YouTube is or could be relevant

TranscriptAPI

Full YouTube data toolkit via TranscriptAPI.com. Transcripts, search, channels, playlists — one API key.

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.

API Reference

Full OpenAPI spec: transcriptapi.com/openapi.json — consult this for the latest parameters and schemas.

Auth

All requests: -H "Authorization: Bearer $TRANSCRIPT_API_KEY"

Endpoints

Channel endpoints accept channel — an @handle, channel URL, or UC... ID. No need to resolve first. Playlist endpoints accept playlist — a playlist URL or ID.

GET /api/v2/youtube/transcript — 1 credit

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

Param	Required	Default	Validation
video_url	yes	—	YouTube URL or 11-char video ID
format	no	json	json or text
include_timestamp	no	true	true or false
send_metadata	no	false	true or false

Accepts: https://youtube.com/watch?v=ID, https://youtu.be/ID, youtube.com/shorts/ID, or bare ID.

Response (format=json):

{
  "video_id": "dQw4w9WgXcQ",
  "language": "en",
  "transcript": [
    { "text": "We're no strangers...", "start": 18.0, "duration": 3.5 }
  ],
  "metadata": { "title": "...", "author_name": "...", "author_url": "..." }
}

GET /api/v2/youtube/search — 1 credit

GET https://transcriptapi.com/api/v2/youtube/search?q=QUERY&type=video&limit=20
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Default	Validation
q	yes	—	1-200 chars (trimmed)
type	no	video	video or channel
limit	no	20	1-50

Response (type=video):

{
  "results": [
    {
      "type": "video",
      "videoId": "dQw4w9WgXcQ",
      "title": "Rick Astley - Never Gonna Give You Up",
      "channelId": "UCuAXFkgsw1L7xaCfnd5JJOw",
      "channelTitle": "Rick Astley",
      "channelHandle": "@RickAstley",
      "channelVerified": true,
      "lengthText": "3:33",
      "viewCountText": "1.5B views",
      "publishedTimeText": "14 years ago",
      "hasCaptions": true,
      "thumbnails": [{ "url": "...", "width": 120, "height": 90 }]
    }
  ],
  "result_count": 20
}

Response (type=channel):

{
  "results": [
    {
      "type": "channel",
      "channelId": "UCuAXFkgsw1L7xaCfnd5JJOw",
      "title": "Rick Astley",
      "handle": "@RickAstley",
      "subscriberCount": "4.2M subscribers",
      "verified": true,
      "rssUrl": "https://www.youtube.com/feeds/videos.xml?channel_id=UC..."
    }
  ],
  "result_count": 5
}

GET /api/v2/youtube/channel/resolve — FREE (0 credits)

GET https://transcriptapi.com/api/v2/youtube/channel/resolve?input=@TED
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Validation
input	yes	1-200 chars — @handle, URL, or UC... ID

Response:

{ "channel_id": "UCsT0YIqwnpJCM-mx7-gSA4Q", "resolved_from": "@TED" }

If input is already a valid UC[a-zA-Z0-9_-]{22} ID, returns immediately without lookup.

GET /api/v2/youtube/channel/videos — 1 credit/page

# First page (100 videos)
GET https://transcriptapi.com/api/v2/youtube/channel/videos?channel=@NASA
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

# Most-viewed first (channel Videos tab, ~30 videos)
GET https://transcriptapi.com/api/v2/youtube/channel/videos?channel=@NASA&sort=popular
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

# Next pages (repeat the same sort)
GET https://transcriptapi.com/api/v2/youtube/channel/videos?continuation=TOKEN&sort=popular
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Validation
channel	conditional	@handle, channel URL, or UC... ID
tab	no	videos (default), shorts, or streams
sort	no	latest, popular, or oldest (omit for the uploads feed)
continuation	conditional	non-empty string (next pages)

Provide exactly one of channel or continuation.

