Papyrus PDF SDK

Open source PDF/EPUB/TXT SDK for web and mobile document readers.

Read this in: English | Portuguese (Brazil)

Papyrus is a modular open source PDF/EPUB/TXT SDK built to power document-heavy products. It combines a core state layer, pluggable engines (PDF.js on web, native on mobile), and UI kits for React and React Native.

Supports PDF, EPUB, and TXT. On mobile, EPUB/TXT render via a WebView runtime while PDF stays native.

Docs

• Configuration guide
• Event hooks
• Mobile (React Native)
• Release / Publish
• Papyrus FAQ
• Open Source PDF SDK
• Open Source EPUB SDK
• Papyrus vs PDFTron
• Best Free PDF SDK 2026

Features

• Event hooks for page, zoom, selection, and annotations
• Document types: PDF, EPUB, TXT
• Background text search with preview
• Themeable UI: light, dark, sepia, high-contrast
• Decoupled architecture: core state, engines, and UI packages

Packages

Package	Responsibility
@papyrus-sdk/types	Shared types and contracts
@papyrus-sdk/core	Store (Zustand), event bus, search service
@papyrus-sdk/engine-pdfjs	PDF.js engine adapter for web
@papyrus-sdk/engine-epub	EPUB engine adapter for web
@papyrus-sdk/engine-text	TXT engine adapter for web
@papyrus-sdk/engine-native	Native engine bridge (iOS/Android)
@papyrus-sdk/ui-react	React UI components
@papyrus-sdk/ui-react-native	React Native UI components
@papyrus-sdk/expo-plugin	Expo config plugin for native builds

Quickstart (web)

npm install
npm run dev

Open the URL printed by Vite.

Minimal usage (web)

import { useViewerStore, papyrusEvents } from '@papyrus-sdk/core';
import { PDFJSEngine } from '@papyrus-sdk/engine-pdfjs';
import { PapyrusConfig, PapyrusEventType } from '@papyrus-sdk/types';
import { Viewer, Topbar, SidebarLeft, SidebarRight } from '@papyrus-sdk/ui-react';

const engine = new PDFJSEngine();

const config: PapyrusConfig = {
  initialUITheme: 'dark',
  initialPage: 1,
  sidebarLeftOpen: true
};

useViewerStore.getState().initializeStore(config);

const bootstrap = async () => {
  await engine.load('/sample.pdf');

  const store = useViewerStore.getState();
  store.setDocumentState({
    isLoaded: true,
    pageCount: engine.getPageCount(),
    outline: await engine.getOutline()
  });
};

bootstrap();

papyrusEvents.on(PapyrusEventType.DOCUMENT_LOADED, ({ pageCount }) => {
  console.log('Loaded pages:', pageCount);
});

// In your React tree:
// <Topbar engine={engine} />
// <SidebarLeft engine={engine} />
// <Viewer engine={engine} />
// <SidebarRight engine={engine} />

Examples

• Web demo: examples/web
• React Native: examples/mobile
• Build packages: pnpm -r --filter "./packages/**" --sort --workspace-concurrency=1 build

Contributing

See CONTRIBUTING.md.

License

MIT. See LICENSE.