YouTube Live Chat Highlights — Stream Peak & Clip Finder

What does YouTube Live Chat Highlights do?

Give it the URL of a finished YouTube live stream (archive with chat replay) and it returns, as structured JSON:

• 🔥 Highlight peaks — the moments where live chat exploded, detected from a 5-minute rolling window over the full chat replay
• ✂️ Clip-ready timestamps — each peak comes with a youtu.be/...?t= link and a YouTube-chapter-format label, pre-shifted (default −15s) because chat reacts after the moment happens
• 📊 Per-minute heatmap of chat activity and engagement dips (the boring parts)
• 🔍 Keyword hits — find viewers saying "clip this!", a character name, anything you specify
• 🤖 AI analysis (full mode) — per-peak mood, event hypothesis ("what probably happened on stream here"), sentiment ratios (pos/neg/neu) and up to 5 representative comments, powered by Claude

It analyzes the viewers' actual reactions, not the video pixels — which makes it fast, cheap, and language-aware (built and tested on Japanese VTuber streams: 草, w, 888, てぇてぇ are understood; English chat works too).

No video is ever downloaded — only the public chat replay.

Why use it?

You are...	You get...
A clip maker (切り抜き師) or their AI agent	The best 10 moments of a 5-hour stream in ~10 minutes, with ready-to-seek URLs — instead of scrubbing the whole VOD
A VTuber agency / MCN analyst	Automated per-stream engagement reports: peaks, dips, sentiment, superchat counts
A streamer	"Where did yesterday's stream hit?" for planning, thumbnails and chapters
An AI agent builder	Clean JSON via Apify API/MCP — pipe peaks into a clip-cutting Actor or an LLM summarizer

How to use it

1. Paste a YouTube URL of a finished live stream (chat replay must be enabled)
2. Pick a mode: stats (fast, cheap) or full (adds AI mood & sentiment)
3. Run — results land in the dataset as one JSON object (download as JSON, CSV, Excel...)

Works out of the box from the Apify Console, API, CLI, or as an MCP tool from Claude, Cursor and other AI agents.

Input

{
  "video_url": "https://www.youtube.com/watch?v=XXXXXXXXXXX",
  "mode": "full",
  "peak_count": 10,
  "clip_shift_seconds": -15,
  "keywords": ["clip this", "切り抜き"],
  "language_hint": "ja"
}

Output (dataset item, abridged)

{
  "video": {
    "id": "XXXXXXXXXXX",
    "title": "【World Cup】Watch-along!",
    "duration_s": 11380,
    "total_messages": 67597,
    "superchat_count": 14
  },
  "heatmap_per_min": [{ "min": 0, "count": 12 }, ...],
  "peaks": [
    {
      "rank": 1,
      "start_s": 10800,
      "end_s": 11100,
      "message_count": 3631,
      "mood": "熱戦の終了に沸く興奮と拍手喝采",
      "hypothesis": "接戦の名勝負が終了し、視聴者が賞賛コメントを大量に送っている",
      "sentiment": { "pos": 70, "neg": 12, "neu": 18 },
      "representative_comments": [
        { "text": "最高の試合だった", "sentiment": "pos" }
      ],
      "clip_recommendation": {
        "start_s": 10785,
        "end_s": 11115,
        "url": "https://youtu.be/XXXXXXXXXXX?t=10785",
        "chapter_format": "2:59:45 ピーク#1（3631コメント/5分）"
      }
    }
  ],
  "sentiment_overall": { "pos": 72, "neg": 7, "neu": 21 },
  "keyword_hits": [{ "time_s": 4735.9, "author": "...", "text": "切り抜き楽しみ‼" }],
  "dips": []
}

Pricing — how much does it cost to analyze a stream?

Pay per analyzed video, not per chat message:

Event	Price	What you get
Stats analysis	$0.19 / video	Heatmap + peaks + clip timestamps + keywords + dips
Full analysis	$0.69 / video	Everything above + AI mood, event hypothesis, sentiment, representative comments
Long video surcharge (>4h)	+$0.10	Covers the extra processing for marathon streams

A 3-hour stream with 67,000 chat messages costs $0.69 flat in full mode. Per-message pricing elsewhere can cost tens of dollars for the same stream.

Tips

• Chat reacts late: keep clip_shift_seconds at −15 for gameplay, try −30 for slow-burn reactions
• peak_count: 10 is right for 2–5h streams; use 5 for short streams, up to 30 for marathons
• Language: language_hint: "en" makes AI labels English; chat itself can be any language
• Live streams still in progress are rejected (live_status check) — run it after the stream ends

FAQ & limitations

• Does it download the video? No. Only the public live chat replay (the same data you see when watching the VOD with chat open).
• What if chat replay is disabled? The run fails with a clear error — the streamer turned off chat replay for that VOD.
• Concurrent viewer counts? Not available — YouTube does not expose them in chat replay. Chat velocity is the engagement proxy.
• Membership/limited streams? Not supported — public archives only.
• Comment texts in output are limited to statistics plus a handful of representative quotes per peak, out of respect for commenters' content.

Found a bug or want a feature (Twitch? multi-video compare?) — open an issue on the Issues tab.

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日本語での説明

配信終了後のYouTubeライブのURLを渡すと、チャット反応ベースで「盛り上がりピーク・切り抜き推奨タイムスタンプ・ヒートマップ・中だるみ区間」を構造化JSONで返すActorです。fullモードではさらに、ピークごとのムード・「何が起きたかの推測」・ポジネガ比率・代表コメントをAI（Claude）が付与します。

• 5時間のアーカイブを見返さずに、切り抜きポイントTOP10が約10分で手に入ります
• youtu.be/...?t= 形式のURLとYouTubeチャプター形式のラベル付き。チャットの反応遅延を見越して開始位置を前倒し済み
• 日本語チャット文化（草・w・888・てぇてぇ・スパチャ）を理解した感情判定
• 動画本体はダウンロードしません（公開チャットリプレイのみ）
• 料金は動画1本単位: stats $0.19 / full $0.69（4時間超は+$0.10）

Claude や Cursor から MCP ツールとしてもそのまま呼べます。