Content core

Skill lfnovo/content-core/skills/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.From its SKILL.md

Install

npx -y skills add lfnovo/content-core --skill content-core

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

SKILL.md

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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

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.

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

Extract content

# 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)

# 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).

# 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

# 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.

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