ECharts ChartPage Server

echarts-chartpage is a TypeScript toolkit that turns structured JSON data, visualization goals, and field mappings into safe, runnable HTML chart pages powered by Apache ECharts.

It ships as:

• an npm package for programmatic use
• a CLI for local automation
• an MCP server for agent workflows

The project is designed for deterministic output, controlled option generation, strong validation, and public open-source maintainability.

Features

• Generate complete single-file HTML chart pages with Apache ECharts CDN included
• Depend on the official echarts npm package in source code for types and integration correctness
• Accept structured data plus goal, theme, and field mapping input
• Recommend safe chart types from a controlled whitelist
• Build controlled ECharts options without arbitrary JS formatter injection
• Validate schema, field mappings, chart compatibility, and generated HTML basics
• Patch existing chart specs and regenerate output
• Reuse one shared core across npm API, CLI, and MCP server
• Ship with tests, CI, examples, contribution docs, and release-ready packaging

Supported Goals

• trend
• compare
• composition
• distribution
• ranking
• correlation

Supported Chart Types

• line
• bar
• stacked_bar
• pie
• donut
• scatter
• area
• table

Installation

npm install echarts-chartpage

For local development:

npm install

Quick Start

CLI

npx echarts-chartpage generate \
  --input examples/inputs/line-chart.json \
  --output revenue-trend.html

npm API

import { generateChartPage } from "echarts-chartpage";

const result = generateChartPage({
  title: "Monthly Revenue Trend",
  goal: "trend",
  theme: "light",
  outputMode: "single_html",
  data: [
    { month: "2025-01", revenue: 120 },
    { month: "2025-02", revenue: 132 },
    { month: "2025-03", revenue: 148 }
  ],
  fields: {
    x: "month",
    y: "revenue"
  }
});

console.log(result.chartType);
console.log(result.html);

MCP Server

Build first, then start the stdio server:

npm run build
npm run mcp:start

Input Model

type GenerateChartPageInput = {
  title: string;
  description?: string;
  goal: "trend" | "compare" | "composition" | "distribution" | "ranking" | "correlation";
  data: Array<Record<string, string | number | boolean | null>>;
  fields: {
    x: string;
    y: string | string[];
    series?: string;
    category?: string;
  };
  theme?: "light" | "dark";
  outputMode?: "single_html";
  chartType?: "line" | "bar" | "stacked_bar" | "pie" | "donut" | "scatter" | "area" | "table";
};

Output

generateChartPage() returns:

• normalized spec
• resolved chart type
• warnings
• controlled ECharts option or null for table fallback
• complete runnable HTML

CLI Usage

The CLI binary name is echarts-chartpage.

generate

Generate a single HTML page from JSON input:

echarts-chartpage generate \
  --input examples/inputs/line-chart.json \
  --output examples/generated/line-chart.html

recommend

Recommend a chart type:

echarts-chartpage recommend \
  --input examples/inputs/bar-chart.json

validate

Validate input and optionally validate generated HTML:

echarts-chartpage validate \
  --input examples/inputs/pie-chart.json \
  --html examples/generated/pie-chart.html

patch

Patch a base chart spec and regenerate HTML:

echarts-chartpage patch \
  --base examples/inputs/patch-base.json \
  --patch examples/inputs/patch-update.json \
  --output examples/generated/patch-example.html

MCP Usage

The server exposes these tools:

• recommend_chart_type
• generate_chart_page
• validate_chart_page
• patch_chart_page

All tool inputs and outputs are structured JSON. A typical MCP client configuration points to the built stdio server:

{
  "mcpServers": {
    "echarts-chartpage": {
      "command": "node",
      "args": ["dist/mcp/server.js"]
    }
  }
}

See examples/mcp-usage.md for request payload samples.

