LabscoMCP early access ↗
aj-geddesMCP SERVER

Sailor

Turn a description into a rendered Mermaid diagram — every diagram type, four themes, an optional hand-drawn look — with the image returned inline or written to a folder you mounted.

by aj-geddes ↗Diagrams & ChartsCommunity

LABSCO SUMMARY

Validation before rendering is the useful half.

Models write Mermaid that almost parses, and a diagram that fails silently in a README is worse than no diagram. Getting the syntax checked and the image back in the same call closes that loop. Decide up front whether you want the image inline or on disk — the mounted output directory is what makes the file path route work, and it is easy to forget in the client config.

What it is

A Mermaid diagram server that both validates and renders. It ships two front ends over the same engine: a web interface for interactive work, and an MCP server so an assistant can produce the diagram, check the syntax, and hand back the picture without you opening anything.

What you get

  • validate_and_render_mermaid — check the code and render it as PNG, with return_image=true for an inline image or return_base64_text=true for something you can save
  • get_diagram to fetch a rendered diagram later by file ID, and request_mermaid_generation to have the diagram code written from a description
  • Learning by example — get_mermaid_examples by category or complexity, get_diagram_template for a starting point, get_syntax_help for one diagram type
  • Improving what exists — analyze_diagram_code for suggestions, suggest_diagram_improvements for targeted ones
  • health_check and server_status for when rendering stops working
  • Every Mermaid type: flowchart, sequence, gantt, class, state, ER, pie, mindmap, journey and timeline
  • Themes default, dark, forest and neutral; a classic or handDrawn look; transparent or white background
  • 11 prompts, each a wizard for a specific job — flowchart_wizard, sequence_diagram_wizard, er_diagram_wizard, architecture_diagram, project_timeline, mindmap_wizard, user_journey_wizard and others

Requirements

No account and no key for diagram rendering; the web interface's AI generation needs an OpenAI or Anthropic key set in backend/.env. For MCP, clone the repository and docker build -f Dockerfile.mcp-stdio -t sailor-mcp ., then run the image from your client config with a volume mount for the output directory — that mount is where rendered files land. Docker Desktop is the only prerequisite; nothing else is installed on the host. The web interface is a separate path: docker-compose up -d and open http://localhost:5000. Package sailor at 2.0.0.

Setup effort

Run a container — build the image from the repository, then point your client at it

See installation options