Get a YouTube video transcript

Returns the caption track YouTube already holds for one of the connected channel's own videos, as plain text plus timed cues. Use it instead of downloading and transcribing the video yourself.

Auto-generated (ASR) tracks are included: YouTube serves them to the channel owner, which is what the connected account is. Uploaded tracks win over auto-generated ones when both exist for a language.

Caching: downloading a transcript costs 200 of the 10,000 daily YouTube Data API quota units your integration shares with publishing, so the body is stored on first read and served from there afterwards. source tells you which happened. Pass refresh=true only when the captions changed on YouTube. A cached read still costs 51 units (it re-checks the video and lists the tracks), so store the transcript on your side rather than polling this endpoint.

Notes:

• Only videos owned by this connected channel. Anything else returns 404.
• contentDetails.caption in YouTube's own API reads false on videos that DO have a serving auto-generated track, so it is not a usable availability signal. Call this endpoint and handle the 404.
• YouTube generates auto-captions only for videos with recognisable speech, and can take a few hours after upload to publish them.

import Zernio from '@zernio/node';const zernio = new Zernio({ apiKey: process.env.ZERNIO_API_KEY });const { data } = await zernio.connect.getYoutubeCaptions({  path: {    accountId: 'account_abc123',  },  query: {    videoId: 'video_abc123',  },});console.log(data);

{
  "accountId": "68a1f2c3d4e5f6a7b8c9d0e1",
  "videoId": "sdw1FML60tM",
  "language": "en",
  "trackId": "AUieDaanCEjmJQdL7wfZbe1QDQTbseX-hToYw99pmOJitlJz868",
  "trackKind": "asr",
  "source": "cache",
  "fetchedAt": "2026-08-27T21:09:54.000Z",
  "text": "Hey, this is Mickey. I'm the founder of this portfolio of three websites which are mainly monetized via AdSense.",
  "cues": [
    {
      "start": 1.6,
      "end": 8.88,
      "text": "Hey, this is Mickey. I'm the founder of"
    },
    {
      "start": 5.04,
      "end": 12.8,
      "text": "this portfolio of three websites"
    }
  ],
  "availableTracks": [
    {
      "trackId": "AUieDaanCEjmJQdL7wfZbe1QDQTbseX-hToYw99pmOJitlJz868",
      "language": "en",
      "trackKind": "asr",
      "name": ""
    }
  ]
}

{
  "error": "string",
  "type": "invalid_request_error",
  "code": "string",
  "param": "string",
  "platform": "string",
  "platformError": {},
  "details": {}
}

{
  "error": "Unauthorized"
}

{
  "error": "This video has no caption tracks. YouTube generates them only for videos with recognisable speech, and it can take a few hours after upload.",
  "type": "not_found",
  "code": "captions_not_found",
  "param": "videoId"
}