A plugin that creates a self-contained HTML file containing a Mermaid diagram, chart, flowchart, architecture illustration, or other technical visualization.

Use it to produce diagrams such as flowcharts, sequence diagrams, database diagrams, state machines, timelines, and git graphs.

It gives technical information a visual form that can be opened as a standalone web page.

visualcave — Plugin for Codex and Gemini CLI by varkart

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.

Clone the repo

git clone --depth 1 https://github.com/varkart/visualcave

Made for: Codex, Gemini CLI.

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/plugins/varkart/visualcave/gemini-extension/github.svg)](https://agentmods.dev/plugins/varkart/visualcave/gemini-extension)

Your own site

<a href="https://agentmods.dev/plugins/varkart/visualcave/gemini-extension"><img src="https://agentmods.dev/badge/plugins/varkart/visualcave/gemini-extension/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/plugins/varkart/visualcave/gemini-extension"><img src="https://agentmods.dev/badge/plugins/varkart/visualcave/gemini-extension.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

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.

Security

Grade A, and why

visualcave 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 1mo ago.

The scan reads gemini-extension.json. This mod also ships 5 executable files (scripts/add-theme-selector.js, scripts/fix-init-pattern.js, scripts/inject-error-boundaries.js, …), 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.

gemini-extension.json · 7 lines

What it actually says

{
  "name": "visualcave",
  "version": "1.0.0",
  "description": "Use when the user asks to create a diagram, chart, infographic, flowchart, architecture illustration, or any technical visualization. Outputs a self-contained HTML file using Mermaid.js.",
  "contextFileName": "SKILL.md"
}

Files

What ships with it

47 files beside gemini-extension.json 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.

1mo ago First seen · 7 lines scan A 2d6e8b4b9898

Subscribe to this mod's changes

visualcave is a plugin published in the GitHub repository varkart/visualcave (2 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-09-14.

Design and UX agent-skill cursor diagram gemini-cli html

visualcave

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What ships with it

What this file has done since we first saw it

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