mermaid-visualizer

mermaid-visualizer is a skill for Claude Code from closedloop-ai/claude-plugins. It costs 55 tokens per session (442 once invoked), scanned A, original, Apache-2.0.

A guide for creating Mermaid diagrams, which are text-based diagrams used to show flows, relationships, and system structure. It covers diagrams such as flowcharts, sequence diagrams, state diagrams, and database relationship diagrams.

In plain words
What is it for?
Use it to create diagrams of control flows, system architectures, data flows, state changes, sequences, classes, or database relationships.
Why use it?
Complex systems can be difficult to understand from prose alone. A diagram can make steps, components, data movement, and relationships easier to inspect.

Skill for Claude Code

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

Part of the platform plugin — 3 skills shipped together

Good fit Use it to create diagrams of control flows, system architectures, data flows, state changes, sequences, classes, or database relationships.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/closedloop-ai/claude-plugins/mermaid-visualizer
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 closedloop-ai/claude-plugins --skill mermaid-visualizer
Clone the repo
git clone --depth 1 https://github.com/closedloop-ai/claude-plugins

Made for: Claude Code.

Or install platform, the plugin that ships this one along with the rest of its 3 skills.

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 mermaid-visualizer

README.md
[![agentmods](https://agentmods.dev/badge/skills/closedloop-ai/claude-plugins/mermaid-visualizer.svg)](https://agentmods.dev/skills/closedloop-ai/claude-plugins/mermaid-visualizer)
Your own site
<a href="https://agentmods.dev/skills/closedloop-ai/claude-plugins/mermaid-visualizer"><img src="https://agentmods.dev/badge/skills/closedloop-ai/claude-plugins/mermaid-visualizer.svg" alt="Measured on agentmods" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 442 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 $0.00055 $0.00442
Opus 5 $0.00028 $0.00221
Sonnet 5 $0.00011 $0.00088
Haiku 4.5 $0.00006 $0.00044

Measured yesterday against content hash f58563602210, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

mermaid-visualizer 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 yesterday.

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/platform/skills/mermaid-visualizer/SKILL.md · 39 lines

What it actually says

Mermaid Visualizer

Purpose

To create clear, effective Mermaid diagrams that visualize complex concepts, system architectures, and control flows. This skill provides comprehensive guidance for generating diagrams that aid understanding of intricate systems and processes.

How to Use This Skill

  1. Understand the concept being visualized by reviewing the user's description
  2. Select the appropriate diagram type from the diagram type options below
  3. Reference the Mermaid syntax guide in references/mermaid-syntax.md for correct syntax
  4. Create the diagram using Mermaid markdown syntax
  5. Embed the diagram in the response using markdown code fence with mermaid language identifier
  6. Follow best practices from references/mermaid-syntax.md to ensure clarity and correctness

Diagram Types Supported

  • Flowcharts: Decision trees, process flows, control flows
  • Sequence Diagrams: Interactions between components or systems over time
  • State Diagrams: State transitions and triggers
  • Class Diagrams: Object-oriented relationships and hierarchies
  • Entity Relationship Diagrams: Database schemas and data relationships
  • System Architecture Diagrams: Component relationships and service interactions

Key Mermaid Concepts

Node Syntax: Use NodeID[Label] for rectangular nodes, {Decision} for diamonds, (Rounded) for rounded nodes.

Edge Syntax: Connect nodes with --> for arrows, -.-> for dotted lines, and |Label| for edge descriptions.

Prohibited Symbols: Avoid unescaped quotes, pipes, brackets, colons, and semicolons in node IDs. Use underscores or hyphens for spaces in IDs, and quoted strings for complex labels.

For detailed syntax guidance, refer to references/mermaid-syntax.md.

Files

What ships with it

1 file 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. yesterday First seen · 39 lines · 55 tokens per session scan A f58563602210

Subscribe to this mod's changes

mermaid-visualizer is a skill published in the GitHub repository closedloop-ai/claude-plugins (103 stars, last pushed yesterday), licensed Apache-2.0. It adds 55 tokens to every session and 442 once invoked, about $0.0003 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 2026-09-07.

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