Agent skill

Content Core

Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files.

MITAuto-check: notesDocuments & Office

Install Content Core

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install lfnovo/content-core content-core --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/content-core .claude/skills/content-core && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .claude/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/lfnovo/content-core/tree/main/skills/content-core

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install lfnovo/content-core content-core --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/content-core .agents/skills/content-core && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .agents/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install lfnovo/content-core content-core --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/content-core .cursor/skills/content-core && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .cursor/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/lfnovo/content-core.git --path skills/content-core

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install lfnovo/content-core content-core --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/content-core .gemini/skills/content-core && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .gemini/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install lfnovo/content-core content-core

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/content-core .github/skills/content-core && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .github/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add lfnovo/content-core --skill content-core -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install lfnovo/content-core content-core --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lfnovo/content-core.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/content-core .opencode/skills/content-core && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "content-core" agent skill from https://github.com/lfnovo/content-core/tree/main/skills/content-core into .opencode/skills/content-core/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "content-core", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: content-core
GitHub stars: 174
Token cost: ~1.5k tokens
SKILL.md length: 512 words
Files: 1
Skills in repo: 1
Repo updated: Oct 3, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files.

You need to read
SKILL.md covers Purpose, Prerequisites, Capabilities and CLI Usage, plus 3 more sections
Calls uvx, uv and curl; reaches astral.sh and youtube.com; needs OPENAI_API_KEY
Summarize content from a URL

What it does

Content Core is an agent skill from lfnovo/content-core. Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files. Use when you need to read, analyze, or summarize content from a URL, file, or media source.

Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Documents & Office. It works with Reddit, YouTube and Model Context Protocol. The repository describes itself as: Extract what matters from any media source. The licence is MIT.

When your agent uses it

You need to read
Summarize content from a URL

Example prompts

“/content-core”

Requirements

Python 3
A credential in OPENAI_API_KEY

What it can do on your machine

Read from SKILL.md and the folder at commit c4725c0. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- uvx
- uv
- curl
- sh
- brew
- pip
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- astral.sh
- youtube.com
- reddit.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names these keys or tokens, usually read from environment variables:
- OPENAI_API_KEY
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Content Core loads about 1.5k tokens when it runs. Until then it costs about 56 tokens; SKILL.md has 512 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~56
When it runs · the whole SKILL.md, loaded when a task matches: ~1.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

NotePipes a well-known installer script into a shellSKILL.md:27

- **macOS/Linux**: `curl -LsSf https://astral.sh/uv/install.sh | sh`

NotePipes a well-known installer script into a shellSKILL.md:28

`powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"`

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from lfnovo/content-core at commit c4725c0, republished under its MIT licence (© lfnovo). 512 words, ~1,532 tokens.

Download SKILL.mdSave it as .claude/skills/content-core/SKILL.md (or your agent's skills folder).

name: content-core
description: Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files. Use when you need to read, analyze, or summarize content from a URL, file, or media source.

Purpose

Content Core extracts text from external sources so you can read, analyze, or summarize them. Use it whenever you need content from a URL, PDF, document, YouTube video, Reddit post, or audio/video file.

Most extraction works without API keys. Only audio/video transcription and summarization require an LLM API key (e.g., OPENAI_API_KEY).

Prerequisites

Content Core runs via uvx (zero-install) which requires uv to be available.

Check if uv is installed

bash

uv --version

If uv is not found, help the user install it:

macOS/Linux: curl -LsSf https://astral.sh/uv/install.sh | sh
Windows: powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"
Homebrew: brew install uv
pip: pip install uv

After installation, the user may need to restart their shell or run source ~/.bashrc / source ~/.zshrc for uv to be available on PATH.

