StarGantt

A Gantt chart library where even the basics are plugins — with zero runtime dependencies.

Documentation · Live examples · 日本語版 README (this English README is canonical)

StarGantt is built like VS Code, not like a widget: a micro-kernel of less than 12 KB (minified) that knows nothing about tasks, dates, or drawing, plus 15 official plugins that implement everything else — rendering, drag editing, dependencies, auto-scheduling, critical path, baselines and earned value, resources, import/export, external data sync — using only the same public API that your plugins get. Don't like a built-in behavior? Replace the plugin.

Quick start

<div id="chart" style="height: 480px"></div>
<script src="stargantt.iife.js"></script>
<script>
  const gantt = StarGantt.create({
    element: document.getElementById("chart"),
    plugins: StarGantt.presetStandard(),
  });

  const day = 86400000;
  const t0 = Math.floor(Date.now() / day) * day;
  gantt.service("stargantt.data").load({
    tasks: [
      { id: "root", parentId: null, name: "Release prep", type: "summary", start: t0, end: t0 + 20 * day },
      { id: "spec", parentId: "root", name: "Design", start: t0, end: t0 + 5 * day, progress: 1 },
      { id: "impl", parentId: "root", name: "Implementation", start: t0 + 5 * day, end: t0 + 15 * day, progress: 0.4 },
      { id: "qa", parentId: "root", name: "Verification", start: t0 + 15 * day, end: t0 + 20 * day },
      { id: "ship", parentId: "root", name: "Release", type: "milestone", start: t0 + 20 * day, end: t0 + 20 * day },
    ],
    links: [
      { id: "l1", sourceId: "spec", targetId: "impl", type: "FS" },
      { id: "l2", sourceId: "impl", targetId: "qa", type: "FS" },
      { id: "l3", sourceId: "qa", targetId: "ship", type: "FS" },
    ],
  });
</script>

That is a complete application: one HTML file, one script tag. Styles are injected by create(). Or with a bundler:

import { create, presetStandard } from "stargantt";

const gantt = create({
  element: document.getElementById("chart")!,
  plugins: presetStandard(), // configurable via PresetStandardConfig
});
gantt.service("stargantt.data").load({ tasks, links }); // fully typed

The six opt-in plugins are composed onto the preset by name:

import { create, presetStandard, tracking, resource } from "stargantt";

const gantt = create({
  element,
  plugins: [...presetStandard(), tracking({ baselines: {} }), resource()],
});

Install

npm install stargantt          # everything: core + all 15 official plugins (ESM + IIFE)

Or compose exactly what you need:

npm install @stargantt/core @stargantt/preset-standard
npm install @stargantt/plugin-tracking      # any individual official plugin
npm install @stargantt/sdk                  # for writing your own plugins

Requirements: a desktop/tablet-class viewport (720 × 540 px or larger). There is no mobile-phone layout, by design.

Packages

| Package | What it is | |---|---| | stargantt | Single-file distribution: core + all 15 official plugins, ESM + IIFE, CSS embedded | | @stargantt/preset-standard | The standard 9-plugin composition (presetStandard()) | | @stargantt/core | The micro-kernel (<12 KB minified, enforced in CI) | | @stargantt/sdk | Typed helpers for plugin authors | | @stargantt/plugin-* | The 15 official plugins, individually installable |

Official plugins

Part of presetStandard():

| Plugin | ID | Does | |---|---|---| | data-store | stargantt.data-store | Tasks, links, resources, assignments, custom fields; every change is a reversible transaction | | view | stargantt.view | Renderer, pane layout, theming, timeline axis and header, grid and today line | | tree-grid | stargantt.tree-grid | Left-hand grid pane and row model, field columns, cell editing, rule-driven bar colouring | | task-bars | stargantt.task-bars | Draws the bars; owns the bar geometry every other plugin measures against | | interaction | stargantt.interaction | Selection, drag-edit, snapping, tooltips, context menu, zoom, clipboard, filter/search, edit dialog | | undo-redo | stargantt.undo-redo | Transaction history: undo replays in reverse, redo forward again | | a11y | stargantt.a11y | Keyboard operability and screen-reader support; extensible shortcut table | | scheduling | stargantt.scheduling | Dependency links, auto-schedule engine, working calendars, critical path, diagnostics | | export | stargantt.export | Image/PDF export, CSV/JSON/iCal/MS-Project interchange, .xlsx writer, read-only embed viewing |

Opt-in (bundled, activated by adding their factory to plugins):

| Plugin | ID | Does | |---|---|---| | tracking | stargantt.tracking | Baselines and slip, progress tracking, cost accounting, earned-value management | | resource | stargantt.resource | Resource ledger, assignment editor, resource-axis panel, over-allocation analysis, load chart | | data-sync | stargantt.data-sync | REST/GraphQL snapshots with delta sync and optimistic write-back, offline snapshots, realtime transports | | portfolio | stargantt.portfolio | Initiative–program–project hierarchy and a headless KPI dashboard | | i18n | stargantt.i18n | Locale-keyed dictionary with a fallback chain, shared by all message catalogs | | perf-tools | stargantt.perf-tools | Frame-time overlay and trace recorder for diagnosing paint performance |

Architecture

• The core knows nothing about Gantt charts. It provides a plugin host, services, extension points, an event bus, and a command bus — nothing else. Tasks, dates, and rendering are all plugin territory.
• No back doors. Official plugins are built with exactly the public API third-party plugins get. Anything a built-in plugin can do, yours can too — including replacing a built-in wholesale.
• Deterministic disposal. Every resource a plugin creates (listeners, DOM, timers) is registered through ctx.own(), and the core owns teardown.
• Zero runtime dependencies. Nothing under dependencies except workspace-internal @stargantt/* packages, which are part of the library itself.

The full specification lives in docs/specs/ — architecture.md, the SDK spec, and one spec per plugin.

Documentation

• User documentation — guides, plugin references, and the API reference; every chart on it is a live StarGantt instance.
• Examples — 47 self-contained demo pages, each one HTML file against the released bundle.

Contributing

See CONTRIBUTING.md. Short version: this is a hobby project with no support guarantee; the plugin architecture exists so you can build what you need without waiting for a maintainer. Security reports: see SECURITY.md.

License

MIT © wintermaples