What is excalidraw-diagrams?

A workflow for creating Excalidraw files, which are editable diagrams, from a source design document. It builds diagrams with scripts, checks their layout, and keeps diagram facts tied to the source.

It helps create architecture, network, and process diagrams, including multi-frame diagrams for an Obsidian vault, from an existing design document.

Hand-made diagrams can contain invented details, broken layouts, or information that is not in the design document. This workflow makes those problems easier to detect before sharing the diagram.

excalidraw-diagrams — Skill for Claude Code by widnyana/eyay-toolkits

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 widnyana/eyay-toolkits --skill excalidraw-diagrams

Clone the repo

git clone --depth 1 https://github.com/widnyana/eyay-toolkits

Made for: Claude Code.

Or install excalidraw-diagrams, the plugin that ships this one along with the rest of its 1 skill.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/widnyana/eyay-toolkits/excalidraw-diagrams/github.svg)](https://agentmods.dev/skills/widnyana/eyay-toolkits/excalidraw-diagrams)

Your own site

<a href="https://agentmods.dev/skills/widnyana/eyay-toolkits/excalidraw-diagrams"><img src="https://agentmods.dev/badge/skills/widnyana/eyay-toolkits/excalidraw-diagrams/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/widnyana/eyay-toolkits/excalidraw-diagrams"><img src="https://agentmods.dev/badge/skills/widnyana/eyay-toolkits/excalidraw-diagrams.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 136 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,834 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00136	$0.01834
Opus 5.5	$0.00054	$0.00734
Sonnet 5.5	$0.00027	$0.00367
Haiku 4.5	$0.00014	$0.00183

Measured 8d ago against content hash 0446ed7c28fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

excalidraw-diagrams 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 8d ago.

The scan reads SKILL.md. This mod also ships 7 executable files (examples/example_frames.py, scripts/build.py, scripts/crosscheck.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

plugins/excalidraw-diagrams/skills/excalidraw-diagrams/SKILL.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Excalidraw diagrams from a source document

Generate .excalidraw scenes with a script, not by hand. The script sizes boxes from their text, binds arrows, and fails the build when the layout breaks. The diagram never holds a fact that its source document lacks.

Reference run: a 13-frame production platform diagram in an Obsidian vault, built from its design document.

Workflow

Write the goals first. One file in the scratchpad: readers, the question each frame answers, checkable success criteria, non-goals, deliverables. Template in references/design-rules.md. Get the user's go before building.
Fix the source of truth. Update the design doc first. Every value on the diagram must exist in it. A value that is not decided gets a tag: proposed, to assign, open, user-verify. Never invent an address, port, count, or version to fill space.
Write the frames. Work in a scratch directory, never inside a repo. Copy examples/example_frames.py to frames_a.py. One function per frame: f0(doc), f1(doc), and so on. Use only the helpers in scripts/xl.py (its docstring lists them).
Build. From the scratch directory: python3 <skill>/scripts/build.py frames_a,frames_b out.excalidraw. Fix every ERROR and rebuild. The build exits 1 on errors but still writes the file.
Look at every frame. <skill>/scripts/preview.sh out.excalidraw prev, then Read each PNG in prev/png. Checks do not replace looking. Fix what is cramped, empty, or wrong.
Cross-check and validate. python3 <skill>/scripts/crosscheck.py out.excalidraw source.md lists facts the source lacks. python3 <skill>/scripts/validate.py out.excalidraw checks structure. Each leftover is either added to the source or removed from the diagram.
Install. Write the file to its final path. Update the embed and the frame table in the doc so the frame names match exactly. Move the old diagram to the vault .trash/ with the reason in the filename (vault rule: never rm). Tell the user the generator ran once and later edits happen by hand in Obsidian.

Read the full file on GitHub · 86 lines

Files

What ships with it

10 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.

8d ago First seen · 86 lines · 136 tokens per session scan A 0446ed7c28fe

Subscribe to this mod's changes

excalidraw-diagrams is a skill published in the GitHub repository widnyana/eyay-toolkits (7 stars, last pushed 2d ago), licensed MIT. It adds 136 tokens to every session and 1,834 once invoked, about $0.0005 per session on Opus 5.5. 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 2026-10-08.

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