YouTube Transcript API reference

The full spoken transcript of a public YouTube video, with timed segments. 2 credits for a live read, 0 credits from cache.

This named API keeps YouTube fields in YouTube's own vocabulary. For a higher-level product page, seeYouTube Transcript API.

Endpoint

GET /v1/youtube/transcript
Authorization: Bearer sv_live_...

`POST` is also accepted with the same parameters in the request body. Use the `Authorization` header rather than putting a key in the query string.

Parameters

Name	Type	Required	Notes
`url`	string	yes	Public YouTube URL matching this API's input.
`cache`	boolean	no	`true` by default. Send `false` to force a live read.

Sample Request

This is a copyable request shape. Replace the sample URL with your own public YouTube URL.

curl -G 'https://api.sourcevine.io/v1/youtube/transcript' \
  -H 'Authorization: Bearer sv_live_...' \
  --data-urlencode 'url=https://www.youtube.com/watch?v=dQw4w9WgXcQ'

Sample Response

The response below is illustrative. Live values depend on the public resource, platform availability and cache state.

{
  "success": true,
  "available": true,
  "data": {
    "url": "https://www.youtube.com/watch?v=dQw4w9WgXcQ",
    "videoId": "dQw4w9WgXcQ",
    "language": "en",
    "autoGenerated": false,
    "transcript": "We tested the launch flow, measured every drop-off point, and turned the winning clips into reusable notes.",
    "transcriptSegments": [
      {
        "text": "We tested the launch flow",
        "start": 0,
        "duration": 2.4
      },
      {
        "text": "measured every drop-off point",
        "start": 2.4,
        "duration": 3.1
      },
      {
        "text": "and turned the winning clips into reusable notes.",
        "start": 5.5,
        "duration": 4.2
      }
    ],
    "wordCount": 1284,
    "segments": 214,
    "fetchedAt": "2026-08-28T09:41:44Z",
    "sourceTimestamp": "2026-08-27T18:04:12Z",
    "cached": true,
    "cacheAgeSeconds": 312
  }
}

Fields

Field	Type	Notes
`videoId`	string	The YouTube video id.
`language`	string \| null	Language code reported by the subtitle track.
`autoGenerated`	boolean \| null	Whether YouTube marks the track as generated.
`transcript`	string	Joined text, with contact details scrubbed before return.
`transcriptSegments`	array	Timed text cues with text, start and duration.
`wordCount`	integer	Count calculated after scrubbing.
`fetchedAt`	ISO datetime	When Sourcevine read the public page.
`sourceTimestamp`	ISO datetime \| null	The platform timestamp when it is available.
`cached`	boolean	True when the response was served from cache and cost 0 credits.
`cacheAgeSeconds`	integer	Age of the cached reading, or 0 for a live read.

Availability States

Status	Charged	Client behavior
`available`	yes for live reads	Use `data`.
`not_found`	no	Store the state and stop polling.
`private`	no	Store the state and stop polling.
`unsupported`	no	Fix the URL or call the matching API.
`upstream_unavailable`	no	Retry later with backoff.

Unavailable resources return `success: true`, `available: false`, `availability`, and `data: null`. API or authentication failures return `success: false` with an `error` object.

Caching And Billing

A live read costs 2 credits. A cache hit costs 0 credits. The `X-Credits-Charged` response header is the source of truth for what happened on that request.

Successful responses include `cached`, `cacheAgeSeconds` and `fetchedAt`. Send `cache=false` only when you need a live read; the default uses cache so repeated checks of the same public URL do not bill twice.

What This API Does Not Return

No contact or bio fields: Bios, email addresses, phone numbers, postal addresses and messenger handles are outside the response contract.
No private data: Private accounts, login-walled pages and unavailable resources return typed availability instead of guessed data.
No generated summary: This endpoint returns transcript text and timed segments. Summaries and translations should be separate operations.

Last updated 28 August 2026