@tufte/chart-core

Deterministic CSV → Tufte-style ASCII chart renderer, and the reference implementation of the chart format. No dependencies. Because the output is plain text, a rendered chart works anywhere text goes — READMEs, terminals, diffs, LLM context.

import { render } from "@tufte/chart-core";

render(`hbar "Revenue by Quarter ($M)"
Q1, 36
Q2, 43
Q3, 30
Q4, 52`);

Revenue by Quarter ($M)

Q1  ██████████████████████████████  36
Q2  ████████████████████████████████████  43
Q3  █████████████████████████  30
Q4  ████████████████████████████████████████████  52

API

| Export | Purpose | | ----------------------- | ------------------------------------------------------------- | | render(blockText) | Parse a chart block and return ASCII. | | parseChartBlock(text) | Parse to { type, title, options, data }. | | renderSpec(spec) | Render an already-parsed spec. | | renderInline(source) | Render an inline sparkline: 12 24 36 span to glyphs (▁▅█). | | renderInPlace(doc) | Round-trip: render every ```chart block (and inline sparkline) in place. | | GENERATORS | Map of chart type → generator function. |

Chart types: hbar/bar, vbar/column, sparkline, line, table, histogram, progress, scatter. See SPEC.md for the full format.

A sparkline is a single line, so it also works inline within a sentence via a one-backtick `sparkline: 12 24 36` span.

Use from a CDN

Because core is zero-dependency ESM, it loads directly in the browser or Deno — no install, no build step.

Self-hosted (no npm required). A pre-bundled, pinned build is served off tufte.ai:

import { render } from "https://tufte.ai/[email protected]";
// or the always-latest convenience build:
import { render } from "https://tufte.ai/chart-core.js";

npm-backed CDNs (these mirror npm automatically, so they require the package to be published to npm first):

// esm.sh
import { render } from "https://esm.sh/@tufte/[email protected]";

// jsDelivr
import { render } from "https://cdn.jsdelivr.net/npm/@tufte/[email protected]/src/index.js";

// unpkg
import { render } from "https://unpkg.com/@tufte/[email protected]/src/index.js";

Ecosystem

• @tufte/chart-cli — pre-render markdown / stdin → ASCII
• @tufte/markdown-it-chart — markdown-it plugin
• @tufte/remark-chart — remark/unified plugin