mermaid-skill — Установка & Живое демо

Зачем использовать

Ключевые функции

Covers 10+ Mermaid diagram types
Local render via mmdc (PNG / SVG / PDF)
Automatic layout hints to avoid crossing edges
Iterates on diagrams based on feedback
Works inside your repo, diagrams committed alongside code

Живое демо

Как выглядит на практике

mermaid-skill.replay ▶ готово

0/0

Установка

Репозиторий автора · Официальная документация Claude Skills

Сценарии использования

Реальные сценарии: mermaid-skill

Draw an architecture diagram for your current project

👤 Devs writing docs, ADRs, or onboarding guides ⏱ ~20 min beginner

Когда использовать: You keep explaining your architecture in Slack and want a picture.

Поток

Describe the system

Use mermaid-skill. Draw a flowchart of our service: client → API gateway → (auth / orders / payments) → Postgres / Redis / Stripe.✓ Скопировано

→ .mmd source with meaningful node names, rendered to PNG in docs/
Add details

Add labels on each edge showing the protocol (HTTPS, gRPC, TCP) and auth type.✓ Скопировано

→ Updated source and re-render
Commit it

Commit docs/architecture.mmd and its PNG.✓ Скопировано

→ git add and commit run

Итог: A living diagram in the repo, not a stale slide in Confluence.

Подводные камни

Diagram becomes a maze of edges — Let Claude use subgraphs and direction hints; don't cram everything on one layer

Сочетать с: filesystem · git

Produce a sequence diagram while debugging

👤 Engineers tracing a cross-service bug ⏱ ~15 min beginner

Когда использовать: You're trying to understand an async interaction and English isn't cutting it.

Поток

Describe the flow

Use mermaid-skill. Sequence diagram: browser → SSR → auth service → session store → page render, with failure mode when session is stale.✓ Скопировано

→ Sequence diagram with the failure annotated
Annotate the bug

Highlight the line where the bug manifests.✓ Скопировано

→ Annotated box/note on the offending message

Итог: A picture you can paste in the bug ticket.

Generate an ERD from your actual database schema

👤 Data engineers, backend devs ⏱ ~20 min intermediate

Когда использовать: You want a visual of your schema for a design review.

Поток

Introspect

Use mermaid-skill. Read the schema.sql (or query the live DB via postgres MCP) and produce a Mermaid ERD.✓ Скопировано

→ .mmd ERD with relationships and cardinalities
Trim noise

Drop audit tables and focus on the core domain entities.✓ Скопировано

→ Trimmed ERD

Итог: An accurate ERD without manual drawing.

Подводные камни

Cardinalities wrong when inferred — Provide the actual foreign-key definitions; don't let the model guess

Сочетать с: postgres

Комбинации

Сочетайте с другими MCP — эффект x10

mermaid-skill + filesystem

Keep diagrams alongside the code they describe

For every service in services/, add a docs/architecture.mmd and render it.✓ Скопировано

mermaid-skill + postgres

Auto-generate ERDs from live databases

Connect to the staging DB and render its schema as a Mermaid ERD.✓ Скопировано

mermaid-skill + git

Diagram stays versioned with code changes

Commit updated diagrams in the same PR as the code changes they describe.✓ Скопировано

Инструменты

Что предоставляет этот MCP

Инструмент	Входные данные	Когда вызывать	Стоимость
write_mermaid	description, diagram type	Any diagram request	0
render_mmdc	.mmd path, output format	After source is final	local mmdc
iterate_diagram	current diagram + feedback	Reviewer feedback	0

Стоимость и лимиты

Во что обходится

Квота API: None
Токенов на вызов: Small — Mermaid source is compact
Деньги: Free (mmdc is open source)
Совет: For big diagrams, generate subgraphs separately to avoid retrying large rewrites.

Безопасность

Права, секреты, радиус поражения

Хранение учётных данных: None

Исходящий трафик: None from skill itself

Устранение неполадок

Частые ошибки и исправления

mmdc not found

Install globally: npm i -g @mermaid-js/mermaid-cli

Проверить: which mmdc

Render fails with syntax error

Mermaid has version-specific syntax; run mmdc --version and match the skill's assumed version

Проверить: mmdc --version

Diagram is a mess of crossing edges

Add direction hints (TD/LR), group with subgraphs, or split into multiple diagrams

Альтернативы

mermaid-skill в сравнении

Альтернатива	Когда использовать	Компромисс
PlantUML / draw.io	You need more control or non-Mermaid syntax	More setup, different rendering toolchain
paperbanana-skill	Academic publication-quality diagrams	Heavier; different aesthetic goals

Ещё

Ресурсы

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