goldenchart-mcp

An MCP server that renders GoldenChart hand-drawn charts and flowcharts as SVG. It surfaces a tool at every level of the library — vibe, calculation, primitives, charts, and orchestration/export — so an agent can render a finished chart or compose a custom diagram from scratch.

Install & build

# from the repo root, build the library the server depends on
npm install && npm run build

# then build the server
cd mcp && npm install && npm run build

Use with an MCP client

claude mcp add goldenchart -- node /absolute/path/to/GoldenChart/mcp/dist/index.js

Or add it to a client config manually:

{
  "mcpServers": {
    "goldenchart": {
      "command": "node",
      "args": ["/absolute/path/to/GoldenChart/mcp/dist/index.js"]
    }
  }
}

Tool catalog

| Level | Tools | |-------|-------| | Charts | render_bar_chart (single/grouped/stacked), render_line_chart, render_area_chart (+ stacked), render_scatter_plot, render_pie_chart, render_flowchart, render_sankey, render_treemap, render_heatmap, render_radar | | Vibe | list_vibe_presets, resolve_vibe, preview_vibe | | Calculation | compute_scale, compute_ticks, compute_line_path, compute_area_path, compute_pie, layout_tree, compute_color_scale, profile_data, transform_data, compute_regular_polygon_path, compute_star_path, compute_arc_path, compute_wedge_path, compute_arrowhead_path | | Primitives | render_rough_path, render_rough_rect, render_rough_circle, render_rough_line, render_rough_text | | Orchestration / export | compose_surface, build_flowchart_from_spec, export_svg, export_png |

The cartesian chart tools accept an annotations array (reference lines/bands, callouts, circled points) and description / ariaLabel / dataTable for accessible output.

compose_surface scenes accept these primitive node kinds: path, rect, circle, line, text, polygon, regular-polygon, star, arc, wedge, ellipse, and arrowhead. Shape angles are in degrees (0 = east, clockwise); open shapes (arc, an unfilled arrowhead) never fill.

Resources & prompts

• vibe://presets — every preset with resolved Rough.js knobs
• palette://scales — sequential/diverging color scales with sampled swatches
• schema://chart/{type} — JSON Schema for each chart's input (bar, line, area, scatter, pie, flow, sankey, treemap, heatmap, radar)
• docs://architecture — how the layers fit together
• Prompt make-me-a-chart — guided flow: pick a vibe from a mood, choose a chart for the data, render it

Develop

npm run dev        # run the server from source via tsx
npm test           # vitest (handlers, in-memory protocol round-trip)
npm run typecheck