Install

Install agentlet-core from npm:

npm install agentlet-core

This installs version 2.5.0, see it on npm. The package ships dist/agentlet-core.js (IIFE global, also used by require), dist/agentlet-core.min.js, dist/agentlet-core.esm.js, dist/agentlet-core.d.ts, dist/pdf.worker.min.mjs (the matching pdf.js worker, see Public API), the files the core loads on demand, dist/agentlet-core.full.min.js and the pdf.js character maps and fonts, all listed under Size. For a working page in two minutes, see the Quick start. The sizes are under Size.

Works under Node

require('agentlet-core') and import('agentlet-core') load without a browser. Only new AgentletCore().init() needs one: pdf.js, the one dependency that touches browser globals, is not evaluated at import time. Since 2.4.0, SheetJS, html2canvas and pdf.js are loaded the first time a feature needs them, see Size. Up to 2.3.0, pdf.js was loaded inside init() and window.pdfjsLib was available once init() resolved. This makes the package safe to import from server-side rendering, build tools, and tests.

require('agentlet-core/package.json') also works, for tooling that reads the package’s own metadata.

Import forms

// The default export is the class.
import AgentletCore from 'agentlet-core';
import { Dialog, FormExtractor } from 'agentlet-core';

// Exposes the module namespace rather than the class itself, so read the
// class off `default`. This matches the browser global below.
const { default: AgentletCore } = require('agentlet-core');

<script src="node_modules/agentlet-core/dist/agentlet-core.js"></script>
<script>
  const core = new window.AgentletCore.default();
</script>

Named exports such as Dialog, FormExtractor, and TableExtractor work the same way on all three paths.

The package also ships hand-written TypeScript declarations for window.agentlet, the Module base class, and the core config, usable from both JavaScript and TypeScript agentlets. See TypeScript.

Size

Since agentlet-core 2.4.0, SheetJS, html2canvas and pdf.js are not inlined in the core. Each one is loaded the first time a feature needs it: the first Excel export, screenshot or PDF conversion. The package ships these files in dist/:

agentlet-core.js, agentlet-core.min.js and agentlet-core.esm.js: the core alone.
agentlet-xlsx.min.js, agentlet-html2canvas.min.js and agentlet-pdfjs.min.js: the three libraries, which the two IIFE builds load next to the core script. The ES module build reaches them through the ES modules in dist/chunks/, which a bundler turns into its own lazy chunks.
pdf.worker.min.mjs, cmaps/ and standard_fonts/: what pdf.js fetches while it converts a PDF, from the same pdfjs-dist version as the bundled library. The core requests nothing from cdnjs.cloudflare.com.
agentlet-core.full.min.js: the core with all three libraries inlined, as one self-contained file for hosts that cannot serve several files. It registers the libraries during init(), like the single file did up to 2.3.0.

Sizes in 2.4.0, minified, with gzip measured by gzip -c file | wc -c:

File	Size	Gzip	Downloaded
`dist/agentlet-core.min.js` (the core alone)	292 KB	76 KB	always
`dist/agentlet-xlsx.min.js` (SheetJS)	503 KB	162 KB	first Excel export
`dist/agentlet-html2canvas.min.js`	205 KB	48 KB	first screenshot
`dist/agentlet-pdfjs.min.js` (pdf.js)	381 KB	113 KB	first PDF conversion
`dist/pdf.worker.min.mjs`	1.04 MB	286 KB	first PDF conversion
`dist/cmaps/` (169 files) and `dist/standard_fonts/` (16 files)	1.17 MB and 0.78 MB in total		only the files a PDF needs
`dist/agentlet-core.full.min.js` (everything inlined)	1.39 MB	401 KB	always

A page that never exports to Excel, captures the page or converts a PDF downloads 76 KB gzipped. The npm tarball is 3.2 MB, or 9.1 MB unpacked. The browser extension build and the generated bookmarklet carry all three libraries inline.

Up to 2.3.0, every library was inlined: agentlet-core.min.js was 1.38 MB, 398 KB gzipped, downloaded in full on every page where the agentlet ran.

Where the files are loaded from

The IIFE builds resolve every on-demand file relative to the URL of the core script itself. A host that serves the files of dist/ together, whether it loads the core from a CDN with a <script> tag or from its own server, needs no setting. The script tag the core injects has no crossorigin attribute, so the server needs no CORS headers beyond what the core script itself needs. Set these AgentletCore options when the files live elsewhere:

Option	Use
`libraryBaseUrl`	Folder URL that serves the chunk files, `pdf.worker.min.mjs`, `cmaps/` and `standard_fonts/`. Needed when the core is evaluated without a script URL (a `fetch()` plus `eval()` loader), is bundled into the host’s own script, or the files are served from another place. Falls back to the folder of `registryUrl`, then to the extension root inside a browser extension.
`libraryUrls`	URL of a single library file, for example `{ xlsx: 'https://static.example.com/sheetjs.js' }`.
`pdfWorkerUrl`	URL of `pdf.worker.min.mjs`.
`pdfCMapUrl`, `pdfStandardFontsUrl`	URL of the folder with the character maps or the standard fonts.
`preloadLibraries`	`['xlsx', 'html2canvas', 'pdfjs']`, or a subset: load them while `init()` runs instead of on first use.

A failed load rejects with the URL it tried and the option to change. The ES module build needs neither of the first two: import() resolves its chunks relative to the module, and a bundler handles them like any other lazy import. The pdf.js files are plain files, not modules: copy pdf.worker.min.mjs, cmaps/ and standard_fonts/ to where the app serves its assets and point pdfWorkerUrl, pdfCMapUrl and pdfStandardFontsUrl at them. The full list of options is in the Public API.

window.XLSX, window.html2canvas and window.pdfjsLib are no longer defined right after init(), unless you list them in preloadLibraries or use agentlet-core.full.min.js. The asynchronous APIs (tables.download(), ScreenCapture, ai.convertPDFToImages() and the others) load what they need themselves. The synchronous createExcelWorkbook() on the table extractor needs SheetJS loaded first: call await window.agentlet.tables.extractor.ensureXLSX() or preload xlsx.

Clone and build

To contribute to agentlet-core, clone and build it locally instead of installing the package:

git clone https://github.com/agentlet/agentlet-core.git
cd agentlet-core
npm install
npm run build

See Manual setup for what this produces, or Quick demo to run the built-in examples right away.