Programming API

Public API surface:

• generateChartPage
• recommendChartType
• validateChartInput
• validateChartPageRequest
• validateGeneratedHtml
• patchChartPage
• buildChartOption
• buildChartHtml

Runtime schemas are exported as well:

• generateChartPageInputSchema
• patchChartPageChangesSchema
• patchChartPageInputSchema
• validateChartPageInputSchema

Input / Output Example

Input:

{
  "title": "Traffic Source Mix",
  "goal": "composition",
  "theme": "light",
  "outputMode": "single_html",
  "data": [
    { "source": "Organic", "sessions": 4200 },
    { "source": "Paid", "sessions": 2100 },
    { "source": "Referral", "sessions": 1100 }
  ],
  "fields": {
    "x": "source",
    "y": "sessions",
    "category": "source"
  }
}

Output summary:

{
  "chartType": "donut",
  "warnings": [],
  "html": "<!doctype html>..."
}

Examples

The repository includes:

• examples/inputs/line-chart.json
• examples/inputs/bar-chart.json
• examples/inputs/pie-chart.json
• examples/inputs/multi-series.json
• examples/inputs/patch-base.json
• examples/inputs/patch-update.json
• examples/cli-usage.md
• examples/mcp-usage.md

Generate all example HTML files with:

npm run examples:generate

Generated HTML files are written to examples/generated/.

Agent Skill

This repository also includes a reusable Codex-style skill for agents that need to call the MCP server consistently:

• skills/echarts-chartpage-mcp/SKILL.md

It documents:

• when to trigger this MCP
• how to choose among recommend / validate / generate / patch
• structured calling rules
• few-shot examples for model prompting

Install the bundled skill into the local Codex skill directory with:

npm run build
npm run skill:install

Architecture

Project layout:

src/
  core/
    chart-recommender.ts
    option-builder.ts
    html-builder.ts
    validator.ts
    patcher.ts
    generator.ts
  cli/
    index.ts
    commands/
  mcp/
    server.ts
  schemas/
  types/
  utils/

Design rules:

• core logic is shared across all interfaces
• output is controlled and deterministic
• no arbitrary formatter functions are accepted
• only whitelisted chart types are emitted
• dataset + encode is preferred where practical

See also:

• docs/ARCHITECTURE.md
• docs/BACKGROUND.md
• docs/PUBLISHING.md
• SECURITY.md

Development Commands

npm install
npm run lint
npm run typecheck
npm run test
npm run build
npm run examples:generate

Build Command

npm run build

Outputs are emitted to dist/.

Test Command

npm run test

Publish Notes

Before publishing:

1. Update repository URLs in package.json.
2. Ensure the npm account daqiang901003 is authenticated on the publishing machine.
3. Review the CHANGELOG.md.
4. Run npm run verify.
5. Publish with npm publish.

The package is configured with:

• exports
• generated .d.ts
• bin
• files
• ESM-first output with CommonJS compatibility

Roadmap

• richer ranking-specific sorting controls
• dashboard-oriented multi-panel HTML templates
• more chart recommendation heuristics
• configurable design presets
• richer MCP metadata and traces

FAQ

Does this execute arbitrary user JavaScript?

No. The generator does not accept arbitrary formatter functions, script fragments, or custom JS injection.

Why does some input fall back to table?

The builder uses a conservative whitelist. If mappings or data types are incompatible with a controlled chart output, it falls back to a stable table rendering.

Does the generated HTML need a build step?

No. It is a single HTML file intended to open directly in the browser.

Can I force a chart type?

Yes. Set chartType in the input. If the requested chart is incompatible with the data mapping, validation warnings are returned and generation can fall back to table.

Security

• no arbitrary script injection
• no arbitrary external JS injection beyond the fixed ECharts CDN
• no formatter function injection
• controlled HTML template shape
• schema validation before generation

This project is intended for trusted structured data pipelines. If you accept untrusted input from external users, validate and sanitize it at your own boundary as well.

For the full repository policy, see SECURITY.md.

ECharts Integration Note

This project uses ECharts in two places:

• source code depends on the official echarts npm package for typed option generation
• generated HTML uses the fixed Apache ECharts CDN runtime so the output file can open directly in a browser without a bundler

Contributing

See CONTRIBUTING.md.

License

MIT. See LICENSE.