Allows AI agents to render Chart.js chart configurations as chart URLs and PNG images via the chart_url and render_chart tools.
Chart.js configs in, PNG images out, by URL. Put charts where JavaScript can't run: emails, PDFs, Slack, Notion, Markdown and AI agent replies.
https://chartpng.dev/chart?c={"type":"bar","data":{"labels":["Mon","Tue","Wed"],"datasets":[{"label":"Signups","data":[12,19,7]}]}}This repository holds the open parts of ChartPNG: the JavaScript client, the MCP server and the n8n workflow templates. The rendering API runs at chartpng.dev and is not in this repository. Free images carry a small watermark; Pro removes it (pricing).
Package | Folder | What it does |
Builds signed chart URLs and fetches PNGs. No dependencies. | ||
MCP server: AI agents draw charts with |
npm install @chartpng/clientclaude mcp add chartpng -- npx -y @chartpng/mcpEach package's README has the options and the setup for other MCP clients.
Related MCP server: QuickChart MCP Server
Import any of these in n8n with Import from URL, using the link in the second column.
Template | Import URL |
Daily chart in an email |
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Google Sheets chart to Telegram |
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Postgres query to a chart in an email |
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Google Sheets rows to a chart URL |
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Weekly Stripe revenue to Slack |
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Weekly chart to Slack |
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Weekly KPI report to Slack |
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Guides for each one: https://chartpng.dev/guides/n8n
API reference: https://chartpng.dev/docs (also as Markdown: https://chartpng.dev/docs.md)
OpenAPI: https://chartpng.dev/openapi.json
Changelog: https://chartpng.dev/changelog
Questions and bugs: open an issue here or write to hola@chartpng.dev.
MIT
Get a public PNG URL for a chart. Use it when the chart goes into an email, a Slack or chat message, a PDF or a Markdown document (as ). The data travels in the URL: anyone with the URL can see the chart and its data, so for confidential data use render_chart.
Inputs: config (required), width, height, background.
Render a chart and return the PNG image itself, to look at it or save it as a file. Takes configs up to 16 KB of JSON, larger than a URL allows.
Inputs: config (required), width, height, background.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Scored across 2 tools
The two tools are clearly distinguished by output mode: chart_url returns a public link (with an explicit confidentiality caveat), while render_chart returns the PNG bytes for private/large configs. Descriptions make the selection criterion explicit, leaving little room for misselection.
Names follow different patterns: chart_url is noun_noun while render_chart is verb_noun, so the pair does not read as a predictable family. Both are still readable and domain-relevant, but there is no consistent convention.
Two tools is thin but justified for a narrowly scoped chart-image server, since each tool covers a genuinely distinct delivery mode (public URL vs inline image). It is slightly under typical range but no tool feels redundant.
The surface covers both realistic chart delivery paths (link for sharing, image for viewing/saving) and notes the size limit for URLs. Minor gaps like explicit format or size options exist, but agents can work around them.
Diagrams, badges, charts and QR codes as plain image URLs you can paste into Markdown.
Generate chart images, diagrams, barcodes, QR codes and thermal labels on demand. PNG, SVG or PDF o…
Create, inspect, manage, and render charts and data visualizations as SVG/PNG or interactive embeds.
Renders interactive Chart.js charts and dashboards inline in AI conversations. Supports bar, line, area, pie, doughnut, scatter, and radar charts with multi-chart dashboard grids.