Flint Chart is Microsoft’s open-source visualization language for the AI era. It lets AI agents reliably create expressive, good-looking and interactive charts from simple, human-editable chart specifications, instead of wrestling with low-level plotting configuration.
Agents are good at describing data but unreliable at producing polished chart code. Flint closes that gap with a compiler: you describe your data with semantic types (such as YearMonth, Quantity or Temperature), pick a high-level chart type and encodings, and optionally add theme and interaction specs โ the compiler then resolves everything into a complete, backend-native specification. One Flint spec renders across five backends: Vega-Lite, ECharts, Chart.js and Plotly, plus native, editable Excel charts. The library covers 52 chart types, 14 preset themes modeled on styles such as the Economist and the New York Times (with custom ThemeSpecs and inheritance for brand consistency), and 23 interaction presets with a programming API for bespoke behaviors. Flint is available as an npm library with React and vanilla JavaScript APIs, and as an MCP server so agents in tools like Copilot, Claude and Cursor can chart directly in conversation. It is MIT-licensed, has more than 4,300 stars on GitHub, and reached version 1.0 in October 2026.
Free. Flint Chart is open source under the MIT license, including the npm library and the MCP server.
Developers building AI agents, dashboards and data stories who need charts that look professionally designed by default, and agent builders who want reliable, themeable chart generation through an MCP tool.