YouTube Summarizer

Reviewed 2026-10-15productivityPrompt / Rule# youtube # transcript # summarization # video # python

Community skill that fetches a YouTube video's caption transcript with the youtube-transcript-api Python library and has the agent write a long, structured summary.

Security Reviewed

Runs a small Python script and, if you agree, pip install youtube-transcript-api; fetches captions from YouTube; writes a file only if you choose to save.

Install YouTube Summarizer in Google Antigravity

Antigravity loads skills from .agents/skills/ in your project or ~/.gemini/config/skills/ for all projects (official docs). Full guide

EasiestOption 1: paste this to your Antigravity agent

Install the "YouTube Summarizer" skill for Google Antigravity.
Follow the steps at https://www.antigravityskills.org/install/youtube-summarizer.md (source: https://github.com/sickn33/antigravity-awesome-skills/tree/main/skills/youtube-summarizer).
Before running anything, show me what you will download and whether it includes scripts, and wait for my OK.
Install it into this project (.agents/skills/) unless I say global. When done, check that Antigravity lists it as an installed skill.

The agent reads the install file, shows you what it will download and waits for your OK.

Option 2: install it yourself

1. Download the repository
```
git clone --depth 1 https://github.com/sickn33/antigravity-awesome-skills.git /tmp/ag-skills && git -C /tmp/ag-skills log -1 --format=%h
```
We reviewed commit a307264. If the second command prints a different hash, the skill may have changed since our review.
2. Copy the skill into this project (workspace skill)
```
mkdir -p .agents/skills && cp -r /tmp/ag-skills/skills/youtube-summarizer .agents/skills/
```
Run from your project root. Antigravity reads workspace skills from .agents/skills/<folder>/; this folder holds SKILL.md, README.md, CHANGELOG.md and 2 scripts (5 files).
3. Or install it for all projects (global skill)
```
mkdir -p ~/.gemini/config/skills && cp -r /tmp/ag-skills/skills/youtube-summarizer ~/.gemini/config/skills/
```
Use this instead of the previous step. Copy only the skills you need: the repo README warns that a large watched skills folder can overload Antigravity's context.
4. Check that Antigravity sees it
Antigravity app: start a new conversation and ask "What skills do you have?"; youtube-summarizer should be listed. Antigravity CLI: run /skills (/skills reload in a session that was already open).

The repository's own installer (npx agentic-awesome-skills --antigravity --skills <ids> --dry-run, README) can also install selected skills; the copy steps above use the standard Antigravity skill folders and install only this one. Python 3 is also needed, and the agent will ask before running pip install youtube-transcript-api; if you prefer, run that command yourself first.

Using Claude Code, Cursor or Codex? See other assistants below.

What is YouTube Summarizer?

youtube-summarizer is a community-contributed skill in sickn33's antigravity-awesome-skills collection (CHANGELOG: maintained by Eric Andrade). It pulls the caption text of a YouTube video, using the third-party Python package youtube-transcript-api, and asks the agent to turn it into a detailed Markdown summary. It works only for videos that have captions, auto-generated or manual; it does not listen to audio.

How to use YouTube Summarizer?

Install the skill, then give the agent a YouTube URL. It checks that python3 and youtube-transcript-api are present (and asks before running pip install), extracts the video ID, fetches the transcript, and writes the summary; at the end it offers to save the summary, optionally with the raw transcript, as a Markdown file.

Key features of YouTube Summarizer

✓We counted at a307264: the folder has 5 files: SKILL.md (426 lines, 13,275 bytes), README.md (365 lines), CHANGELOG.md (66 lines), scripts/extract-transcript.py (98 lines, 3,778 bytes) and scripts/install-dependencies.sh (28 lines, 904 bytes)
✓We counted: extract-transcript.py takes a video ID or URL, uses 2 regular expressions to find the 11-character ID (watch?v=, /embed/, /shorts/, /live/, youtu.be/, /v/), tries your language code and falls back to English, and supports a --list option that prints available transcripts as auto-generated or manual
✓We counted: install-dependencies.sh runs only pip3 install youtube-transcript-api (or pip install) and then imports the package to check it; the package version is not pinned
✓We counted: SKILL.md has a 5-step workflow (validate URL, check availability, extract transcript, generate summary, format output) and an error table with 4 cases: video not found, transcripts disabled, no transcript available, private or restricted video
✓SKILL.md tells the agent to treat the transcript text as untrusted source material, which matters because caption text is written by strangers and could contain instructions
✓The CHANGELOG lists versions 1.0.0, 1.2.0 and 1.2.1 (the last dated 2026-02-04), while SKILL.md's footer still says 1.2.0

When to use YouTube Summarizer

1Getting a written outline of a long lecture or tutorial video that has captions
2Pulling the transcript of a talk to quote or search later
3Listing which caption languages a video offers before choosing one

Source and files

Repository: sickn33/antigravity-awesome-skills (MIT)
Upstream risk label: safe
Added upstream: 2026-02-27
SKILL.md size: 13.0 KB
Files in the skill folder: CHANGELOG.md · README.md · SKILL.md · scripts
Listing synced: 2026-10-05 from commit bdacd76

Installation & Setup Guide

Agent Rules / Prompt Setup

Follow these steps (taken from the project's own docs) to configure YouTube Summarizer in your development environment.

