BrowserTorrent

A modern, browser-native BitTorrent client, library, and PWA built in TypeScript with Deno, WebRTC, OPFS (Origin Private File System), and BeerCSS.

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🚀 Overview

BrowserTorrent is a zero-dependency, browser-first BitTorrent client engineered to operate 100% within modern web browsers. It provides direct peer-to-peer data transfers over WebRTC DataChannels and communicates with both public WebTorrent WebSocket trackers and built-in Deno-based WebSocket trackers (WsTracker).

Available on JSR as @vanaware/browsertorrent.

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📦 Quick Start

1. Deno (via JSR)

deno add jsr:@vanaware/browsertorrent

import { Client } from "jsr:@vanaware/browsertorrent";

const client = new Client();

// Seed a file directly from the browser
const file = new File(["Hello WebRTC P2P!"], "hello.txt", { type: "text/plain" });
const torrent = await client.seed(file);

console.log("Seeding InfoHash:", torrent.infoHash);
console.log("Magnet URI:", torrent.magnetURI);

2. Browser / ESM

import { Client } from "https://esm.sh/jsr/@vanaware/browsertorrent";

const client = new Client();
const torrent = await client.add("magnet:?xt=urn:btih:...");

torrent.on("download", (bytes) => {
  console.log(`Progress: ${(torrent.progress * 100).toFixed(1)}%`);
});

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🧩 Modular Subpath Exports

Module	Purpose
@vanaware/browsertorrent	Core client, torrent engine, swarm coordinator, bencode, and wire protocols.
@vanaware/browsertorrent/service-worker	Decoupled streaming fetch interceptor and registration helpers for P2P video/audio playback.
@vanaware/browsertorrent/server	In-browser HTTP server bridge for Service Worker streaming.
@vanaware/browsertorrent/torrent-generator	High-speed torrent metainfo generator over Origin Private File System (OPFS).

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✨ Key Features

• Pure Deno & Web Standards: Zero Node.js runtime dependencies; uses standard Uint8Array, EventTarget, and ReadableStream.
• Decoupled Service Worker Streaming: Real-time HTTP 206 Partial Content range requests streaming directly into HTML5 <video> and <audio> tags.
• WebRTC P2P DataChannels: Binary ArrayBuffer transport with automatic framing and backpressure management.
• Full BitTorrent Wire Protocol: Supports BEP 3 wire protocol, BEP 52 v2 Merkle hashing, BEP 6 fast extension, and BEP 10 extension protocol.
• Metadata Exchange (ut_metadata / BEP 9): Piecewise metainfo retrieval for magnet links directly across WebRTC swarms.
• Bi-directional WebRTC Signaling: 100% interoperable with bittorrent-tracker WebSocket JSON specification and public trackers (wss://tracker.webtorrent.dev).
• OPFS & In-Memory Storage: High-performance persistence via FileSystemSyncAccessHandle in dedicated workers.
• Responsive UI: Built with @preact/signals and BeerCSS (Material Design 3).

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🧪 Testing & Verification

BrowserTorrent includes a comprehensive test suite of 700+ unit, integration, and E2E tests:

# Run full unit and integration test suite
deno task test

# Run build orchestrator (esbuild + Deno.bundle)
deno task build

# Run linting and type checks
deno task lint
deno task check

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📚 Documentation & Integration Guides

• Integration & Import Guide
• API Reference
• WebTorrent vs BrowserTorrent Comparison Table
• WebRTC Signaling Architecture