io.github.liminalpepe/x402-dataviz-mcp
Free MCP server: render bar/line/area charts to SVG from structured data.
Open source Open in the app JSON README (API)
About
Free MCP server: render bar/line/area charts to SVG from structured data.
Details
- Kind
- MCP servers
- Topic
- Media, design & games
- Publisher
- liminalpepe
- Origin
- official
- Category
- ferramentas
- Transport
- local
- Version
- 0.1.0
- Last push
- 2026-08-02T10:19:40Z
- Repository state
- ativo
- Language
- TypeScript
- License
- MIT
- Added
- 2026-08-29 04:00:24
- Updated
- 2026-08-29 04:00:24
- Origin id
io.github.liminalpepe/x402-dataviz-mcp
README
# x402-dataviz-mcp
A free MCP (Model Context Protocol) server that renders bar, line, and area
charts from structured data and returns clean, hand-designed SVG. No API
key, no payment, no rate limit games — just an MCP tool any MCP client can
call.
This is the **open funnel twin** of a paid, x402-gated HTTP API:
**[x402-dataviz-poc.theliminalguy.workers.dev](https://x402-dataviz-poc.theliminalguy.workers.dev)**
— `POST /chart`, $0.01 USDC on Base per call via the
[x402 payment protocol](https://x402.org), for production/high-volume or
non-MCP (plain HTTP) use. Same renderer, same output, just billed per call
instead of free-via-MCP.
## Why this exists
The [x402 Bazaar](https://x402.org) (~14,800 agent-payable APIs at time of
writing) has zero coverage in "structured data → clean chart image." This
MCP server is the free/local half of filling that gap — try it for nothing
via MCP; reach for the paid HTTP endpoint when you need it at volume or
outside an MCP client.
## What it does
One tool, `render_chart`, takes a chart type + structured data points and
returns a rendered SVG string. Rendering is hand-rolled (no headless
browser, no native binaries, no heavy charting framework) — just
string-built SVG, so it's fast with zero runtime dependency risk.
The design bar is the actual differentiator: a real categorical color
palette (validated for colorblind-safety, not eyeballed), considered
spacing, thin marks with rounded bar ends, 2px surface gaps between bars,
ringed line markers, direct end-labels, and full light/dark theme support —
not the default-blue/red/green look of a generic charting library.
## Install & run
```bash
npx x402-dataviz-mcp
```
Or add it to an MCP client config (e.g. Claude Desktop's
`claude_desktop_config.json`):
```json
{
"mcpServers": {
"dataviz": {
"command": "npx",
"args": ["-y", "x402-dataviz-mcp"]
}
}
}
```
## Tool: `render_chart`
Input:
```jsonc
{
"type": "bar" | "line" | "area",
"title": "optional string",
"theme": "light" | "dark", // defaults to "light"
"data": [
{ "x": "Q1", "values": { "Revenue": 128000, "Cost": 84000 } },
{ "x": "Q2", "values": { "Revenue": 146500, "Cost": 91200 } }
]
}
```
`values` can hold one or more named series; series colors are assigned from
a fixed, colorblind-validated order (never generated/cycled). A legend
renders automatically for 2+ series; a single series needs no legend (the
title already names it).
Output: an SVG string (as MCP tool text content) rendering the requested
chart.
## Local development
```bash
npm install
npm run dev # runs src/index.ts directly on stdio via tsx
npm run build # compiles to dist/ for the published npm package
```
## When to use the paid HTTP twin instead
Use [`POST /chart`](https://x402-dataviz-poc.theliminalguy.workers.dev/chart)
on the paid Worker instead of this MCP server when:
- You're calling from outside an MCP client (plain HTTP, any language).
- You need production/high-volume use and want to pay per call rather than
rely on a free tool being available indefinitely.
- Your agent already speaks x402 (e.g. via `x402-fetch` / `x402-axios`) and
can pay $0.01 USDC on Base per request.
Both routes call the exact same `renderChart()` function — output is
byte-for-byte identical.
## License
MIT