Sorting. Add sort=latest, popular, or oldest to channel/videos to get a channel's videos in the order you want, for example its most-popular uploads first. A sorted page returns about 30 videos (an unsorted page returns about 100), and every page costs the same 1 credit.

When paging, send the same sort on each request.

Every item carries members_only, true only when YouTube badges it "Members only", and those items have no viewCountText. Items from tab=streams carry lengthText and publishedTimeText (for example Streamed 2 years ago); tab=shorts returns null for both, because YouTube's Shorts grid publishes neither. On the channel-tab feeds (tab=videos with sort, tab=shorts, tab=streams) channelId, channelTitle, channelHandle and index are null.

Response:

{
  "results": [{
    "videoId": "abc123xyz00",
    "title": "Latest Video",
    "channelId": "UCsT0YIqwnpJCM-mx7-gSA4Q",
    "channelTitle": "TED",
    "channelHandle": "@TED",
    "lengthText": "15:22",
    "viewCountText": "3.2M views",
    "publishedTimeText": "2 years ago",
    "thumbnails": [...],
    "index": "0",
    "members_only": false
  }],
  "playlist_info": {"title": "Uploads from TED", "numVideos": "5000"},
  "continuation_token": "4qmFsgKlARIYVVV1...",
  "has_more": true
}

GET /api/v2/youtube/channel/latest — FREE (0 credits)

GET https://transcriptapi.com/api/v2/youtube/channel/latest?channel=@TED
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Validation
channel	yes	@handle, channel URL, or UC... ID

Returns last 15 videos via RSS with exact view counts and ISO timestamps.

Response:

{
  "channel": {
    "channelId": "...",
    "title": "TED",
    "author": "TED",
    "url": "..."
  },
  "results": [
    {
      "videoId": "abc123xyz00",
      "title": "Latest Video",
      "published": "2026-01-30T16:00:00Z",
      "viewCount": "2287630",
      "description": "Full description...",
      "thumbnail": { "url": "...", "width": "480", "height": "360" }
    }
  ],
  "result_count": 15
}

GET /api/v2/youtube/channel/search — 1 credit

GET https://transcriptapi.com/api/v2/youtube/channel/search?channel=@TED&q=climate+change&limit=30
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Validation
channel	yes	@handle, channel URL, or UC... ID
q	yes	1-200 chars
limit	no	1-50 (default 30)

GET /api/v2/youtube/playlist/videos — 1 credit/page

# First page
GET https://transcriptapi.com/api/v2/youtube/playlist/videos?playlist=PL_PLAYLIST_ID
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

# Next pages
GET https://transcriptapi.com/api/v2/youtube/playlist/videos?continuation=TOKEN
Authorization: Bearer $TRANSCRIPT_API_KEY
User-Agent: YourAgent/1.0

Param	Required	Validation
playlist	conditional	Playlist URL or ID (PL/UU/LL/FL/OL prefix)
continuation	conditional	non-empty string

Credit Costs

Endpoint	Cost
transcript	1
search	1
channel/resolve	free
channel/search	1
channel/videos	1/page
channel/latest	free
playlist/videos	1/page

Errors

Code	Meaning	Action
401	Bad API key	Check key, re-run setup
402	No credits	Top up at transcriptapi.com/billing
403/1010	Cloudflare block	Add or fix User-Agent header
404	Not found	Video/channel/playlist doesn't exist or no captions
408	Timeout/retryable	Retry once after 2s
422	Validation error	Check param format
429	Rate limited	Wait, respect Retry-After

Tips

• When user shares YouTube URL with no instruction, fetch transcript and summarize key points.
• Use channel/latest (free) to check for new uploads before fetching transcripts — pass @handle directly.
• For research: search → pick videos → fetch transcripts.
• Free tier: 100 credits, 300 req/min. Starter ($5/mo): 1,000 credits, 300 req/min.

Copy-paste examples

Every request in this file as a ready-to-run one-liner: references/curl-examples.md