Semiotic

Semiotic is nteract's open-source React data visualization library, built for AI-assisted development: charts, network graphs, streaming data and coordinated views, with schemas, diagnostics and render evidence that let an agent check its own chart work. Its MCP server lets your agent pick, validate, render and repair Semiotic charts through tool calls. What you can do with it - Create a chart from your data and what you want it to show: it picks the chart, validates and diagnoses the settings, renders it and returns render evidence (marks drawn, axis domains, an empty flag) that shows it really drew your data - Improve an existing chart: check whether it fits the data, and get repairs or alternative charts - Audit a chart for design problems, accessibility and mobile layout, with findings in priority order - Explain a chart without pixels: a description, what it's meant to show and a navigable structure of its data - Get the settings schema for any Semiotic component while writing or editing chart code How it connects - Hosted: nteract runs a stable public endpoint at https://semiotic-mcp-server-481507046413.us-west1.run.app/mcp, with no sign-in, redeployed with each release. It serves the five task tools: createChart, improveChart, explainChart, auditChart and getChartSchema. - Local: npx -y -p semiotic semiotic-mcp runs the server over stdio with no API key and the full developer tool set, including renderChart, suggestCharts, diagnoseConfig, repairChartConfig and interrogateChart. Add --profile public for just the five task tools. - In agents that show MCP Apps, such as ChatGPT, charts come back as an interactive widget with fit, zoom, data and render-evidence controls. Good to know - Every tool is read-only: it works on the data and chart settings you give it and changes nothing. - Rendering covers static-data charts; realtime charts need a browser. - Semiotic is open source under the Apache 2.0 license.

• “Make a chart comparing revenue by region from this data.”

  1. createChart
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• “This line chart looks wrong. What's off, and how do I fix it?”

  1. improveChart
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• “Audit this chart for accessibility and how it reads on mobile.”

  1. auditChart
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• “Explain what this chart shows, in words.”