content-core

Documents

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

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Source SKILL.md: https://github.com/lfnovo/content-core/blob/HEAD/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, 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	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.

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
uvx content-core extract "https://www.youtube.com/watch?v=VIDEO_ID"

# 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-4-20250514
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
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 Bash, 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 Bash 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