Semiotic

A React data visualization library designed for AI-assisted development.

Simple charts in 5 lines. Network graphs, streaming data, and coordinated dashboards when you need them. Structured schemas and an MCP server so AI coding assistants generate correct chart code on the first try.

What's New in 3.9.2

3.9.2 expands Semiotic's portable chart, accessibility, evidence, and rendering surfaces while tightening browser/server parity and production entry graphs:

• LineChart gains the dedicated semiotic/line entry, and chart HOCs, network layouts, force workers, and optional overlays load only the runtime code their chart paths need.
• ChartAccessContract@1, ChartEvidenceEnvelope@1, and the new semiotic/access and semiotic/evidence entries provide schema-backed access inventories, privacy-aware provenance, deterministic hashing, MCP evidence fragments, and publication gates.
• ParallelCoordinatesRecipe and CalendarHeatmapRecipe are now portable, JSON-safe chart recipes, while Minimap, ScatterplotMatrix, and ChainReaction gain evidence-backed static rendering through semiotic/server and MCP.
• Typed realtime handles preserve authored row types, styleRules now spans ordinal, XY, network, geo, realtime, and physics families, and structured navigation provides overview-first hierarchy and choropleth semantics.
• Renderer and interaction fixes cover constant-value heatmaps, linked selection and hover, automatic network legends, Waterfall and Radar geometry, marginal graphics, custom layouts, tree-shaken network registration, and instance-local accessible names.
• Release evidence now includes controlled dense-browser measurements, deterministic linked-hover cohorts, generated bundle guidance, stronger AI diagnostics, and stricter shipped-product and contributor gates.

Why Semiotic

Semiotic is a data visualization library for React that combines broad chart coverage with first-class AI tooling. It handles the chart types that most libraries skip — network graphs, streaming data, statistical distributions, coordinated views — and ships with machine-readable schemas so LLMs can generate correct code without examples.

Built for AI-assisted development

Semiotic ships with everything an AI coding assistant needs to generate correct visualizations without trial and error:

• semiotic/ai — a single import with the schema-backed chart capability catalog (XY, ordinal, network, realtime, geo, value, and portable recipes), optimized for LLM code generation. See ai/surface-manifest.json for the generated current inventory. Note: the published entry files are pre-bundled, so importing one chart from semiotic/ai still ships most of the bundle — treat it as a codegen/tooling surface and use family subpaths (semiotic/xy, semiotic/geo, semiotic/value, …) in production code, at roughly half the single-chart cost.
• ai/schema.json — machine-readable prop schemas for every component
• npx semiotic-mcp — an MCP server for tool-based chart rendering in any MCP client
• npx semiotic-ai --doctor — validate component + props JSON from the command line with typo suggestions and anti-pattern detection
• diagnoseConfig(component, props) — programmatic anti-pattern detector with actionable fixes, spanning validation, encoding, accessibility, and misleading-design (deception) checks
• auditData(component, props, data?) — chart-aware numeric preflight for inputs that pass schema validation but break the math: non-finite values, zero-span domains, invalid log inputs, negative size geometry, unsafe normalized totals, and scale-dominating outliers. Returns bounded row evidence and flows into diagnoseConfig, Chart Clinic, CLI doctor, and opt-in ChartContainer notifications
• AGENTS.md — concise repository workflow shared by modern coding agents; CLAUDE.md imports it and Copilot receives a short compatibility bridge
• ai/reference.md — complete on-demand product reference, kept out of always-loaded coding-agent context
• llms.txt — machine-readable documentation following the emerging standard

Every chart includes a built-in error boundary, dev-mode validation warnings with typo suggestions, and accessibility features (canvas aria-label, keyboard-navigable legends, aria-live tooltips, SVG <title>/<desc>) so AI-generated code fails gracefully with actionable diagnostics instead of a blank screen.

Accessibility is a release surface

The European Accessibility Act has applied to covered products and services since 28 June 2025. A chart library cannot certify an application's legal compliance: scope, content, surrounding controls, testing, and national enforcement remain the application owner's responsibility. Semiotic supplies testable infrastructure for that work: keyboard interaction, accessible data tables, layered descriptions, structured navigation, reduced-motion and forced-colors paths, and WCAG-derived contrast tests for shipped theme presets. See the Accessibility docs and run the application's own assistive-technology and user testing.

Beyond standard charts

Network visualization. Force-directed graphs, Sankey diagrams, chord diagrams, tree layouts, treemaps, circle packing, and orbit diagrams — all as React components with the same prop API as LineChart.

