Flint Chart

Flint is a visualization intermediate language from Microsoft Research for agents that generate charts. Instead of having an agent hardcode scales, axes, spacing, labels, and layout, Flint takes a compact semantic chart spec, the data, and an optional visual theme, derives those decisions itself, and compiles the result to a native Vega-Lite, ECharts, Chart.js, or Plotly spec, or to an editable Excel chart.

The spec records what each field means through more than 70 semantic types (such as rank, temperature, price, or country), and layout adapts sizing, labels, marks, and legends to the data's cardinality and the canvas. A theme spec sits beside the chart spec and defines layout behavior, semantic presentation, and visual identity once for a whole chart library. Ten built-in presets include editorial styles modeled on the New York Times, the Economist, Swiss design, and McKinsey, and a custom theme can inherit a preset and override only its brand decisions. Themes currently apply to Vega-Lite and Plotly output.

The project has two parts. The flint-chart JavaScript and TypeScript library takes the same input for every backend and returns that library's native spec object. The flint-chart-mcp server, local or hosted, lets agents choose a chart template, validate it, and open an interactive chart view, static PNG or SVG output, or backend-native specs from a chat or coding environment, with data passed inline or read from local JSON, CSV, or TSV files. A standalone agent skill covers agent workflows without MCP, and a Python port is in preview.