diagram-design

diagram-design is a skill for Claude Code from MichelKerkmeester/skilled-agent-harness_spec-driven-loops. It costs 223 tokens per session (8,637 once invoked), scanned A, original, MIT.

A skill for creating technical and product diagrams as self-contained HTML files with inline graphics and styling.

In plain words
What is it for?
It helps create architecture diagrams, flowcharts, sequence diagrams, data models, timelines, charts, and other structured visuals.
Why use it?
It provides consistent rules for choosing diagram types, layouts, detail levels, and visual styles.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the diagram-design plugin — 1 skill, 3 commands shipped together

Good fit It helps create architecture diagrams, flowcharts, sequence diagrams, data models, timelines, charts, and other structured visuals.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add MichelKerkmeester/skilled-agent-harness_spec-driven-loops --skill diagram-design
Clone the repo
git clone --depth 1 https://github.com/MichelKerkmeester/skilled-agent-harness_spec-driven-loops

Made for: Claude Code.

Or install diagram-design, the plugin that ships this one along with the rest of its 1 skill, 3 commands.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for diagram-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design/github.svg)](https://agentmods.dev/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design)
Your own site
<a href="https://agentmods.dev/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design"><img src="https://agentmods.dev/badge/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for diagram-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design"><img src="https://agentmods.dev/badge/skills/michelkerkmeester/skilled-agent-harness_spec-driven-loops/diagram-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 223 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,637 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00223 $0.08637
Opus 5 $0.00112 $0.04319
Sonnet 5 $0.00045 $0.01727
Haiku 4.5 $0.00022 $0.00864

Measured 7d ago against content hash be10184d3bfb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

diagram-design scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

specs/sk-doc/028-sk-create-diagram/context/skills/diagram-design/SKILL.md · 540 lines

How it starts

The opening of the file, as written. The whole thing — 540 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Diagram Design

Create visual diagrams as self-contained HTML files with inline SVG and CSS, following an opinionated editorial design system.

Twenty-seven diagram types. One shared design system, complexity budget, and taste gate. Type-specific conventions live in references/ and are loaded only when you pick a type.


0. First-time setup — style guide gate

Before generating your first diagram in a new project, verify the style guide has been customized.

Open references/style-guide.md and check the default tokens. If they're still the shipped defaults (paper #faf7f2, ink #1c1917, accent #b5523a rust), pause and ask the user:

"This is your first Schematic in this project. The style guide is still at the default (neutral stone + rust). Do you want to customize it to match your brand first? Options: (a) pull from your website URL, (b) extract from an installed skill, (c) extract from a local folder / design-system directory, (d) paste tokens manually, (e) proceed with the default for now."

Then branch:

  • (a) → follow references/onboarding.md § URL to fetch the site, extract palette + fonts, propose a diff, and write style-guide.md.
  • (b) → follow references/onboarding.md § Skill — ask which skill, read its SKILL.md / CSS / token files, map to semantic roles, propose diff.
  • (c) → follow references/onboarding.md § Folder — ask for the path, glob for CSS/JSON/MD token files, map to semantic roles, propose diff.
  • (d) → accept the user's tokens and write them into style-guide.md under a new "Custom tokens" section.
  • (e) → proceed; optionally remind the user they can run onboarding later.

Once the style guide has been customized (or the user explicitly opted for default), skip this gate on subsequent runs. A simple way to detect customization: if the accent value in style-guide.md differs from #b5523a, assume custom.

Read the full file on GitHub · 540 lines

Files

What ships with it

60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago Changed · +1 lines be10184d3bfb
  2. 9d ago First seen · 539 lines · 223 tokens per session scan A 5decdfe9fa67

Subscribe to this mod's changes

diagram-design is a skill published in the GitHub repository MichelKerkmeester/skilled-agent-harness_spec-driven-loops (35 stars, last pushed today), licensed MIT. It adds 223 tokens to every session and 8,637 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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