Streaming data. Realtime charts render on canvas at 60fps with a ref-based push API. Rapid network edge pushes coalesce into one layout per animation frame, while read/mutation methods preserve synchronous read-after-write semantics. Built-in decay, pulse, and staleness encoding for monitoring dashboards.

Coordinated views. LinkedCharts provides hover cross-highlighting, brush cross-filtering, coordinate-based linked crosshairs, and selection synchronization across any combination of chart types through shared selection state.

Geographic visualization. Choropleth maps, proportional symbol maps, flow maps with animated particles, and distance cartograms — all canvas-rendered with d3-geo projections, zoom/pan, tile basemaps, and drag-rotate globe spinning.

Statistical summaries. Box plots, violin plots, swarm plots, histograms, LOESS smoothing, forecast with confidence envelopes, and anomaly detection. Marginal distribution graphics on scatterplot axes with a single prop.

First-class annotations. Annotations are data-bound objects, not post-hoc artwork. Labels, callouts, thresholds, enclosures, statistical overlays, and React widgets move with the chart and render through browser, SSR, and export paths. Opt into placement, hierarchy, density, progressive disclosure, audience-aware amount, provenance, and editorial lifecycle when the chart needs to communicate more than its encoding alone.

Choose the API layer

Layer	For	Example
Charts	Common chart forms with chart-level props	<LineChart data={d} xAccessor="x" yAccessor="y" />
Frames	Full control over rendering, interaction, and layout	<StreamXYFrame chartType="line" lineStyle={...} />

Chart HOCs register only the mark plugins they need. Direct StreamXYFrame loads the remaining built-ins on first client paint. Call registerBuiltInXYPlugins() from semiotic/xy or semiotic/realtime/core before the first render when SSR or the first frame must include marks.

Every Chart component accepts a frameProps prop to access the underlying Frame API without leaving the simpler interface.

Serialization and interop

Charts serialize to JSON and back: toConfig, fromConfig, toURL, copyConfig, configToJSX. Have Vega-Lite specs? fromVegaLite(spec) translates them to Semiotic configs — works with configToJSX() for full round-trip from notebooks and AI-generated specs.

Need an external pitfall review? The experimental unstable_toDataPitfallsChain() builds a dependency-free chain input for datapitfalls, combining the Semiotic config, JSX, reader grounding, diagnostics, accessibility audit, and optional rendered SVG/image evidence:

import { unstable_toDataPitfallsChain } from "semiotic/experimental"
import { detectPitfalls } from "datapitfalls"

const input = unstable_toDataPitfallsChain("LineChart", props, {
  narrative: "Monthly sales are accelerating.",
  rendered: { svg, evidence },
})

const report = await detectPitfalls(input, { apiKey: process.env.ANTHROPIC_API_KEY })

The return path stays dependency-free too. Use whole-chart findings as ChartContainer notifications, and only turn findings into annotations after your app can anchor them to marks or semantic positions:

import { ChartContainer } from "semiotic"
import { LineChart } from "semiotic/xy"
import {
  unstable_toDataPitfallsAnnotations,
  unstable_toDataPitfallsNotifications,
} from "semiotic/experimental"

const notifications = unstable_toDataPitfallsNotifications(report)
const annotations = unstable_toDataPitfallsAnnotations(report, {
  anchorFor: (finding) =>
    finding.ruleId === "truncated-axis" ? { x: 9, y: 9000 } : null,
})

<ChartContainer notifications={notifications}>
  <LineChart {...props} annotations={annotations} />
</ChartContainer>

When to use something else

Need a standard bar or line chart for a dashboard you'll never need to customize beyond colors and labels? Recharts has a larger ecosystem and more community examples. Need GPU-accelerated rendering for millions of data points? Apache ECharts handles that scale.

Semiotic is for projects that outgrow those libraries — when you need network graphs alongside time series, streaming data alongside static snapshots, or coordinated views across chart types.

Install

npm install semiotic

Requires React 18.1+ or React 19.

