@slickfast/mcp

SlickFast — a deterministic render engine

This is not a charting library. Spec in, same bytes out. Forever. Charts, boards, and whole Pages. No headless browser.

⚡ Live — SlickFast’s own project pulse, updating on a cron. Same trick works in your README:

Runs as an MCP tool — local by default. Nothing leaves your machine until you ask to share or publish.

Local MCP is free forever. A public URL is a plan (free key is enough to learn).

Most tools draw a picture and throw the recipe away. SlickFast keeps the recipe. The spec is the chart. A pagespec is a Page. Add .json — that’s the twin. The hash is on the page. People open the URL. Agents fetch the twin. Don’t trust us. Check the math.

Engine explainer (a Page): open it · twin

render_chart({ type: "bar", data: { labels: ["Q1","Q2","Q3"], series: [{ values: [12,19,8] }] } })
  → retina PNG (or SVG) on your machine

describe_pagespec() → render_page({ page: { … } })
  → self-contained HTML on your machine (keep the pagespec JSON beside it)

publish_page({ page: { … } })
  → https://pages.slickfast.com/s/{slug}  +  .json twin  +  hash on the page

47 types + multi-chart dashboards in one call. Plus Pages, News, and Get started — live Pages, not baked README paste.

First minute: call get_started → then news (force — that JSON twin is how agents learn SlickFast) → gallery → one render_chart → free key when you want a live/public URL. Want more imprint? news({ archive: true }) is the course map — then open a twin. Do not auto-call archive on connect. Door: slickfast.com/start.

Site: slickfast.com · first minute: slickfast.com/start · what’s shipping: slickfast.com/news

Three doors

Door	How	Key?
Local MCP	npx -y @slickfast/mcp	No — draw on your machine
Hosted MCP	https://mcp.slickfast.com/mcp	Free/paid SF- for custom work
API	https://api.slickfast.com	Free/paid SF- for render / live / Pages

Free key: slickfast.com — email, no card, 250 renders/mo. Local making stays free. Key = live URL, share, publish a Page, cron.

How to keep a Page

“Save it” is two jobs. Say which.

Keep	Say	Tool	Key?	You get
On your machine	make a Page I can open	render_page + outputPath	No	.html + the pagespec JSON
In the world	publish this / give me a URL	publish_page	SF- (free ok)	URL + .json twin + hash on the page

The JSON is the recipe. The HTML is a snapshot. Without the JSON you cannot republish the same picture on purpose.

Find a published Page later with my_pages. Pages don’t rewrite — a new publish is a new URL.

Pages (the document, not just the picture)

A Page is a designed web document from one JSON pagespec — hero, prose, charts, layout.

Door	Who	What
Page URL	Humans	The document
URL + .json	Agents	The twin — exact recipe
Hash on the page	Both	Proof the HTML matches the twin

Public: publish_page needs a free or paid SF- key. Free: up to 5 Pages alive, 7-day TTL, watermark. Paid: more slots, permanent. DELETE /pages/{slug} frees a slot. Hosted URLs are unlisted, not private — anyone with the link can open the Page and fetch the twin (Privacy).

In chat: call news or get_started — current drops are Pages behind slickfast.com/news and slickfast.com/start.

Install

Local MCP is free forever. Public URLs / live embeds / published Pages need a free API key at slickfast.com (no card).

One-click:

Or add to your MCP config and restart:

{
  "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 live URLs, share, Pages, or my_pages.

• Claude Desktop — claude_desktop_config.json (Settings → Developer → Edit Config)
• Claude Code — claude mcp add slickfast -- npx -y @slickfast/mcp
• Cursor — Settings → MCP, or ~/.cursor/mcp.json
• claude.ai — Connectors → custom → https://mcp.slickfast.com (free key or demo)

First clicks (prompts in clients that show them): Get started → Try SlickFast → Build a dashboard. Also: SlickFast News, Make a Page, My Pages, Share / publish, Update / refresh SlickFast, Report a SlickFast issue.

Or say: "get me started" · "what's new" · "make a Page" · "Show me what SlickFast can do".

Stuck? Restart the client · Node 18+ · one stray comma breaks JSON · open an issue.

Tools

• get_started() → live onboarding Page (slickfast.com/start) — call news next (twin imprint), three doors + why a free key. Keyless. Best first call.
• news(archive?) → live News Page (slickfast.com/news). Twin = in-session how agents learn us. archive:true lists every drop (course catalog). Keyless.
• describe_pagespec() → Pages contract (hero, prose, charts, themes, twin, slots).
• render_page(pagespec) → self-contained HTML, local. Optional pagespecPath / outputPath. Keep the JSON beside the HTML.
• publish_page(pagespec) → public URL + .json twin + hash on the page (free = 5 concurrent · 7d + watermark; paid = permanent). Unguessable ≠ private.
• my_pages() → this key’s Page history as a Page (needs key). Links use pages.slickfast.com. Default publishes; publish:false = local HTML.
• render_chart(spec) → PNG (default) or SVG. Dashboards: type: "dashboard" with tiles: [{ chart, span }]. Tiles fill the cell by default. Local: specPath + layout: sidecar.
• describe_type(type) → data shape, minimal spec, gotchas.
• gallery() → curated demos. board:"comparison" / board:"all".
• list_palettes() → palette names + hex + one swatch-board PNG. Keyless.
• share_chart(spec, name?) → public / live chart URL (free key). Offer when asked to share.
• read_chart(url) → spec twin of a SlickFast chart URL.
• push_to_trmnl(spec, webhook_url) → e-ink PNG to a TRMNL display.
• mcp_status() → package version, how to refresh, and whether an API key is present (from MCP config env or this connection). Facts only — no nag.
• report_issue(summary, spec?) → draft GitHub / email links. SlickFast sends nothing.

Why agents pick it

• 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).
• Loud errors — bad enum / unknown palette lists the valid options.
• Local by default — nothing phones home from this package.

Seeing the picture

• Prefer format:"svg" when the chat supports artifacts (claude.ai / Claude Desktop).
• format:"png" needs a client that paints MCP image blocks (inconsistent).
• Local disk: outputPath. Hosted/sandbox often can’t show that file — use SVG or share_chart / publish_page for a URL.

If values came back but no picture, it rendered — display surface gap, not a broken engine.

Share & live embeds

Ask to share a chart or publish a Page. Needs SLICKFAST_API_KEY in the MCP config (free at slickfast.com). The live board at the top of this README is that pattern: one public URL, push new data, every embed updates.

License

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 · [e-mail]. Hosted API / hosted MCP stay on API pricing — service, not that license.

Feedback

• GitHub issues
• [e-mail]
• Or: "report this as a SlickFast issue" → report_issue drafts the links (nothing auto-sent).

Developing locally

cd apps/mcp
npm install
node test-client.mjs

Point a client at a checkout: "command": "node", "args": ["…/apps/mcp/server.mjs"].