YouTube

YouTube Summarizer API

AI summary from YouTube's published captions — same source as /transcript.

Fetches YouTube's published captions (same engine as /transcript — not speech-to-text) and returns an AI summary, key points, topics, and sentiment. When the video has no caption tracks, you get the same diagnostic 404 as /transcript (code, reason, availableLanguages, hasAutoCaptions) and are charged 0 credits — never 3. Long live streams often lack auto-captions. Flat 3 credits only when a summary is returned.

Docs: https://captapi.com/apis/youtube-summarizer

get/v1/youtube/summarize

Request

  • Base URL: https://api.captapi.com
  • URL: https://api.captapi.com/v1/youtube/summarize
  • Auth: one of:
    • HTTP bearer
    • API key in header X-API-Key

Query parameters

urlstring required

Public YouTube video URL, e.g. https://youtube.com/watch?v=ID. Not a TikTok/Instagram/Facebook URL. The URL platform must match this endpoint's platform. Do not pass cross-platform URLs, e.g. YouTube to TikTok, Instagram to Facebook, LinkedIn to X/Twitter, or Pinterest to Rumble.

languagestring

Preferred caption language as an ISO code, e.g. "en". Defaults to auto-detect.

cacheboolean

Set true to serve from the 24h response cache (0 credits on hit). Default false — always fetch fresh.

Response

Success. The data object for this endpoint.

successunknown required

Changes

No recorded changes to this operation across all 3 revisions of this API.