Quick Examples

Coordinated Dashboard

Hover one chart and highlight the same data in another through a shared selection:

import { LinkedCharts, Scatterplot, BarChart } from "semiotic"

<LinkedCharts>
  <Scatterplot
    data={data} xAccessor="age" yAccessor="income" colorBy="region"
    linkedHover={{ name: "hl", fields: ["region"] }}
    selection={{ name: "hl" }}
  />
  <BarChart
    data={summary} categoryAccessor="region" valueAccessor="total"
    selection={{ name: "hl" }}
  />
</LinkedCharts>

Streaming Metrics with Decay

Live data fades old points, flashes new ones, flags stale feeds:

import { RealtimeLineChart } from "semiotic"

const chartRef = useRef()
chartRef.current.push({ time: Date.now(), value: cpuLoad })

<RealtimeLineChart
  ref={chartRef}
  timeAccessor="time"
  valueAccessor="value"
  decay={{ type: "exponential", halfLife: 100 }}
  staleness={{ threshold: 5000, showBadge: true }}
/>

Network Graphs

Force-directed graphs and Sankey diagrams — same API as LineChart:

import { ForceDirectedGraph, SankeyDiagram } from "semiotic"

<ForceDirectedGraph
  nodes={people} edges={friendships}
  colorBy="team" nodeSize={8} showLabels
/>

<SankeyDiagram
  edges={budgetFlows}
  sourceAccessor="from" targetAccessor="to" valueAccessor="amount"
/>

Geographic Visualization

Choropleth maps, flow maps, and distance cartograms with canvas rendering, zoom/pan, tile basemaps, and animated particles:

import { ChoroplethMap, FlowMap, DistanceCartogram } from "semiotic/geo"

<ChoroplethMap
  areas={geoJsonFeatures} valueAccessor="gdp"
  colorScheme="viridis" projection="equalEarth" zoomable tooltip
/>

<FlowMap
  nodes={airports} flows={routes} valueAccessor="passengers"
  showParticles particleStyle={{ color: "source", speedMultiplier: 1.5 }}
/>

<DistanceCartogram
  points={cities} center="rome" costAccessor="travelDays"
  showRings costLabel="days" lines={routes}
/>

Streaming System Monitor

Live service topology with threshold alerting and click-to-inspect:

import { StreamNetworkFrame, ChartContainer, DetailsPanel, LinkedCharts } from "semiotic"

const chartRef = useRef()
chartRef.current.push({ source: "API", target: "Orders", value: 15 })

<LinkedCharts>
  <ChartContainer title="System Monitor" status="live"
    detailsPanel={
      <DetailsPanel position="right" trigger="click">
        {(datum) => <div>{datum.id}: {datum.value} req/s</div>}
      </DetailsPanel>
    }>
    <StreamNetworkFrame ref={chartRef} chartType="sankey"
      showParticles particleStyle={{ proportionalSpeed: true }}
      thresholds={{ metric: n => n.value, warning: 100, critical: 250 }}
    />
  </ChartContainer>
</LinkedCharts>

Standard Charts

Line, bar, scatter, and area charts share the same accessor-driven API:

import { LineChart, BarChart } from "semiotic"

<LineChart
  data={salesData}
  xAccessor="month" yAccessor="revenue"
  curve="monotoneX" showPoints
/>

<BarChart
  data={categoryData}
  categoryAccessor="department" valueAccessor="sales"
  orientation="horizontal" colorBy="region"
/>

All Chart Components

Category	Components
XY	LineChart AreaChart DifferenceChart StackedAreaChart Scatterplot ConnectedScatterplot BubbleChart Heatmap QuadrantChart MultiAxisLineChart MinimapChart CandlestickChart ScatterplotMatrix
Categorical	BarChart StackedBarChart GroupedBarChart LikertChart SwimlaneChart FunnelChart SwarmPlot BoxPlot Histogram ViolinPlot RidgelinePlot DotPlot PieChart DonutChart GaugeChart
Network	ForceDirectedGraph ChordDiagram SankeyDiagram ProcessSankey TreeDiagram Treemap CirclePack OrbitDiagram
Geo	ChoroplethMap ProportionalSymbolMap FlowMap DistanceCartogram
Realtime	RealtimeLineChart RealtimeHistogram RealtimeSwarmChart RealtimeWaterfallChart RealtimeHeatmap
Coordination	LinkedCharts
Layout	ChartGrid ContextLayout CategoryColorProvider
Frames	StreamXYFrame StreamOrdinalFrame StreamNetworkFrame StreamGeoFrame

Vega-Lite Translation

Paste a Vega-Lite spec, get a Semiotic chart:

import { fromVegaLite } from "semiotic/data"
import { configToJSX, fromConfig } from "semiotic"

const config = fromVegaLite({
  mark: "bar",
  data: { values: [{ a: "A", b: 28 }, { a: "B", b: 55 }] },
  encoding: {
    x: { field: "a", type: "nominal" },
    y: { field: "b", type: "quantitative" },
  },
})

// Render directly
const { componentName, props } = fromConfig(config)
// → componentName: "BarChart", props: { data, categoryAccessor: "a", valueAccessor: "b" }

// Or generate JSX code
configToJSX(config)
// → <BarChart data={[...]} categoryAccessor="a" valueAccessor="b" />

Supports bar, line, area, point, rect, arc, tick marks with encoding translation for color, size, aggregation, and binning.

