What Are the Dependencies for Diagram Design? A Complete Guide to Installation and Requirements

Diagram Design requires only Python ≥3.9 and optionally Playwright for PNG export—all other functionality uses the Python standard library.

Diagram Design is intentionally built as a lightweight, pure-Python project that minimizes external dependencies. According to the cathrynlavery/diagram-design source code, the repository relies almost entirely on built-in Python modules, making it easy to install and maintain across different environments. This guide covers exactly what you need to run each feature of the project.

Core Dependencies: Python Standard Library Only

The foundation of Diagram Design requires no third-party packages. All core functionality—including type definitions, import tools, and validation—is implemented using only Python's built-in modules.

The following standard library modules power the main scripts:

• argparse – Command-line interface handling
• json – Configuration and data parsing
• re – Pattern matching for text extraction
• pathlib – Cross-platform file path operations
• html and html.parser – HTML processing and validation
• urllib – URL handling and network operations
• base64, zlib, xml.etree.ElementTree – Draw.io file parsing
• dataclasses, collections – Data structures and utilities

These modules are used across the entire codebase, from skills/diagram-design/scripts/drawio_extract.py for Draw.io import to skills/diagram-design/scripts/self_check.py for built-in validation.

Optional Dependency: Playwright for PNG Export

The only external package required for full functionality is Playwright. This dependency becomes necessary only when you need to export diagrams to PNG format.

As documented in the README's Export to PNG / SVG section, the scripts/export-diagram workflow uses Playwright to rasterize SVG output into PNG images.

Installing Playwright for Diagram Design PNG Export

# Install the Playwright Python client

pip install playwright

# Download the required browser binaries (Chromium is used by Diagram Design)

playwright install chromium

Without Playwright installed, all other Diagram Design features continue to work normally. You can create, validate, and export SVG diagrams without any additional setup.

Dependency Breakdown by Feature

Feature	Required Packages	Source Location
Core functionality and type definitions	Python ≥3.9 (standard library)	skills/diagram-design/ (e.g., SKILL.md, references/*.md)
Draw.io import and conversion	Python standard library (base64, zlib, xml.etree.ElementTree)	skills/diagram-design/scripts/drawio_extract.py
Mermaid import and conversion	Python standard library (json, re, dataclasses)	skills/diagram-design/scripts/mermaid_extract.py
Self-check validation	Python standard library (html.parser, collections)	skills/diagram-design/scripts/self_check.py
CI verification suite (geometry, treemap, motion tests)	Python standard library	scripts/verify-*.py and scripts/test-*.py
PNG export	Playwright (pip install playwright)	scripts/export-diagram (documented in README)
Icon generation from static SVG assets	No additional packages	scripts/build-icons.py

Running Diagram Design Without External Dependencies

Most common use cases require zero package installation beyond Python itself. Here's how to validate a diagram file using only built-in modules:

# Run self-check validation—no pip install required

python3 skills/diagram-design/scripts/self_check.py path/to/diagram.html

# Expected output on success:

# OK

This script, located at skills/diagram-design/scripts/self_check.py, demonstrates the project's commitment to standard-library-only implementations for core tooling.

Key Files for Understanding Dependencies

File	Purpose	Dependencies Used
README.md	Installation documentation	Documents Playwright requirement for export
skills/diagram-design/scripts/drawio_extract.py	Draw.io import and conversion	base64, zlib, xml.etree.ElementTree
skills/diagram-design/scripts/mermaid_extract.py	Mermaid diagram extraction	json, re, dataclasses
skills/diagram-design/scripts/self_check.py	HTML validation and verification	html.parser, collections
scripts/verify-*.py and scripts/test-*.py	CI verification and testing	Various standard library modules
scripts/build-icons.py	Static icon generation from SVG assets	None (file I/O only)

Summary

• Diagram Design dependencies are minimal by design: Python ≥3.9 is the only hard requirement.
• Playwright is the sole optional dependency, needed exclusively for PNG export functionality via scripts/export-diagram.
• All import tools (Draw.io, Mermaid), validation scripts, and CI verification run on standard library modules.
• No configuration files, requirements.txt, or pyproject.toml dependency declarations are needed for core usage.

Frequently Asked Questions

Does Diagram Design require a requirements.txt file?

No. Because Diagram Design uses only Python's standard library for all core functionality, no requirements.txt or pyproject.toml dependency declaration is necessary. You only need to install Playwright separately if you intend to export diagrams to PNG format.

What Python version is required for Diagram Design?

Python 3.9 or newer is required. This ensures compatibility with modern type hint syntax and standard library features used throughout the codebase, particularly in skills/diagram-design/scripts/mermaid_extract.py which leverages dataclasses and other 3.9+ conventions.

Can I use Diagram Design without installing Playwright?

Yes. Playwright is only required for PNG export. You can create diagrams, import from Draw.io and Mermaid formats, run validation with self_check.py, and export to SVG format without any external packages installed.

Where is the Playwright dependency documented in the Diagram Design repository?

The Playwright requirement is documented in the Export to PNG / SVG section of the main README.md, which describes the installation steps and browser binary setup needed for rasterizing SVG output to PNG images.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}