Capabilities

Source	Examples	API Key Needed
Web pages	Any URL	No
YouTube	Video transcript (`watch`, `live`, `shorts` URLs)	No
Reddit	Post + comments via public JSON	No
Documents	PDF, DOCX, PPTX, XLSX, EPUB, Markdown	No
Audio	MP3, WAV, M4A, FLAC, OGG	Yes (STT)
Video	MP4, AVI, MOV, MKV	Yes (STT)
Plain text / HTML	Raw text, auto-detects HTML	No

CLI Usage

All commands use uvx content-core which runs without installation.

bash

# Check the installed version
uvx content-core --version

Extract content

bash

# From a URL
uvx content-core extract "https://example.com"

# From a file
uvx content-core extract document.pdf

# From a YouTube video (watch, live, and shorts URLs all work)
uvx content-core extract "https://www.youtube.com/watch?v=VIDEO_ID"

# From a Reddit post
uvx content-core extract "https://www.reddit.com/r/sub/comments/POST_ID/title/"

# JSON output (includes title, content, metadata)
uvx content-core extract --format json "https://example.com"

# With a specific extraction engine
uvx content-core extract --engine firecrawl "https://example.com"
uvx content-core extract --engine docling document.pdf

Docling enrichment flags (for advanced document processing)

bash

# Enable formula extraction (LaTeX)
uvx content-core extract --engine docling --formulas paper.pdf

# Enable image descriptions and chart data extraction
uvx content-core extract --engine docling --pictures paper.pdf

# Disable OCR (faster, for PDFs with embedded text)
uvx content-core extract --engine docling --no-ocr paper.pdf

Summarize content

Requires an LLM API key (OPENAI_API_KEY or another provider).

bash

# Summarize text
uvx content-core summarize "Long text here..."

# With context to guide the summary
uvx content-core summarize --context "bullet points" "Long text..."

# Pipe extraction into summarization
uvx content-core extract "https://example.com" | uvx content-core summarize --context "key takeaways"

Configuration

bash

# View current config
uvx content-core config list

# Set persistent defaults
uvx content-core config set llm_provider anthropic
uvx content-core config set llm_model claude-sonnet-5
uvx content-core config set url_engine firecrawl

# Delete a config value
uvx content-core config delete llm_provider

# See all available config keys
uvx content-core config --help

MCP Usage

Content Core can also run as an MCP server. It may or may not be available in your current environment.

Check availability

Look for content-core in the list of available MCP servers. If available, you will have access to these tools:

extract_content

Extracts text from a URL or file. No API key needed for most sources.

extract_content(url="https://example.com")
extract_content(file_path="/path/to/document.pdf")
extract_content(url="https://youtube.com/watch?v=ID")

# With engine override (firecrawl, jina, crawl4ai, simple, docling)
extract_content(file_path="paper.pdf", engine="docling")

# With Docling enrichment
extract_content(file_path="paper.pdf", engine="docling", formulas=true, pictures=true)

summarize_content

Summarizes text using an LLM. Requires an API key.

summarize_content(content="Long text...", context="bullet points")

If summarization fails with an API key error, fall back to extract_content and return the raw content instead.

Show full SKILL.md (213 more words)Show less

Guidelines

For small/medium content (articles, short pages): prefer MCP tools if available — they are async and more efficient
For large content (long documents, full books, lengthy transcripts): prefer the CLI via a shell, redirecting output to a file (uvx content-core extract "URL" > output.md). This avoids flooding the agent's context window with large payloads. Read only the relevant sections from the file as needed.
If MCP is not available, always use the CLI via a shell with uvx content-core
For URLs: extraction works without any API key
For audio/video: requires OPENAI_API_KEY (or another STT provider key)
For summarization: requires an LLM API key
When summarization is unavailable, extract the raw content and summarize it yourself
Use --format json when you need structured metadata (title, source type, identified type)
For large documents with formulas or charts, use --engine docling with --formulas or --pictures

Error Handling

If uvx is not found: help the user install uv (see Prerequisites above)
If extraction returns empty content: the source may be behind a paywall or require authentication
If MCP tools are not available: fall back to CLI via uvx content-core
If summarization fails with API key error: use extract_content instead and summarize the content yourself
If a specific engine fails: try without --engine to use the auto-detection fallback chain

Files

Just SKILL.md in skills/content-core of lfnovo/content-core.