Conversation Arc Telemetry

Capture and replay the path an AI-assisted chart session took:

import {
  createLocalStorageConversationArcSink,
  enableConversationArc,
  getConversationArcStore,
  loadConversationArc,
  registerConversationArcSink,
} from "semiotic/ai"

const sink = createLocalStorageConversationArcSink({ key: "my-app:arc" })
registerConversationArcSink(sink)
enableConversationArc({ sessionId: "session-abc" })

getConversationArcStore().record({ type: "chart-rendered", component: "LineChart" })
loadConversationArc(sink.load(), { enabled: false })

Bundle Sizes

Semiotic ships 32 stable JavaScript entry points (31 subpaths plus the root). Don't import from "semiotic" unless you need everything — use the smallest sub-path that matches your charts or tooling.

The numbers below are first-party artifact cost: the gzip size of Semiotic's own code for each sub-path. They exclude React and other runtime dependencies, so they are not a prediction of a cold application bundle. Do not add artifact rows to estimate an app: dependency resolution and cross-import deduplication happen in the consumer bundler and are measured separately below.

Entry Point	gzip	What's inside
semiotic/access	35 KB	Chart Access Contract factory and first-wave baseline contracts
semiotic/evidence	50 KB	Chart Evidence Envelope, deterministic hashing, and publication gate
semiotic/line	135 KB	LineChart only — one-chart micro boundary
semiotic/xy	166 KB	LineChart, AreaChart, Scatterplot, Heatmap, + 8 more XY charts
semiotic/ordinal	130 KB	BarChart, PieChart, BoxPlot, Histogram, + 11 more categorical charts
semiotic/network	157 KB	ForceDirectedGraph, SankeyDiagram, ProcessSankey, Treemap, + 4 more
semiotic/geo	113 KB	ChoroplethMap, FlowMap, DistanceCartogram, ProportionalSymbolMap
semiotic/realtime	162 KB	RealtimeLineChart, RealtimeHistogram, + 4 streaming charts
semiotic/realtime/core	161 KB	Streaming chart types, HOCs, and buffer helpers
semiotic/realtime/react	1 KB	Stream status and synced push hooks
semiotic/server	216 KB	renderChart, renderDashboard, renderToImage, renderToAnimatedGif
semiotic/server/node	216 KB	renderChart, renderDashboard, renderToImage, renderToAnimatedGif
semiotic/server/edge	222 KB	renderChart, renderChartWithEvidence, renderToStaticSVG, renderDashboard
semiotic/utils	103 KB	ThemeProvider, numeric/accessibility audits, serialization — no chart components
semiotic/utils/core	95 KB	Pure theme helpers, numeric/accessibility audits, and serialization
semiotic/utils/react	7 KB	ThemeProvider, useTheme, useReducedMotion, useHighContrast, useStreamStatus
semiotic/recipes	100 KB	Pure layout functions (waffle, marimekko, flextree, dagre, …)
semiotic/recipes/core	92 KB	Pure layout functions (waffle, marimekko, flextree, dagre, …)
semiotic/recipes/react	8 KB	Glyph and React layout-selection helpers
semiotic/themes	12 KB	Theme presets only (tufte, carbon, etc.)
semiotic/themes/core	12 KB	Theme presets and token helpers
semiotic/themes/react	7 KB	ThemeProvider/useTheme and hooks
semiotic/data	4 KB	bin, rollup, groupBy, pivot, fromVegaLite
semiotic/value	6 KB	BigNumber — focal-value KPI / scorecard (SingleValueFrame POC)
semiotic/physics	168 KB	GaltonBoardChart, EventDropChart, UnitPileChart, CollisionSwarmChart, PacketFlowChart, PhysicsCustomChart
semiotic/physics/matter	1 KB	Matter.js migration helpers + optional peer guard (no chart components)
semiotic/physics/rapier	1 KB	Rapier peer guard + adapter decision metadata (no chart components)
semiotic/ai	553 KB	All schema-backed charts + validation — optimized for LLM code generation
semiotic/ai/core	101 KB	suggestCharts, auditData, describeChart, repairChartConfig, tool adapters — no chart components
semiotic/controls	11 KB	DirectManipulationControl, CircularBrush, MobileStandardControls, auditVisualizationControls — no frame renderer
semiotic/rough	3 KB	Optional deterministic Rough.js paint backend — exact Semiotic geometry remains authoritative
semiotic	360 KB	Everything below (full bundle)

Cold-consumer named imports

The table above is first-party artifact cost, not an application bundle. The generated table below measures a different thing: a fresh consumer bundles one retained named import from a packed semiotic tarball through the public export path. It includes Semiotic and its resolved runtime dependencies, but externalizes React/React DOM and optional adapter peers that the host application owns. Each row starts cold, so use it to compare one public import choice—not to add together an application's rows. The checked machine-readable baseline is benchmarks/setup/cold-consumer-imports.json; refresh it after a production build with npm run docs:cold-consumer.

