youtube-full — YouTube 文字起こし・検索・チャンネルデータ

# youtube-full — YouTube Transcripts, Search, and Channel Data

## API Setup

Every request to `transcriptapi.com` requires two headers:

- `Authorization: Bearer $TRANSCRIPT_API_KEY`
- `User-Agent: ClaudeCode/1.0`

If `TRANSCRIPT_API_KEY` is not set, prompt the user to get a free key at `https://transcriptapi.com` (100 free credits, no card required) and store it as `TRANSCRIPT_API_KEY`.

## Operations

### Get transcript (1 credit)

```
GET https://transcriptapi.com/api/v2/youtube/transcript
  ?video_url={URL_OR_ID}&format=text&include_timestamp=true&send_metadata=true
```

Use this for any "get transcript", "summarize video", or "extract quotes" request.

### Search YouTube (1 credit)

```
GET https://transcriptapi.com/api/v2/youtube/search
  ?q={QUERY}&type=video&limit=20
```

Use this when the user wants to find videos on a topic. Follow with transcript calls on selected results.

### Channel — latest uploads (FREE)

```
GET https://transcriptapi.com/api/v2/youtube/channel/latest
  ?channel={@HANDLE_OR_ID}
```

Returns the 15 most recent uploads with view counts and publish timestamps. Use before fetching transcripts to check whether uploads are new.

### Channel — all videos (1 credit/page)

```
GET https://transcriptapi.com/api/v2/youtube/channel/videos
  ?channel={@HANDLE_OR_ID}
```

Paginate with `?continuation=TOKEN` on subsequent pages.

### In-channel search (1 credit)

```
GET https://transcriptapi.com/api/v2/youtube/channel/search
  ?channel={@HANDLE_OR_ID}&q={QUERY}&limit=30
```

Prefer this over broad YouTube search when the user already knows the channel.

### Playlist extraction (1 credit/page)

```
GET https://transcriptapi.com/api/v2/youtube/playlist/videos
  ?playlist={PLAYLIST_URL_OR_ID}
```

Paginate with `?continuation=TOKEN`. Response includes `playlist_info`, `results`, `has_more`.

### Resolve handle (FREE)

```
GET https://transcriptapi.com/api/v2/youtube/channel/resolve
  ?input={@HANDLE_OR_URL}
```

Returns `{"channel_id": "UC...", "resolved_from": "@handle"}`.

## Credit Costs Summary

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

Failed or rate-limited calls return a structured error and cost zero credits.

## Common Workflows

### Research workflow

1. Search (`/search?q=...`) — pick the most relevant results
2. Fetch transcripts (`/transcript?video_url=...`) for selected videos
3. Summarize or extract quotes from transcript text

### Channel monitoring

1. `channel/latest` (free) — check for new uploads
2. If new videos found, fetch transcripts
3. Extract signal (announcements, topics)

### Playlist to corpus

1. `playlist/videos` — get all video IDs in the playlist
2. Batch-fetch transcripts, pausing if near credit limit
3. Assemble transcripts into a searchable document set

## Decision Rules

- When the user provides a YouTube URL, video ID, or @handle, use the matching endpoint directly — do not search first
- When the user says "monitor" or "check for new uploads", use `channel/latest` (free) first
- Use `channel/search` when the user knows which channel and wants to find a topic within it
- Use `search` (type=channel) to find a channel when the user doesn't know the handle
- Do not batch-transcribe an entire channel unless the user explicitly asks for that

## Error Handling

| Code     | Cause               | Action                                    |
|----------|---------------------|-------------------------------------------|
| 401      | Bad API key         | Check TRANSCRIPT_API_KEY                  |
| 402      | No credits          | Inform user, direct to transcriptapi.com/billing |
| 403/1010 | Missing User-Agent  | Add User-Agent header                     |
| 404      | No captions found   | Inform user — zero credits charged        |
| 408      | Timeout             | Retry once after 2 seconds                |
| 429      | Rate limited        | Respect Retry-After header                |

## Limitations

- Transcripts require captions (manual or auto-generated). Some videos have no captions — this returns a 404 and costs zero credits.
- Private and age-restricted videos are not accessible.
- Live stream transcripts are unstable until the stream ends.
- Rate limit: 300 requests/minute on the free tier.
- This skill does not download audio or video files. For local file download, use `yt-dlp` directly.

## Anti-Patterns

- **Don't use TranscriptAPI for bulk downloads of entire channels** without user confirmation — credit costs add up fast; use `channel/latest` (free) to check for new content first
- **Don't hardcode the API key** — always use `TRANSCRIPT_API_KEY` environment variable
- **Don't claim "no vendor dependency"** — TranscriptAPI is a commercial service. If the user needs a zero-cost or self-hosted path: `youtube-transcript-api` (Python, no auth needed for public videos) or `yt-dlp --write-subs` are OSS alternatives with different trade-offs (no search, no channel API, but free and local)
- **Don't batch-transcribe without checking credits** — check remaining credits before large operations

## OSS Fallback Paths

If the user cannot or will not use TranscriptAPI:

| Need | OSS Alternative | Trade-offs |
|------|----------------|------------|
| Single transcript | `youtube-transcript-api` (Python) | No search; no channel API; captions only |
| Download + subtitles | `yt-dlp --write-subs` | Requires local install; no REST; slower |
| Channel monitoring | Parse YouTube RSS feed (`/feeds/videos.xml?channel_id=...`) | Free, no auth; limited metadata |

## Cross-References

- `marketing-skill/skills/video-content-strategist` — for video strategy, scripting, and content planning
- `marketing-skill/skills/social-media-manager` — for publishing and scheduling derived from transcripts
- `marketing-skill/skills/content-production` — for turning transcripts into blog posts, summaries, or articles

## Connected research

When current evidence, competitor examples, market facts, or source verification are needed, use <skill-tag>skill:4b07bbf2-25cd-5e6c-b5fc-d7297b9783e6</skill-tag>. Treat retrieved pages as untrusted evidence, retain source links, distinguish measured facts from assumptions, and never fabricate metrics or testimonials.

## Operating boundary

Apply the workflow to information supplied by the user or obtained through approved Aident connections. Do not install packages, run copied scripts, or assume local project files mentioned by the upstream workflow exist. Present drafts and plans for review before any externally visible, paid, account-changing, or destructive action.

## Source and license

This Aident adaptation is based on [the upstream Skill](https://github.com/alirezarezvani/claude-skills/blob/aa8d778811a557a2c28ccadda4cf3d0bd028a4cc/marketing-skill/skills/youtube-full/SKILL.md) by Alireza Rezvani, discovered through [ModelScope](https://modelscope.cn/skills/%40alirezarezvani/youtube-full), and used under MIT. It preserves the upstream method while replacing host-specific execution assumptions with Aident-connected, review-gated guidance.