Step 1: Claude Code (manual copy)claude

mkdir -p .claude/skills && cp -r /tmp/ag-skills/skills/youtube-summarizer .claude/skills/

Not documented per skill by the repository; this uses Claude Code's standard .claude/skills/ folder after the clone above.

Step 2: Cursor: not documented by the projectcursor

The README lists installer targets for several hosts, but gives no per-skill Cursor path, so we do not list one.

Usage Example & Verification

Prompt / Request Example

1) SKILL.md workflow: the agent validates the URL, checks the transcript is available, extracts it, then summarizes with its STAR + R-I-S-E framework and a fixed Markdown layout (header, executive summary, detailed sections, concepts, conclusion).

2) Our example: "Use the youtube-summarizer skill on https://www.youtube.com/watch?v=<VIDEO_ID>. First list the available transcript languages, then summarize in English."
-> The agent runs the --list mode of extract-transcript.py (after you confirm any install), then fetches the English transcript and writes the summary.

3) Our example: "Summarize this video and save the summary plus the raw transcript as a Markdown file."
-> SKILL.md ends with a save option that writes a .md file; check the filename it proposes before accepting.

Security Review

Static review

Reviewed Date

2026-10-15

Audited Ref / Commit

a3072641b750a1fb2f6ce695a5f984ea3d4c3ec1

Reviewer

antigravityskills.org (static review)

Runs a small Python script and, if you agree, pip install youtube-transcript-api; fetches captions from YouTube; writes a file only if you choose to save.

Full review: scope, findings, risks

Audit Scope:SKILL.md, README.md, CHANGELOG.md, scripts/extract-transcript.py and scripts/install-dependencies.sh read in full; repository README install and disclaimer sections and LICENSE, all at commit a307264 (2026-10-15). The youtube-transcript-api package was not reviewed. Static review only; nothing was executed.

Key Findings:Instruction skill with two scripts. extract-transcript.py imports re, sys and youtube_transcript_api, reads one video ID or URL from the command line and prints transcript text or an error; it does not write files. install-dependencies.sh only installs the youtube-transcript-api package with pip. SKILL.md has the agent ask before installing and offers to save a Markdown summary at the end. No credentials needed.

Identified Operational Risks & Permissions:Low to medium. The agent runs pip install of an unpinned package after you agree, the library makes network requests to YouTube, and caption text from strangers is fed to the model (prompt-injection exposure, which the skill notes). Review the file the agent proposes to save.

Both scripts were read line by line. extract-transcript.py: argument parsing, a regex video-ID parser, a call to the youtube-transcript-api library (legacy and 1.0 API both supported) and print; error branches exit with code 1. install-dependencies.sh: pip3 or pip install youtube-transcript-api, then an import check. No eval, no shell-outs, no credential handling and no file writes in either script. The network access happens inside the third-party library, which we did not read. The SKILL.md save step is an optional Markdown file chosen by the user. This is a read of the code, not a behaviour test.

Operational Notes & Known Limitations

Known Limitations

•It needs Python 3 and the youtube-transcript-api package; the agent should ask before installing it, and the install is unpinned
•Videos without captions, or with transcripts disabled, cannot be summarized; the skill does not transcribe audio
•Fetching the transcript contacts YouTube through the third-party library; we did not read that library's code, so check its documentation if this matters for your use
•SKILL.md twice refers to a "Phase 2" enhanced prompt (STAR + R-I-S-E) that is not defined as a section in this folder, so the exact prompt text is left to the agent
•The SKILL.md example output is in Portuguese and its code sample prefers Portuguese then English; the script itself defaults to English
•The skill's own Limitations section says output is not a substitute for expert review and the agent should ask when inputs are missing

Frequently Asked Questions

Is the YouTube Summarizer skill safe?

It is Markdown plus two small scripts, which we read in full. extract-transcript.py only fetches caption text and prints it; install-dependencies.sh only runs pip install youtube-transcript-api. The skill asks before installing and tells the agent to treat the transcript as untrusted. The Python package it depends on is third-party code we did not review.

How do I install YouTube Summarizer in Antigravity?

Clone sickn33/antigravity-awesome-skills, copy skills/youtube-summarizer into .agents/skills/ (or ~/.gemini/config/skills/), make sure python3 is installed, then ask "What skills do you have?" (Antigravity CLI: /skills).

Does it work on videos without captions?

No. It reads existing captions, auto-generated or manual. If the video has none, or transcripts are disabled, the skill reports an error.

Which languages does it support?

Whatever caption languages the video offers. The script tries the language code you pass and falls back to English, and its --list option shows what is available.

Is it an official Google or YouTube skill?

No. It is community-contributed to an independent collection whose README says it is not affiliated with or endorsed by Google, and it is not from YouTube.

Supported Platforms

antigravityclaude

View Source on GitHub

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