Method: fresh npm pack --ignore-scripts tarball → temporary consumer → minified/tree-shaken esbuild ESM bundle → gzip -9. React/React DOM and optional adapter peers are external; Semiotic and its resolved runtime dependencies are included.

Public named import	Runtime	gzip cold-consumer bundle
import { LineChart } from "semiotic"	browser	140.0 KiB
import { LineChart } from "semiotic/xy"	browser	140.4 KiB
import { LineChart } from "semiotic/line"	browser	140.3 KiB
import { BarChart } from "semiotic/ordinal"	browser	133.1 KiB
import { SankeyDiagram } from "semiotic/network"	browser	157.5 KiB
import { RealtimeLineChart } from "semiotic/realtime"	browser	141.0 KiB
import { RingBuffer } from "semiotic/realtime/core"	browser	0.7 KiB
import { useStreamStatus } from "semiotic/realtime/react"	browser	0.6 KiB
import { GaltonBoardChart } from "semiotic/physics"	browser	150.3 KiB
import { MATTER_PHYSICS_CAPABILITIES } from "semiotic/physics/matter"	browser	0.2 KiB
import { RAPIER_PHYSICS_CAPABILITIES } from "semiotic/physics/rapier"	browser	0.2 KiB
import { renderChart } from "semiotic/server"	node	263.4 KiB
import { generateFrameSVGs } from "semiotic/server/edge"	node	118.8 KiB
import { renderToImage } from "semiotic/server/node"	node	264.0 KiB
import { suggestCharts } from "semiotic/ai"	browser	253.5 KiB
import { suggestCharts } from "semiotic/ai/core"	browser	44.8 KiB
import { createChartAccessContract } from "semiotic/access"	browser	31.0 KiB
import { toEvidenceEnvelope } from "semiotic/evidence"	browser	40.1 KiB
import { bin } from "semiotic/data"	browser	0.4 KiB
import { ChoroplethMap } from "semiotic/geo"	browser	115.5 KiB
import { createRoughRenderMode } from "semiotic/rough"	browser	3.1 KiB
import { resolveThemePreset } from "semiotic/themes"	browser	2.6 KiB
import { resolveThemePreset } from "semiotic/themes/core"	browser	2.6 KiB
import { ThemeProvider } from "semiotic/themes/react"	browser	5.2 KiB
import { validateProps } from "semiotic/utils"	browser	9.2 KiB
import { smartTickFormat } from "semiotic/utils/core"	browser	6.9 KiB
import { useReducedMotion } from "semiotic/utils/react"	browser	2.4 KiB
import { waffleLayout } from "semiotic/recipes"	browser	1.7 KiB
import { waffleLayout } from "semiotic/recipes/core"	browser	1.7 KiB
import { Glyph } from "semiotic/recipes/react"	browser	0.8 KiB
import { BigNumber } from "semiotic/value"	browser	5.9 KiB
import { DirectManipulationControl } from "semiotic/controls"	browser	1.3 KiB

Line-boundary interpretation: the retained named import from semiotic/line emits 422.7 KiB raw versus 422.7 KiB from semiotic/xy; gzip differs by 0.1 KiB (0.1%). Tree-shaking converges both paths on the same LineChart implementation graph. Treat semiotic/line as a narrower API/direct-ESM artifact boundary, not an application-bundle saving. Do not add another per-chart entry until its packed named import beats the family path by both 10 KiB gzip and 7%.

d3 packaging model: Semiotic externalizes the twelve d3 modules it imports and declares them as normal runtime dependencies. Consumers do not need to install d3 packages manually; their bundler resolves, deduplicates, and tree-shakes that dependency graph. A packed webpack comparison favored this model in three of four representative chart families, and a Next 16 webpack route was 21.8 KiB gzip smaller than the fully bundled alternative. The one bundled win, Sankey, was only 1.1 KiB gzip. This choice retains a 22-package, 1.9 MB unpacked d3 install closure in exchange for smaller common application graphs and an ordinary dependency contract. The checked policy is npm run check:d3-packaging; the reproducible evidence is in benchmarks/setup/d3-packaging.json and can be regenerated with npm run measure:d3-packaging -- --toolchain-root <dir> after installing webpack and Next in that isolated toolchain directory.

