Flint: A Visualization Language for the AI Era

[![npm: flint-chart](https://img.shields.io/npm/v/flint-chart.svg?label=npm%3A%20flint-chart)](https://www.npmjs.com/package/flint-chart) [![npm: flint-chart-mcp](https://img.shields.io/npm/v/flint-chart-mcp.svg?label=npm%3A%20flint-chart-mcp)](https://www.npmjs.com/package/flint-chart-mcp) [![arXiv: 2607.20775](https://img.shields.io/badge/arXiv-2607.20775-b31b1b.svg)](https://arxiv.org/abs/2607.20775) [![CI](https://github.com/microsoft/flint-chart/actions/workflows/ci.yml/badge.svg)](https://github.com/microsoft/flint-chart/actions/workflows/ci.yml) [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE) **Please visit:** [**Flint Project Site**](https://microsoft.github.io/flint-chart/) | [**MCP Server Guide**](https://microsoft.github.io/flint-chart/#/mcp) | [**中文主页**](https://microsoft.github.io/flint-chart/#/zh) Flint is a visualization intermediate language that lets **AI agents create expressive, polished visualizations from simple, human-editable chart specs**. Instead of asking agents or developers to tune verbose chart configuration details such as scales, axes, spacing, labels, and layout, the Flint compiler derives optimized chart settings from the data, semantic types, chart type, and encodings. The result is a compact chart specification that agents can produce reliably, people can edit directly, and multiple backends can render as native [Vega-Lite](https://vega.github.io/vega-lite/), [ECharts](https://echarts.apache.org/), [Chart.js](https://www.chartjs.org/), or [Plotly](https://plotly.com/javascript/) specs, and native Excel charts through Office.js. This repo contains two main components: - **`flint-chart`**: a JavaScript/TypeScript library that compiles the same Flint input into Vega-Lite, ECharts, Chart.js, Plotly, or Excel-native output. - **`flint-chart-mcp`**: an MCP server that lets agents create, validate, and render charts directly from a chat or coding environment.

A wall of charts produced by Flint across its supported visualization backends.

## Features - **Semantic chart specs.** Flint captures what each field means using 70+ semantic types such as `Rank`, `Temperature`, `Price`, or `Country`. - **Automatic layout.** Flint adapts sizing, spacing, labels, marks, and legends to the data cardinality, chart design, and canvas constraints. - **Multiple backends.** Compile one input to backend-native output across [Vega-Lite](https://vega.github.io/vega-lite/), [ECharts](https://echarts.apache.org/), [Chart.js](https://www.chartjs.org/), [Plotly](https://plotly.com/javascript/), and native Excel charts. - **Agent-ready chart authoring.** The MCP server gives agents Flint tools and chart guidance so they can choose a template, validate it, and open an interactive chart view in MCP-capable clients. ## Updates - **July 24, 2026** — Flint 0.4.0 adds 38 Plotly chart types and 18 native, editable Excel chart templates. ([v0.4.0](https://github.com/microsoft/flint-chart/releases/tag/0.4.0)) - **July 19, 2026** — Flint 0.3.0 adds dynamic chart widgets that switch chart types and edit chart properties in place. ([v0.3.0](https://github.com/microsoft/flint-chart/releases/tag/0.3.0)) - **July 15, 2026** — Flint 0.2.2 added compact dodge modes and grouped violin layouts. - **July 13, 2026** — Flint 0.2.1 improved chart-property validation and backend consistency. ([v0.2.1](https://github.com/microsoft/flint-chart/releases/tag/0.2.1)) See the [changelog](CHANGELOG.md) for complete release notes.

Flint compiling a compact chart spec into a Vega-Lite spec and rendered heatmap visualization.
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Tagged “charting-library”

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flint-chart