# Flint

> MIT chart language and MCP server that turns short specs into polished charts

**Category:** Libraries  
**Pricing:** open-source  
**URL:** https://microsoft.github.io/flint-chart/  
**GitHub:** https://github.com/microsoft/flint-chart  
**Added:** 2026-10-19

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## The Hook

Flint is a chart spec from Microsoft built for agents: you (or a model) describe what each field means and which chart you want, and Flint works out scales, axes, spacing, labels and layout, then compiles to Vega-Lite, ECharts, Chart.js, Plotly or a native Excel chart.

## What's Good

MIT (microsoft/flint-chart), release 0.5.1 (2026-08-14). 70+ semantic types (Rank, Price, Country and so on) drive layout decisions that agents usually get wrong by hand. A formal theme spec applies a house style across a whole chart library, with presets in the style of the NYT, Economist, Swiss and McKinsey. npm install flint-chart for the library; npx -y flint-chart-mcp runs a local MCP server that lets an agent pick a template, validate it and open an interactive chart view. Backed by an arXiv paper. ★~4.4k.

## The Catch

Pre-1.0, so the spec can still move. The Python package is not released yet; the port in the repo is a source-only preview. The README pushes a hosted MCP endpoint first; for private or large data, run the local server instead. It is a layer on top of existing chart libraries, so you still ship Vega-Lite, ECharts or Plotly to render.

## Verdict

A sensible middle layer when agents draw your charts — pin the version while it is pre-1.0.