// Import from the sub-path, not from "semiotic"
import { LineChart } from "semiotic/xy"
import { BarChart } from "semiotic/ordinal"
import { SankeyDiagram } from "semiotic/network"
import { ChoroplethMap } from "semiotic/geo"

Tree-shaking & multi-subpath imports: Family entries (semiotic/xy, semiotic/network, semiotic/ai, …) are built as one ESM graph with shared chunks. Stream frames, renderers, and other common code ship once and are imported by every entry that needs them — so combining semiotic/ai + semiotic/xy + semiotic/network does not mean paying for three full copies of the runtime. The package is marked "sideEffects": false, so modern bundlers keep only the named exports you retain (e.g. LineChart + suggestCharts). Prefer family subpaths for clarity; import AI helpers from semiotic/ai or the lighter semiotic/ai/core when you do not need the chart catalog.

When to use "semiotic": Fine when you want one import for mixed families. Shared chunks prevent duplicated runtime code across family subpaths; the cold-consumer table above is the better guide for a single named import.

CommonJS compatibility note: require("semiotic/xy") loads the shared CommonJS client bundle (about 2.1 MB before compression) so React contexts stay singletons across family imports. Prefer ESM imports in browser builds when bundle size matters; splitting that CJS client without a context-identity contract would be unsafe.

TypeScript

Built with strict: true. Full type definitions ship with the package. Generics for type-safe accessors:

interface Sale { month: number; revenue: number }

<LineChart<Sale>
  data={sales}
  xAccessor="month"    // TS validates this is keyof Sale
  yAccessor="revenue"
/>

Server-Side Rendering

All chart components render SVG automatically in server environments — no special imports or configuration needed. Non-streaming chart HOCs can be imported and rendered directly from a Next.js Server Component: Semiotic's "use client" directive defines the package boundary, so the importing page does not need its own wrapper or directive. Props crossing that boundary must remain serializable; add an app-owned client wrapper only when you introduce hooks, callback props, browser state, or a push-driven streaming chart.

// app/dashboard/page.tsx — a Next.js Server Component
import { LineChart } from "semiotic/xy"

// Server: renders <svg> with path/circle/rect elements
// Client: renders <canvas> with SVG overlay for axes
export default async function DashboardPage() {
  const data = await fetchMetrics()
  return <LineChart data={data} xAccessor="date" yAccessor="value" />
}

For standalone SVG/PNG/GIF generation (email, OG images, PDF, Slack), use the server entry point:

import { renderChart, renderToImage, renderToAnimatedGif } from "semiotic/server"

// SVG — sync, no dependencies
const svg = renderChart("LineChart", {
  data, xAccessor: "date", yAccessor: "value",
  theme: "tufte", title: "Revenue Trend",
})

// PNG — async, requires sharp
const png = await renderToImage("BarChart", { data, ... }, { format: "png", scale: 2 })

// Animated GIF — async, requires sharp + gifenc
const gif = await renderToAnimatedGif("line", data, { ... }, { fps: 12 })

MCP Server

mcp-name: io.github.nteract/semiotic

Semiotic ships with an MCP server that lets AI coding assistants render charts, diagnose configuration problems, discover schemas, read packaged AI guidance, and get chart recommendations via tool calls.

Setup

Add to your MCP client config (e.g. claude_desktop_config.json for Claude Desktop):

{
  "mcpServers": {
    "semiotic": {
      "command": "npx",
      "args": ["semiotic-mcp"]
    }
  }
}

No API keys or authentication required. The server runs locally via stdio. HTTP mode is also available for inspectors, web clients, and ChatGPT Apps SDK experiments: npx semiotic-mcp --http --port 3001. It binds to 127.0.0.1 by default; intentionally expose another interface with --host 0.0.0.0 or MCP_HOST=0.0.0.0. Since 3.7.2, HTTP mode is stateless: each request gets a fresh read-only MCP server + transport, so it can autoscale on serverless hosts without sticky sessions.

For ChatGPT developer mode, expose the HTTP endpoint over HTTPS with a tunnel and create a connector that points at https://<your-tunnel>/mcp. The experimental Apps SDK surface is renderInteractiveChart, which returns a text/html;profile=mcp-app widget template plus a hidden SVG payload rendered by Semiotic on the MCP server.

