Understanding the Two Main Components of Book-to-Skill
Book-to-Skill consists of two core components: a deterministic Python extractor that parses documents into structured data, and a spec-driven generator that transforms that data into a reusable Agent Skill.
The virgiliojr94/book-to-skill repository implements a clean separation between data extraction and skill generation. This architecture allows users to process any book or document format and produce LLM-ready outputs without mixing parsing concerns with presentation logic.
The Deterministic Python Extractor
The first component handles all document ingestion and normalization. It is implemented as a deterministic Python pipeline that converts raw files—PDFs, EPUBs, DOCX, HTML, and others—into a canonical JSON representation.
The extraction logic resides in two locations:
- [
scripts/extract.py](https://github.com/virgiliojr94/book-to-skill/blob/master/scripts/extract.py) – The CLI entry point that orchestrates the extraction workflow book_to_skill/– The core package containing parsers, text sanitizers, and format handlers
This separation ensures that parsing remains reproducible and testable. The same input document always produces identical structured output, which is critical for downstream processing.
Run the extractor from the command line:
python -m book_to_skill.cli extract path/to/book.pdf --out extracted.json
The --out parameter specifies where the canonical JSON representation is saved. This file serves as the bridge to the second component.
The Spec-Driven Generator
The second component transforms extracted data into the final Agent Skill. Unlike the extractor, which operates on fixed parsing rules, the generator follows an external specification defined in [SKILL.md](https://github.com/virgiliojr94/book-to-skill/blob/master/SKILL.md).
This design provides flexibility:
- Modify output structure without touching Python code
- Version skill formats independently of the extraction engine
- Support multiple target skill formats through different spec files
Generate a skill from extracted data:
python -m book_to_skill.cli generate extracted.json --spec SKILL.md --out skill.md
The generator reads the JSON produced by the extractor, applies the rules and templates from SKILL.md, and emits a markdown file formatted for agent consumption.
How the Components Work Together
The two components form a linear pipeline:
- Extract – Document →
extracted.json(deterministic, format-agnostic) - Generate –
extracted.json+SKILL.md→skill.md(spec-driven, customizable)
This architecture mirrors classical ETL patterns: extraction handles messy real-world inputs, while generation applies business logic through configuration rather than code.
Development teams benefit from this split:
- Engineers focus on parser accuracy and performance in
book_to_skill/ - Prompt engineers or domain experts refine
SKILL.mdto control output quality - Operations cache or version
extracted.jsonto avoid re-parsing unchanged documents
Command-Line Interface Reference
Both components expose unified CLI commands under book_to_skill.cli:
| Command | Purpose | Primary Files |
|---|---|---|
extract |
Parse document to structured JSON | scripts/extract.py, book_to_skill/* |
generate |
Render JSON to Agent Skill via spec | SKILL.md |
Add --help to any command for parameter details:
python -m book_to_skill.cli --help
python -m book_to_skill.cli extract --help
python -m book_to_skill.cli generate --help
Summary
- Deterministic Python extractor – Parses documents into canonical JSON using the
book_to_skillpackage andscripts/extract.py - Spec-driven generator – Produces Agent Skills by applying
SKILL.mdtemplates to extracted data - Clean separation – Parsing logic and output formatting remain independent, enabling parallel development and flexible deployment
Frequently Asked Questions
What file formats does the Book-to-Skill extractor support?
The extractor handles PDF, EPUB, DOCX, HTML, and other common document formats through the parsing utilities in the book_to_skill/ package. Specific format support depends on the underlying libraries integrated into the extraction pipeline.
Can I customize the output format without modifying Python code?
Yes. The spec-driven generator reads rules from [SKILL.md](https://github.com/virgiliojr94/book-to-skill/blob/master/SKILL.md), allowing you to change output structure, field mappings, and formatting by editing this specification file. No changes to book_to_skill/ or scripts/extract.py are required.
Is the extraction process deterministic and repeatable?
Yes. The Python extractor is designed to produce identical JSON output for identical inputs. This determinism enables caching, regression testing, and reproducible build pipelines when processing large document collections.
Where can I find the CLI implementation for both components?
The unified command-line interface is accessed through python -m book_to_skill.cli, which exposes extract and generate subcommands. The CLI orchestration logic resides in [scripts/extract.py](https://github.com/virgiliojr94/book-to-skill/blob/master/scripts/extract.py) and supporting modules within the book_to_skill/ package.
Have a question about this repo?
These articles cover the highlights, but your codebase questions are specific. Give your agent direct access to the source. Share this with your agent to get started:
curl -s "https://instagit.com/install.md" Maintain an open-source project? Get it listed too →