$ show webtorrent/bittorrent-tracker
This repository provides a robust, production-ready implementation of a BitTorrent tracker, including both client and server components. The client can announce to HTTP, UDP, and WebSocket trackers to discover peers in a swarm, while the server can track multiple swarms, respond to announce and scrape requests, and expose statistics via a web interface. The architecture is modular, with separate tracker protocol implementations (HTTP, UDP, WebSocket) inheriting from a common base class, and a server that manages swarms using an LRU cache for peer storage. The codebase is well-tested, uses modern ESM modules, and is actively maintained as part of the WebTorrent ecosystem. It is primarily a library for Node.js, but also supports browser usage via bundlers.
The LLM identified 2 files worth highlighting for reuse:
Implements the core swarm state management for the tracker server. Uses an LRU cache to store peer information with configurable max size and TTL. Handles peer lifecycle events (started, stopped, completed, update, paused) and maintains counts of seeders and leechers. When a peer is evicted from the cache, it automatically sends a synthetic 'stopped' event to keep stats accurate. This component is self-contained and could be extracted as a standalone swarm manager for any P2P tracker system.
WebSocket tracker client implementation with advanced features: socket pooling to share WebSocket connections across multiple tracker clients for the same announce URL, exponential backoff reconnection with jitter, and WebRTC offer/answer exchange for peer signaling. It generates offers with a timeout and handles incoming offers/answers from the tracker. The socket pooling pattern reduces connection overhead and is a reusable design for any WebSocket-based client that needs to share connections.