ChartBytes MCP server

A Model Context Protocol server that gives any MCPclient (Claude, Cursor, Claude Code, or any agent) the generate_chart tool — render achart to a static image URL via ChartBytes and getit back both inline (to see) and as a URL/markdown snippet (to embed).

Zero dependencies — pure Python stdlib. One file, runs over stdio.

Why

Charting libraries render in a browser. But an agent writing an email, a GitHub README, aNotion page, a Slack message, or a PDF report has no browser. ChartBytes returns a plain<img> / ![chart](url) that renders anywhere. This server exposes that to agents.

Install & configure

No install required — just point your MCP client at server.py:

{
  "mcpServers": {
    "chartbytes": {
      "command": "python3",
      "args": ["server.py"]
    }
  }
}

Optional: "env": { "CHARTBYTES_URL": "https://chartbytes.meridian-digital.pro" } (defaults tothe hosted endpoint).

Tool: `generate_chart`

argument	meaning	default
`data`	values — flat list `[12,19,8,24]`, series list `[[4,8,6],[2,3,4]]`, or `"1,2,3\|4,5,6"`	required
`type`	`bar` · `hbar` · `stacked` · `pie` · `donut`	`bar`
`labels`	category labels (list or comma string)	`1,2,3…`
`title`	chart title	—
`width` / `height`	size in px	`600` × `300`
`format`	`png` · `svg`	`png`
`theme`	`light` (free) · `dark` · `brand` (Pro)	`light`

The tool returns the rendered image inline (PNG) plus the URL and a markdown snippet youcan paste straight into a README, email or Notion block.

Example session

printf '%s\n' \
  '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"demo","version":"1"}}}' \
  '{"jsonrpc":"2.0","method":"notifications/initialized"}' \
  '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"generate_chart","arguments":{"type":"donut","data":[12,19,8,24],"labels":["Q1","Q2","Q3","Q4"],"title":"Revenue"}}}' \
  | python3 server.py

Pricing

The server is MIT and free. ChartBytes itself is free for 500 renders/month (light theme);Pro (one-time $9) unlocks dark/brand themes, 25k renders/month and immutable caching:https://buy.stripe.com/fZu7sNdbW1HPgNSgOrgUM05.

License

MIT. Built by Meridian Digital.

ChartBytes MCP server