---
title: "youtube-shorts-generator by anil-matcha · skilld"
canonical_url: "https://skilld.dev/gh/anil-matcha/ai-youtube-shorts-generator"
meta:
  description: "Generate viral 9:16 YouTube Shorts (or TikTok/Reels clips) from a long-form YouTube URL or local video. Triggers on requests like \"make shorts from this… From anil-matcha/ai-youtube-shorts-generator."
  "og:description": "Generate viral 9:16 YouTube Shorts (or TikTok/Reels clips) from a long-form YouTube URL or local video. Triggers on requests like \"make shorts from this… From anil-matcha/ai-youtube-shorts-generator."
  "og:title": "youtube-shorts-generator by anil-matcha"
  "twitter:description": "Generate viral 9:16 YouTube Shorts (or TikTok/Reels clips) from a long-form YouTube URL or local video. Triggers on requests like \"make shorts from this… From anil-matcha/ai-youtube-shorts-generator."
  "twitter:title": "youtube-shorts-generator by anil-matcha"
---

`

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[![anil-matcha avatar](https://skilld.dev/_img/avatar?url=https%3A%2F%2Fgithub.com%2Fanil-matcha.png%3Fsize%3D96)](https://skilld.dev/gh/anil-matcha)

# **/youtube-shorts-generator**

[@57e261e](https://github.com/Anil-matcha/AI-Youtube-Shorts-Generator/commit/57e261e6d44e91f8d3ad5172e8f39d950a8426e4 "Your agent reads SKILL.md at commit 57e261e")

by [Anil Chandra Naidu Matcha](https://skilld.dev/gh/anil-matcha)· [anil-matcha](https://skilld.dev/gh/anil-matcha)/ [ai-youtube-shorts-generator](https://skilld.dev/gh/anil-matcha/ai-youtube-shorts-generator)·5.2k stars

 948

Generate viral 9:16 YouTube Shorts (or TikTok/Reels clips) from a long-form YouTube URL or local video. Triggers on requests like "make shorts from this video", "extract viral clips from this YouTube link", "auto-clip this podcast", "find the best moments and crop vertical". Pipeline downloads the source, transcribes via MuAPI /openai-whisper, ranks highlights through a virality framework (hook / emotional peak / opinion bomb / revelation / conflict / quotable / story peak / practical value), dedupes overlapping candidates, and vertically auto-crops the top N as mp4s.

- 1 file
- 7.1 KB
- Updated 5 months ago
- [GitHub](https://github.com/Anil-matcha/AI-Youtube-Shorts-Generator/blob/main/.claude/skills/youtube-shorts-generator/SKILL.md "View SKILL.md on GitHub")
- [3 warnings](#third-party-checks "Third-party checks: 3 warnings · 3 checks · Risk MEDIUM")

## SKILL.md

7.1 KB

**≈150** tokens always: the name and description. **≈1.7k** when used: this file.

## YouTube Shorts Generator

End-to-end pipeline that turns one long video into N viral-ready vertical clips. Each clip ships with a viral score (0–100), an opening hook line, and a one-sentence reason it should perform.

Reference implementation: https://github.com/SamurAIGPT/AI-Youtube-Shorts-Generator

### When to use this skill

- "Generate shorts from this YouTube video"
- "Find the most viral 60-second clips in this podcast"
- "Auto-crop this interview to 9:16"
- "Give me TikTok clips from this lecture"

If the user only wants transcription, summarization, or thumbnails — this is the wrong skill.

### Inputs to collect before running

Ask once, then proceed:

1. **Source** — YouTube URL (preferred) or path/URL to an mp4
2. **`num_clips`** — default 3
3. **`aspect_ratio`** — default `9:16` (also: `1:1`, `4:5`)
4. **`language`** — default auto-detect (forwarded to MuAPI Whisper as ISO-639-1)
5. **Output JSON path** — optional; if set, dump full result there

If the user gave a URL and nothing else, use defaults and don't block on questions.

### Prerequisites (verify before first run)

- Python 3.10+
- A MuAPI key — set `MUAPI_API_KEY` in `.env`. Powers download, transcription, highlight ranking, and clipping. If missing, stop and ask the user for it; do not invent one.
- `pip install -r requirements.txt` inside a venv

If the repo isn't cloned yet, clone `https://github.com/SamurAIGPT/AI-Youtube-Shorts-Generator.git` into the working directory.

### Pipeline (what to execute)

Run the eight stages in order. Each maps to a module in `shorts_generator/`.

1. **Download** ( `downloader.py`) — pull the source video at the requested resolution ( `360`/ `480`/ `720`/ `1080`, default `720`).
2. **Transcribe** ( `transcriber.py`) — MuAPI `/openai-whisper` runs Whisper server-side and returns timestamped `verbose_json` segments. Billed per minute of audio.
3. **Classify content type** — LLM tags the video (podcast / interview / tutorial / vlog / lecture / monologue) and density. Tune the highlight prompt per type.
4. **Chunk if long** ( `highlights.py`) — videos > `LONG_VIDEO_THRESHOLD` (1800s default) are split into `CHUNK_SIZE_SECONDS` (1200s default) windows with `CHUNK_OVERLAP_SECONDS` (60s default) overlap so cross-boundary highlights aren't missed.
5. **Rank highlights** — LLM scans each chunk through `VIRALITY_CRITERIA`:
   - **Hook moments** — strong opening line that stops the scroll
   - **Emotional peaks** — laughter, anger, vulnerability, awe
   - **Opinion bombs** — spicy, contrarian, debate-bait takes
   - **Revelation moments** — "wait, what?" reframes
   - **Conflict** — disagreement, tension, callouts
   - **Quotable lines** — tight, screenshot-worthy phrasing
   - **Story peaks** — climax of a narrative arc
   - **Practical value** — actionable insight a viewer will save Each candidate gets `start_time`, `end_time`, `score` 0–100, `title`, `hook_sentence`, `virality_reason`. Aim for 30–75s clips unless content dictates otherwise.
6. **Dedupe** — collapse overlaps. Rule: if two candidates overlap > 50%, keep the higher score, drop the other.
7. **Top-N selection** — sort surviving candidates by score, take `num_clips`.
8. **Vertical auto-crop** ( `clipper.py`) — render each highlight at `aspect_ratio`. Auto-handles face tracking and screen recordings; no Haar cascades.