Open the folder on GitHubat commit c4725c0

Compare with similar skills

Content Core next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Content Core compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Content Core this skilllfnovo/content-core	174	—	~1.5k	Automated safety check: Notes	MIT	5 days ago
PullmdAeternaLabsHQ/pullmd	486	—	~2.6k	Automated safety check: Pass	AGPL-3.0	17 days ago
Influencer Discoverytigerless-labs/influencer-discovery	211	—	~2.5k	Automated safety check: Notes	None	16 days ago
Videodevourdatawhalechina/video-devour	156	—	~3k	Automated safety check: Pass	Apache-2.0	17 days ago
Social PostHao0321/claude-skill-social-post	727	—	~2.9k	Automated safety check: Pass	MIT	5 days ago
Content Trend Researcheralirezarezvani/claude-code-skill-factory	880	2 repos	~2.1k	Automated safety check: Pass	MIT	11 mo ago

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Works with

Questions about Content Core

What does Content Core do?

Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files. Content Core is an agent skill from lfnovo/content-core. Extract text content from external sources — URLs, PDFs, documents, YouTube videos, Reddit posts, and audio/video files.

When should I use Content Core?

Content Core fits situations like: you need to read; summarize content from a URL.

How do I install Content Core in Claude Code?

Run `npx skills add lfnovo/content-core --skill content-core -a claude-code`. Or copy the skill folder (skills/content-core in lfnovo/content-core) into .claude/skills/content-core in your project. Claude Code loads it when a task matches its description.

How do I install Content Core in Codex?

Run `npx skills add lfnovo/content-core --skill content-core -a codex`. Or copy the skill folder (skills/content-core in lfnovo/content-core) into .agents/skills/content-core in your project. Codex loads it when a task matches its description.

Can I use Content Core in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add lfnovo/content-core --skill content-core -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/content-core, .gemini/skills/content-core, .github/skills/content-core and .opencode/skills/content-core in your project.

What does Content Core need to run?

Going by SKILL.md and its folder, Content Core needs the command-line tools its instructions call (uvx, uv, curl, sh, brew and pip) and credentials named OPENAI_API_KEY. Our summary lists: Python 3; A credential in OPENAI_API_KEY.

Does Content Core access the network?

SKILL.md names 3 domains. In commands or code: astral.sh, youtube.com and reddit.com; the agent is likely to contact these when it follows the instructions. This is read from the text; nothing was executed.

Is Content Core safe to install?

Our automated static check of SKILL.md found notes only (pipes a well-known installer script into a shell), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.

What licence does Content Core use?

Content Core is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Content Core use?

About 1.5k tokens (SKILL.md is roughly 6.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Content Core?

Skills that share tags, products or a category with Content Core: Pullmd (AeternaLabsHQ/pullmd, 486 stars), Influencer Discovery (tigerless-labs/influencer-discovery, 211 stars), Videodevour (datawhalechina/video-devour, 156 stars) and Social Post (Hao0321/claude-skill-social-post, 727 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Content Core?

lfnovo (a GitHub user) maintains it in lfnovo/content-core, which has 174 GitHub stars. The repository was last updated on October 3, 2026.

Source: lfnovo/content-core on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Content Core

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Purpose

Prerequisites

Check if uv is installed

Capabilities

CLI Usage

Extract content

Docling enrichment flags (for advanced document processing)

Summarize content

Configuration

MCP Usage

Check availability

extract_content

summarize_content

Guidelines

Error Handling

Files

Compare with similar skills

Similar skills

Pullmd

Influencer Discovery

Videodevour

Social Post

Content Trend Researcher

Socialpost

Related

Questions about Content Core