# How to Use book-to-skill with GitHub Copilot CLI > Learn to use book-to-skill with GitHub Copilot CLI to convert documents into usable skills. Follow our two-stage pipeline for seamless integration. - Repository: [Virgilio Junior/book-to-skill](https://github.com/virgiliojr94/book-to-skill) - Tags: how-to-guide - Published: 2026-08-27 --- **Use book-to-skill to extract and convert documents into deterministic skills that GitHub Copilot CLI can consume through a two-stage pipeline: extraction via [`scripts/extract.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/scripts/extract.py) and generation to `~/.copilot/skills//`.** The book-to-skill project transforms books, papers, and documents into structured, queryable skills for AI agents. According to the [virgiliojr94/book-to-skill](https://github.com/virgiliojr94/book-to-skill) source code, this open-source tool implements a **deterministic pipeline** that ensures identical inputs always produce identical skill files—critical for reproducible agent behavior in GitHub Copilot CLI. ## Understanding the book-to-skill Architecture The architecture separates concerns into two distinct stages: **extraction** and **generation**. ### Stage 1: Document Extraction The extraction layer lives in the Python package under `book_to_skill/` and is invoked through the thin shim [[`scripts/extract.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/scripts/extract.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/scripts/extract.py). This module delegates to [[`book_to_skill/cli.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/cli.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/book_to_skill/cli.py) for argument parsing and multi-source handling. Format-specific parsers reside in [`book_to_skill/parsers/`](https://github.com/virgiliojr94/book-to-skill/tree/master/book_to_skill/parsers) and handle: - PDF via [`pdf.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/pdf.py) - EPUB via [`epub.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/epub.py) - DOCX via [`docx.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/docx.py) - HTML, RTF, Calibre conversions, and plain text Security hardening occurs in [[`book_to_skill/sanitize.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/sanitize.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/book_to_skill/sanitize.py), which strips zero-width Unicode characters and implements DOCX XXE guards. The extractor writes two artifacts to a temporary work directory: - [`full_text.txt`](https://github.com/virgiliojr94/book-to-skill/blob/main/full_text.txt) — concatenated, source-marked text - [`metadata.json`](https://github.com/virgiliojr94/book-to-skill/blob/main/metadata.json) — page, word, token counts plus generated table of contents ### Stage 2: Skill Generation The generator follows the specification in [[`SKILL.md`](https://github.com/virgiliojr94/book-to-skill/blob/main/SKILL.md)](https://github.com/virgiliojr94/book-to-skill/blob/master/SKILL.md), executing deterministic steps: 1. Content-type detection 2. Cost estimation 3. Structure analysis 4. Depth selection 5. Per-chapter summarization 6. Glossary and pattern generation 7. Final [`SKILL.md`](https://github.com/virgiliojr94/book-to-skill/blob/main/SKILL.md) assembly Output lands in host-specific directories. For GitHub Copilot CLI, this defaults to `~/.copilot/skills//`. ## Installing book-to-skill for Copilot CLI Integration Before generating skills, verify your environment meets dependencies: ```bash # Check for required external tools python scripts/extract.py --check ``` The [[`book_to_skill/dependencies.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/dependencies.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/book_to_skill/dependencies.py) module probes for optional tools like `pdftotext` and `ebook-convert`, generating a readiness report. ## Generating Skills for GitHub Copilot CLI ### Basic Single-Document Extraction Convert a PDF into a Copilot-usable skill: ```bash # Extract a single PDF and name the skill "my-book-skill" ./book-to-skill ~/documents/my-book.pdf my-book-skill ``` The tool creates `~/.copilot/skills/my-book-skill/` containing the structured skill files. ### Multi-Source Skill Creation Combine multiple documents into one unified skill: ```bash # Extract multiple files (PDF + Markdown) into one skill ./book-to-skill ~/papers/paper1.pdf ~/notes/notes.md unified-research # Process an entire folder of supported documents ./book-to-skill ~/project-docs/ project-knowledge # Use glob patterns for batch processing ./book-to-skill "~/books/*.epub" my-library ``` The [[`book_to_skill/utils.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/utils.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/book_to_skill/utils.py) module handles source resolution, chapter detection, and runner orchestration for multi-source scenarios. ## Reloading and Using Skills in GitHub Copilot CLI GitHub Copilot CLI scans skill folders only at startup. After generating a skill, you **must reload** the skill cache: ```bash # Make Copilot aware of the new skill /skills reload # refresh the skill cache /skills list # verify "my-book-skill" appears ``` Once listed, invoke the skill using its slug: ```bash # Show the skill's purpose and top-level summary /my-book-skill # List available chapters /my-book-skill "list chapters" # Dive into a specific chapter /my-book-skill ch05 ``` ## Validating and Securing Generated Skills The repository includes validation tools to ensure skill integrity: ```bash # Validate SKILL.md against Copilot-specific rules python tools/validate_skill.py --lens copilot ~/.copilot/skills/my-book-skill/SKILL.md # Scan for prompt injection, hidden Unicode, or authority-widening tags python tools/scan_generated_skill.py ~/.copilot/skills/my-book-skill/ ``` These tools reference [[`tools/validate_skill.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/tools/validate_skill.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/tools/validate_skill.py) and [[`tools/scan_generated_skill.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/tools/scan_generated_skill.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/tools/scan_generated_skill.py) for implementation details. ## Configuring Output Paths and Extensions Control supported formats and default locations through [[`book_to_skill/config.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/config.py)](https://github.com/virgiliojr94/book-to-skill/blob/master/book_to_skill/config.py). This module declares: - Supported file extensions - Default output directory patterns - Host-specific path conventions (Copilot, Claude, Amp) ## Summary - **book-to-skill** implements a two-stage pipeline (extraction → generation) for converting documents into agent-ready skills - The **extractor** uses format-specific parsers in `book_to_skill/parsers/` with security hardening via [`sanitize.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/sanitize.py) - Skills for **GitHub Copilot CLI** deploy to `~/.copilot/skills//` and require `/skills reload` to become available - **Multi-source inputs** are supported: single files, multiple files, directories, and glob patterns - **Validation tools** ensure skill integrity and guard against prompt injection vulnerabilities ## Frequently Asked Questions ### Where does book-to-skill place generated skills for Copilot CLI? By default, skills land in `~/.copilot/skills//` as configured in [`book_to_skill/config.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/config.py). The `` matches the skill name you provide as the final argument to the extraction command. ### Why does my new skill not appear in `/skills list` immediately? GitHub Copilot CLI caches skills at startup. Run `/skills reload` to refresh the cache after generating a new skill. This is a host-specific behavior documented in the Copilot CLI specification. ### Can I combine multiple PDFs, EPUBs, and Markdown files into one skill? Yes. Pass multiple paths, directories, or glob patterns to `book-to-skill`. The [`book_to_skill/utils.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/book_to_skill/utils.py) module orchestrates source resolution and chapter detection across heterogeneous formats, producing unified output. ### How does book-to-skill handle security in extracted documents? The pipeline implements multiple hardening measures: zero-width Unicode stripping in [`sanitize.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/sanitize.py), DOCX XXE attack prevention, and subprocess argument sanitization. The optional [`tools/scan_generated_skill.py`](https://github.com/virgiliojr94/book-to-skill/blob/main/tools/scan_generated_skill.py) performs post-generation audits for prompt injection vectors.