Diagramming Code

Q: What is a Claude Code skill and how does the Diagramming Code skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Diagramming Code is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Security · Sub-category: security-misc · Last updated: 2026-05-21

Generates Mermaid diagrams from Trailmark code graphs. Produces call graphs, class hierarchies, module dependency maps, containment diagrams, complexity heatmaps, and attack surface data flow visualizations. Use when visualizing code architecture, drawing call graphs, generating class diagrams, creating dependency maps, producing complexity heatmaps, or visualizing data flow and attack surface paths as Mermaid diagrams.

From the source SKILL.md

Generates Mermaid diagrams from Trailmark's code graph. A pre-made script handles Mermaid syntax generation; Claude selects the diagram type and parameters.

What this skill does

Diagramming Code is a community-contributed Claude Code skill in the security-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/diagramming-code/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when visualizing code architecture, drawing call graphs, generating class diagrams, creating dependency maps, producing complexity heatmaps, or visualizing data flow and attack surface paths as Mermaid diagrams.

Who uses this skill

The Diagramming Code Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 118,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/diagramming-code
curl -L https://claudskills.com/skills/diagramming-code/SKILL.md \
  -o ~/.claude/skills/diagramming-code/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/diagramming-code/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/diagramming-code/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\diagramming-code\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Diagramming Code Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/diagramming-code/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Diagramming Code skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Diagramming Code skill?

Use Diagramming Code when your Claude Code task falls under the Security category — specifically in the security misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Diagramming Code" or describe the task and let Claude pick). Browse related skills at /category/security/.

What is a Claude Code skill and how does the Diagramming Code skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Diagramming Code is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/seikaikyo/dash-skills/blob/HEAD/external/trailofbits-security/trailmark/skills/diagramming-code/SKILL.md
Author: seikaikyo

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

seikaikyo. (2026). Diagramming Code [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/diagramming-code/

BibTeX

@misc{diagramming-code-2026,
  author    = {seikaikyo},
  title     = {Diagramming Code [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/diagramming-code/}
}

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