A deterministic render engine. Spec in, same bytes out. Forever. Charts, boards, and whole Pages. No headless browser.
↑ Engine output — one JSON spec, one image. Get this exact board on your README with the dashboard template (teal-hero layout).
Local MCP is free forever. A public URL is a plan (free key is enough to learn).
The spec is the chart. A pagespec is a Page. Add .json — that’s the twin.
The hash is on the page. Don’t trust us. Check the math.
npm (MCP): @slickfast/mcp@0.7.37
Website: slickfast.com
Get started / News: slickfast.com/start · slickfast.com/news
Bugs: GitHub Issues · feedback@slickfast.com
The dashboard below is not a screenshot. It's a SlickFast live chart: a permanent image URL whose numbers update on their own. A scheduled job pushes fresh stats; every visitor sees current data. Live Charts — embed once, update forever.
Related MCP server: Chart-Output MCP Server
A seller ops board (funnel, bullet graph, goal ring, gauge, calendar heatmap, leaderboard — demo data):
And the board that explains the engine — it times its own render into its title:
Don't take the speed or determinism claims on faith — run the benchmark on your own machine:
git clone https://github.com/SlickFast/slickfast && cd slickfast
node scripts/bench.mjsIt renders all 47 chart types, times each, runs a 10,000-chart throughput burst, and double-renders everything to verify byte-identical output. On an M1 Max: median 15µs per chart, ~140,000 renders/sec, 47/47 deterministic. Your numbers are your numbers.
One-click:
Add to your MCP client config (Claude Code, Claude Desktop, Cursor, …):
{
"mcpServers": {
"slickfast": {
"command": "npx",
"args": ["-y", "@slickfast/mcp"],
"env": { "SLICKFAST_API_KEY": "SF-…" }
}
}
}Omit env to stay local-only (draw free forever). Add a free key from slickfast.com when you want a live URL, share, or a published Page.
Then: get_started → news → gallery → one render_chart. Full tool docs: apps/mcp/README.md.
“Save it” is two jobs. On disk: render_page + keep the pagespec JSON (no key). In the world: publish_page (SF- key) → pages.slickfast.com/s/… + .json twin. The hash is on the page. Find it later with my_pages.
Deterministic — same spec, same bytes. Cacheable. Testable.
Cheap tokens — a few dozen tokens of JSON beat hundreds of matplotlib / SVG retries.
One-field edits — swap type, palette, size; re-render. No code rewrite.
Pages = shareable memory — agent output → Page → twin → hash on the page. Not stuck in chat.
No headless browser — pure in-memory SVG → PNG (and Page HTML).
47 types + tiled dashboards in one call.
Loud errors — bad enum / unknown palette lists the valid options.
Local by default — nothing phones home from the MCP package.
Path | What it is |
| The engine: pure |
| The color library: palettes, nested themes, WCAG contrast, tokens. |
| SVG → PNG rasterization (resvg). |
| The swappable font layer. |
| Scientific charts: scatter, errorbar, lineplot, barplot, survival, Bland–Altman, Q–Q, volcano — log axes and curve fits. README |
| The MCP server published as |
| The hosted HTTP API — |
| The safety net: golden checks, registry-drift check, 323-case torture suite, palette hex check. |
| Ready-made spec presets. |
cd apps/mcp && npm install && npm run build # builds dist/index.js
cd ../../packages/raster && npm install # native resvg binding (PNG)
# from the repo root — the full safety net:
node packages/render-core/generate.mjs --check # golden snapshots (all types)
node packages/sci-core/golden/generate.mjs --check # sci-core golden snapshots
node packages/sci-core/verify-stats.mjs # sci-core statistics checks
node scripts/check-surfaces.mjs # type-registry drift check
node scripts/torture.mjs # 323 empty/edge-case renders
node scripts/check-palettes.mjs # palette hex validationThe engine is pure and deterministic by contract: no IO, no Date.now(), no
Math.random() in drawing code, and nothing ships without a snapshot test.
Bug reports and feature requests are the best way to contribute — please use the
issue templates. The MCP's
built-in report_issue tool writes a ready-to-paste report for you.
Day-to-day development happens in an internal tree and releases are published here, so a PR may be ported in rather than merged directly — you'll be credited either way. For anything non-trivial, open an issue first so we can agree on the shape.
AGPL-3.0-only. Local MCP is free. Closed commercial products (embed or self-host without AGPL) need a commercial license from $99/year: slickfast.com/license.html · licensing@slickfast.com. Hosted API / hosted MCP: slickfast.com/#pricing.
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Renders interactive Chart.js charts and dashboards inline in AI conversations.
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.
Clean messy tabular data and render publication-ready PNG charts from your AI assistant.