For a hosted deployment, see deploy/cloud-run. The wrapper runs the published semiotic-mcp binary, exposes /mcp plus health endpoints, and supports MCP_ALLOWED_HOSTS for production host-header allowlisting. For ChatGPT Apps domain verification, set OPENAI_APPS_CHALLENGE_TOKEN so HTTP mode serves the raw token from /.well-known/openai-apps-challenge.

Tools

Tool	Description
renderChart	Render a Semiotic chart to static SVG. Supports the components returned by getSchema that are marked [renderable]. Pass { component: "LineChart", props: { data: [...], xAccessor: "x", yAccessor: "y" } }. Returns SVG string plus a "Render evidence" JSON block (mark counts by scene type, resolved axis domains, empty flag, annotation count, accessible name) so agents can verify the chart drew data marks, or validation errors with fix suggestions.
renderInteractiveChart	Render a static-data chart as a ChatGPT Apps widget. Uses the same Semiotic server render path as renderChart, then hydrates an iframe UI with fit, zoom, data, hover, and render-evidence controls.
getSchema	Return the prop schema for a specific component. Pass { component: "LineChart" } to get its props, or omit component to list the complete schema-backed catalog. Components marked [renderable] are available through renderChart; realtime charts require a browser/live environment.
suggestChart	Sample-row recommender. Pass { data: [{...}, ...] } with 1–5 sample objects plus optional broad intent/capability filters.
suggestCharts	Capability-based recommender for bounded row data. Returns ranked chart suggestions with scores, reasons, caveats, import paths, and ready-to-use props.
suggestStreamCharts	Recommend realtime charts from a stream schema, throughput, and retention hints.
suggestDashboard	Build a multi-panel dashboard suggestion that covers distinct analytical intents.
suggestStretchCharts	Recommend audience-literacy stretch picks from an AudienceProfile.
repairChartConfig	Check whether a requested chart fits a dataset and return ranked alternatives when it does not.
interrogateChart	Return a statistical summary and chart-aware context for answering natural-language questions with optional annotations.
diagnoseConfig	Check a chart configuration for common problems — empty data, bad dimensions, missing accessors, wrong data shape, and more. Returns a human-readable diagnostic report with actionable fixes.
reportIssue	Generate a pre-filled GitHub issue URL for bug reports or feature requests. Pass { title: "...", body: "...", labels: ["bug"] }. Returns a URL the user can open to submit.
applyTheme	List named theme presets or return ThemeProvider/CSS/token usage for a preset such as { name: "tufte" }.

Resources

Resource	Description
semiotic://schema	Full machine-readable component schema JSON.
semiotic://schema-index	Compact discovery index with categories, renderability, import paths, and each component's schema resource URI.
semiotic://schema/{component}	One component's schema, metadata, accessibility guidance, and behavior contracts (for example semiotic://schema/LineChart).
semiotic://components	Backward-compatible component index showing renderable/browser-only status and MCP categories.
semiotic://surface-manifest	Generated inventory of the current AI schema, exports, renderability, tools, resources, and prompts.
semiotic://behavior-contracts	Agent-visible semantic rules for color precedence, required prop combinations, push refs, and renderability.
semiotic://system-prompt	Compact AI instructions with import rules, chart props, SSR guidance, and pitfalls.
semiotic://examples	Copy-paste chart examples by data shape.
ui://semiotic/chart-widget.html	ChatGPT Apps / MCP Apps widget template used by renderInteractiveChart.

Prompts

Prompt	Description
build-semiotic-chart	Reusable workflow for choosing a chart, reading schema, diagnosing props, and rendering a preview.
debug-semiotic-chart	Reusable workflow for debugging invalid props, rendering failures, and issue reports.

Example: get schema for a component

Tool: getSchema
Args: { "component": "LineChart" }
→ Returns: { "name": "LineChart", "description": "...", "parameters": { "properties": { "data": ..., "xAccessor": ..., ... } } }

Example: suggest a chart for your data

Tool: suggestChart
Args: {
  "data": [
    { "month": "Jan", "revenue": 120, "region": "East" },
    { "month": "Feb", "revenue": 180, "region": "West" }
  ]
}
→ Returns:
  1. BarChart (high confidence) — categorical field (region) with values (revenue)
  2. StackedBarChart (medium confidence) — two categorical fields (month, region)
  3. DonutChart (medium confidence) — 2 categories — proportional composition