### Invocation

CLI (the standard path):

```
python main.py "<YOUTUBE_URL>" \
    --num-clips 5 \
    --aspect-ratio 9:16 \
    --output-json result.json
```

Python API (when embedding in another pipeline):

```
from shorts_generator import generate_shorts

result = generate_shorts(
    "<URL>",
    num_clips=5,
    aspect_ratio="9:16",
)
for short in result["shorts"]:
    print(short["score"], short["title"], short["clip_url"])
```

Batch mode — `urls.txt` with one URL per line:

```
xargs -a urls.txt -I{} python main.py "{}"
```

### CLI flags reference

| Flag | Default | Notes |
| --- | --- | --- |
| `--num-clips` | `3` | How many shorts to render |
| `--aspect-ratio` | `9:16` | `9:16` for TikTok/Reels, `1:1` square, anything else by flag |
| `--format` | `720` | Source download resolution |
| `--language` | auto | Whisper language code (e.g. `en`) |
| `--output-json` | — | Dump full result (transcript + all candidates + clip URLs) |

### Output schema

```
{
  "source_video_url": "...",
  "transcript": { "duration": 1873.4, "segments": [...] },
  "highlights": [ /* every candidate, before top-N cut */ ],
  "shorts": [
    {
      "title": "The one mistake that cost me $50K",
      "start_time": 124.3,
      "end_time": 187.6,
      "score": 92,
      "hook_sentence": "Nobody talks about this, but it killed my first startup...",
      "virality_reason": "Opens with a number + regret, peaks on a contrarian lesson",
      "clip_url": "https://.../short_1.mp4"
    }
  ]
}
```

When reporting back to the user, surface for each clip: rank, score, time range, title, hook, and clip URL. Skip the raw transcript unless asked.

### Tunable knobs

- `shorts_generator/highlights.py`
  - `VIRALITY_CRITERIA` — reorder or extend signals
  - `HIGHLIGHT_SYSTEM_PROMPT` — duration sweet spot, hook rules, JSON schema
  - `CHUNK_SIZE_SECONDS` — 1200s default
  - `LONG_VIDEO_THRESHOLD` — 1800s default
  - `CHUNK_OVERLAP_SECONDS` — 60s default
- `shorts_generator/config.py` (or env vars)
  - `MUAPI_POLL_INTERVAL` — 5s
  - `MUAPI_POLL_TIMEOUT` — 1800s

### Whisper transcription

Audio is transcribed by MuAPI's `/openai-whisper` endpoint (server-side `whisper-1`, billed per minute). The CLI passes `--language` straight through; leave it empty for auto-detection, or pass an ISO-639-1 code (e.g. `en`) to lock it.

### Failure modes — handle, don't paper over

- **Whisper produced no segments** — likely no detectable speech or a hard language. Retry with `--language <code>` (correct ISO-639-1) before declaring failure.
- **API key missing or rejected** — surface the exact error; never fabricate a key.
- **Job timed out** — bump `MUAPI_POLL_TIMEOUT` and retry; don't silently truncate.
- **Highlight ranker returned < `num_clips`** — return what survived dedupe with a note; don't pad with low-score filler.

### Done criteria

The skill is done when:

1. `result["shorts"]` has up to `num_clips` entries, each with a working `clip_url`.
2. The user has been shown the ranked list (score, time range, title, hook, URL).
3. If `--output-json` was set, the file exists and parses.

If any clip URL 404s on a HEAD check, re-run just the crop stage for that highlight rather than re-running the whole pipeline.

Source: [SKILL.md on GitHub](https://github.com/Anil-matcha/AI-Youtube-Shorts-Generator/blob/main/.claude/skills/youtube-shorts-generator/SKILL.md)

## Third-party checks

<details>

<summary>3 warnings1mo3 checks · Risk MEDIUM</summary>



- Gen Agent Trust Hub1mo

  The skill downloads and executes code from an external third-party repository and processes untrusted video transcripts, which presents a risk of indirect prompt injection.
- Socket1mo

  1 alert: gptAnomaly
- Snyk1mo

  Risk: MEDIUM · 2 issues

</details>

## Provenance

[Signed by skilld at 57e261e.](https://github.com/Anil-matcha/AI-Youtube-Shorts-Generator/commit/57e261e6d44e91f8d3ad5172e8f39d950a8426e4 "57e261e6d44e91f8d3ad5172e8f39d950a8426e4") This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub yesterday.

Activeupdated 5 months ago

## README badge

![README badge for anil-matcha/ai-youtube-shorts-generator](https://skilld.dev/b/anil-matcha/ai-youtube-shorts-generator?theme=light&label=0)

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