refinedtorrent

A BitTorrent client written from scratch, implementing the peer wire protocol and HTTP tracker communication directly from the BitTorrent spec — no external torrent/bencode libraries doing the heavy lifting.

Built as a learning project to understand how BitTorrent actually works under the hood

What it does

• Parses .torrent files
• Announces to HTTP(S) trackers and parses the compact peer list response
• Performs the BitTorrent handshake and peer wire protocol messaging
• Downloads from multiple peers concurrently, with:
  • Per-piece SHA1 hash verification against the .torrent file's piece hashes
  • Automatic requeueing of a piece if a peer disconnects or sends bad data mid-download, so no peer failure stalls the download
• Live terminal progress bar

What it does not do (I might implement these later)

This was a learning project, not a full BitTorrent client:

• No DHT or Peer Exchange — peer discovery relies entirely on the torrent's HTTP tracker
• No magnet link support — only .torrent files
• No UDP tracker support — HTTP(S) trackers only
• Single-file torrents only — multi-file torrent support is not implemented
• Download only — no seeding/uploading

Because of this, the client works best against torrents with a healthy HTTP tracker (e.g. official Linux distro ISOs), and won't find peers for trackerless/DHT-only torrents.

Showcase

Video of downloading a sample.txt file and debian ISO and matching the ISO's SHA256 with the published checksum

torrentclientshowcase.mp4

Notes

• Debugging networking conditions that don't show up in a toy example: rate limiting/throttling, and connectivity issues caused by CGNAT (My ISP 😡)
• Verifying correctness — the final downloaded file's SHA256 matched the official published checksum exactly

How to run

git clone https://github.com/RefinedDev/refinedtorrent.git
cd refinedtorrent
cargo run --release -- <path/to/torrent_file>

For more information, try --help.

License

Dual-licensed under MIT or Apache-2.0