Example: render a chart

Tool: renderChart
Args: {
  "component": "BarChart",
  "props": {
    "data": [
      { "category": "Q1", "revenue": 120 },
      { "category": "Q2", "revenue": 180 },
      { "category": "Q3", "revenue": 150 }
    ],
    "categoryAccessor": "category",
    "valueAccessor": "revenue"
  }
}
→ Returns: <svg>...</svg>

Example: render a ChatGPT Apps widget

Tool: renderInteractiveChart
Args: {
  "component": "BarChart",
  "props": {
    "title": "Revenue by Quarter",
    "data": [
      { "quarter": "Q1", "revenue": 120 },
      { "quarter": "Q2", "revenue": 180 }
    ],
    "categoryAccessor": "quarter",
    "valueAccessor": "revenue"
  }
}
→ Returns: structured chart summary for the model + hidden SVG/widget metadata for ChatGPT.

Example: diagnose a broken config

Tool: diagnoseConfig
Args: { "component": "LineChart", "props": { "data": [] } }
→ Returns: ✗ [EMPTY_DATA] data is an empty array — Fix: provide at least one data point

Example: report an issue

Tool: reportIssue
Args: {
  "title": "Bug: BarChart tooltip shows undefined for custom accessor",
  "body": "When using valueAccessor='amount', tooltip displays 'undefined'.\n\ndiagnoseConfig output: ✓ no issues detected.",
  "labels": ["bug"]
}
→ Returns: Open this URL to submit the issue: https://github.com/nteract/semiotic/issues/new?...

CLI alternative

For quick validation without an MCP client:

npx semiotic-ai --list         # list components with import paths and renderability
npx semiotic-ai --list --json  # machine-readable component index
npx semiotic-ai --schema GaugeChart
npx semiotic-ai --suggest '{"data":[{"category":"A","value":10}],"intent":"comparison"}'
npx semiotic-ai --doctor       # validate component + props JSON
npx semiotic-ai --schema       # dump all chart schemas
npx semiotic-ai --compact      # compact schema (fewer tokens)

--doctor uses the full diagnoseConfig checks when dist is available and falls back to schema-only validation in clean source checkouts.

Where to find Semiotic for AI assistants

Semiotic is indexed by AI-coding-agent documentation tools so your assistant (Claude Code, Cursor, Cline, Copilot, etc.) can pull current docs and tools without copy-paste:

• Context7 — context7.com/nteract/semiotic (configured via context7.json)
• DeepWiki — deepwiki.com/nteract/semiotic
• GitMCP — gitmcp.io/nteract/semiotic (exposes the repo as an MCP endpoint directly)
• Official MCP Registry — search "semiotic" at registry.modelcontextprotocol.io

The Official MCP Registry is the canonical MCP directory record; it is distinct from acceptance into any assistant vendor's curated connector directory. Secondary-directory freshness and release ownership are tracked in MCP_DISTRIBUTION.md.

Agent-facing API surface:

• AGENTS.md is the concise repository development contract and CLAUDE.md imports it for Claude Code. These stay repository-local rather than shipping irrelevant contributor instructions to package consumers.
• ai/reference.md, ai/schema.json, ai/surface-manifest.json, ai/behaviorContracts.cjs, and agent-skill/semiotic-charts/SKILL.md are bundled in the npm tarball (see package.json#files). The reference is the on-demand product guide printed by npx semiotic-ai; the schema, manifest, contracts, and portable skill provide structured generation and validation guidance.
• semiotic.nteract.io/llms.txt + /llms-full.txt — deployed at the docs site per the llms.txt standard. Agents fetch the navigation map (llms.txt) or the full inlined docs (llms-full.txt) over HTTP; they're not part of the npm package itself.

Documentation

Interactive docs and examples

• Getting Started
• Charts — chart types with live examples
• Frames — full Frame API reference
• Features — axes, tooltips, interaction, responsive behavior, and composition
• Annotations — first-class annotation types, design guidance, provenance, and lifecycle
• Cookbook — advanced patterns and recipes
• Playground — interactive prop exploration

Upgrading

• Migration Guide — upgrading from v1.x or v2.x
• Changelog — full release history

Contributing

See CONTRIBUTING.md. Our community follows the nteract Code of Conduct.

Acknowledgments

Development of this library owes a lot to Susie Lu, Jason Reid, James Womack, Matt Herman, Shelby Sturgis, and Tristan Reid.

The Sankey layout engine is based on sankey-plus by Tom Shanley, which improved on his earlier d3-sankey-circular with better cycle detection, hierarchical arc stacking, and dynamic extent adjustment.

Semiotic icon based on an icon by Andre Schauer.

License

Apache 2.0