bennu: Skill for Claude Code

.claude/skills/diagram/SKILL.md

diagram is a skill for Claude Code from Lengros/bennu. It costs 168 tokens per session (2,675 once invoked), scanned A, original, MIT.

A tool for rendering clear diagrams, schemas, architecture maps, data flows, lifecycles, workflows, and infographics from editable code.

In plain words
What is it for?
Creating architecture diagrams, data-flow maps, workflow charts, system schemas, and other structured technical visuals.
Why use it?
It helps turn complex system relationships and processes into precise visuals with readable labels and controllable styling.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: reads .claude/ paths; mentions Codex.

This is Lengros/bennu's own configuration. It tells Claude Code how to work on bennu itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything bennu configures →

Reuse

Borrowing it

Nothing to install: this file belongs to Lengros/bennu. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/Lengros/bennu/main/.claude/skills/diagram/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/Lengros/bennu

Made for: Claude Code.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/lengros/bennu/diagram/github.svg)](https://agentmods.dev/skills/lengros/bennu/diagram)
Your own site
<a href="https://agentmods.dev/skills/lengros/bennu/diagram"><img src="https://agentmods.dev/badge/skills/lengros/bennu/diagram/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

Your own site · 80×15
<a href="https://agentmods.dev/skills/lengros/bennu/diagram"><img src="https://agentmods.dev/badge/skills/lengros/bennu/diagram.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 168 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,675 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00168 $0.02675
Opus 5 $0.00084 $0.01337
Sonnet 5 $0.00034 $0.00535
Haiku 4.5 $0.00017 $0.00267

Measured 9d ago against content hash cc213b569b12, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

diagram 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 9d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (elk-template.mjs, render.sh, template.mjs), 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.

.claude/skills/diagram/SKILL.md · 177 lines

How it starts

The opening of the file, as written. The whole thing — 177 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/diagram — render diagrams from code, not from a paint model

For anything with labels, structure, or precise relationships — architecture, data flow, lifecycle, workflow, org/topology — render it from HTML/CSS (+ SVG for connectors) screenshotted by headless Chrome. You get correct text, exact colors, and a source you can re-edit and recolor in seconds. This stays the right call whenever you need exact design tokens, fully custom composition, or pixel control with no external dependency.

Raster image-gen used to be disqualified by garbled text; that changed in 2025-26 (Nano Banana Pro / Gemini 3 Pro Image now renders legible in-image text and is marketed for infographics; GPT-image is strong too — Flux is still unreliable for fine text). Use it only for soft illustrative infographics, not structured technical diagrams (still no element-level editing, no exact palette). And in THIS environment raster is UI-only, not agent-drivable: Nano Banana Pro is available via the work Gemini subscription UI, GPT-image via the ChatGPT/Codex ($20) UI — no API key here. So for raster you produce a prompt and hand it off to the user to run in the UI — that path is /illustration-prompt. See "Reach past this skill when" below.

The whole advantage is a tight visual loop: write generator → render → Read the PNG (you can see it) → fix → re-render. Lean on it.


The pipeline

  1. Write a Node generator (.mjs) that inlines icons + emits self-contained HTML. Copy template.mjs from this skill as the skeleton.
  2. Render with render.sh out.html out.png <W> <H> <bgHex>.
  3. Read the PNG, adjust, re-render. Crop by tuning window height (see Gotchas).
  4. Work in a scratch/ dir (gitignored). Keep only the final .png + its .mjs; node_modules (lucide-static ≈ 59 MB) is build-only junk — don't leave it lying around.
cd scratch && npm init -y && npm i lucide-static
node build.mjs                                   # -> build.html (icons inlined)
.claude/skills/diagram/render.sh build.html build.png 1220 900 f1f3efff

Read the full file on GitHub · 177 lines

Files

What ships with it

3 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. 9d ago First seen · 177 lines · 168 tokens per session scan A cc213b569b12

Subscribe to this mod's changes

diagram is a skill published in the GitHub repository Lengros/bennu (2 stars, last pushed 2mo ago), licensed MIT. It adds 168 tokens to every session and 2,675 once invoked, about $0.0008 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 2026-08-31.