_KEY

Every response is one JSON envelope. Success: {"ok": true, "request_id": "...", "data": {...}}. Error: {"ok": false, "code": "...", "detail": "...", "request_id": "..."}. Branch on the machine-readable code, not on the human text. The remaining credit balance rides in the X-Credits-Remaining response header.

GET /v1/transcript · 1 credit

Fetch the closed captions of any YouTube video: timed JSON segments, plain text, or ready-made SRT/VTT files.

# SRT body inside the JSON envelope
curl -s "https://api.transcriptout.com/v1/transcript?video=VIDEO_URL_OR_ID&format=srt" \
  -H "Authorization: Bearer $TRANSCRIPTOUT_API_KEY"

# or the raw .srt file itself
curl -s "https://api.transcriptout.com/v1/transcript?video=VIDEO_URL_OR_ID&format=srt&download=true" \
  -H "Authorization: Bearer $TRANSCRIPTOUT_API_KEY"

Param	Required	Default	Values
video	yes	-	YouTube URL (full/short/shorts) or 11-char video ID
lang	no	en	language code of the track (en, de, ...)
format	no	json	json, text, srt, vtt, srv3
kind	no	manual if present	manual, auto
segment	no	auto tracks: 180 (80 for srt/vtt). Manual tracks keep the author's lines	20-5000, max characters per segment
video_metadata	no	false	true adds data.metadata (title, channel, duration, views) for the same 1 credit
download	no	false	true returns the raw file instead of the JSON envelope (text/srt/vtt/srv3 only)

With format=srt or format=vtt the default segmenting for auto-generated tracks is subtitle-sized (~80 characters per cue). Manual tracks keep the author's own line breaks in every format. download=true returns the bare file instead of the JSON envelope.

Response for format=json. With format=text/srt/vtt/srv3 the transcript field is one string in that format:

{
  "ok": true,
  "request_id": "req_...",
  "data": {
    "video_id": "dQw4w9WgXcQ",
    "language": "en",
    "kind": "manual",
    "transcript": [
      { "text": "Never gonna give you up", "start": 18.0, "duration": 4.12 },
      { "text": "Never gonna let you down", "start": 22.12, "duration": 3.85 }
    ],
    "available_langs": [
      { "code": "en", "kind": "manual", "name": "English" },
      { "code": "en", "kind": "auto", "name": "English (auto-generated)" }
    ]
  }
}

Tips

• format=text is the cheapest form to reason over. Ask for json only when timestamps matter.
• Transcript AND title/channel wanted? One call: video_metadata=true. Never a separate /v1/video first.
• Transcribe last: search and listings are for choosing, and pulling transcripts for a whole results page nobody asked to read is the fastest way to burn a balance.

Errors

Code	Meaning	Action
400/422	Bad parameter	Fix the request. Credit refunded automatically
401	Bad or missing API key	Check the key. It must start with sk_
402	Out of credits	transcriptout.com/billing
404	No captions on that language/track, or bad ID	Definitive answer, do not retry. Try another lang or kind=auto. Billed
410	Video removed	Do not retry
451	Age-restricted or members-only	Do not retry
429	Rate limit (200 req/min per key)	Wait, respect Retry-After. Refunded
502	Failed on YouTube's side	One retry is reasonable. Billed
503	Service at capacity	Retry after Retry-After. Refunded

Every error body carries a machine-readable code and a request_id. Include the request_id when contacting support.