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Build your own BitTorrent

Learn about .torrent files, the BitTorrent Peer Protocol and more

Start Building
bittorrent
C
bittorrent
C++
bittorrent
C#
bittorrent
Go
bittorrent
Python
bittorrent
Rust
bittorrent
Elixir
bittorrent
Haskell
bittorrent
Java
bittorrent
JavaScript
bittorrent
Kotlin
bittorrent
Ruby
bittorrent
TypeScript
bittorrent
Zig

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BitTorrent is a peer-to-peer file sharing protocol used for distributing large amounts of data. In this challenge, you'll build a BitTorrent client that's capable of downloading a publicly available file using the BitTorrent protocol.

Along the way, you'll learn about the BitTorrent protocol, .torrent files more.

Base Stages

BitTorrent is a peer-to-peer file sharing protocol used for distributing large amounts of data. In this challenge, you'll build a BitTorrent client that's capable of downloading a publicly available file using the BitTorrent protocol.

Along the way, you'll learn about the BitTorrent protocol, .torrent files more.

Decode bencoded strings
Very easy
We'd expect a proficient developer to take < 5 minutes to complete this stage.
Decode bencoded integers
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Decode bencoded lists
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Decode bencoded dictionaries
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Parse torrent file
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Calculate info hash
Medium
We'd expect a proficient developer to take 30 minutes to 1 hour to complete this stage.
Piece hashes
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Discover peers
Medium
We'd expect a proficient developer to take 30 minutes to 1 hour to complete this stage.
Peer handshake
Medium
We'd expect a proficient developer to take 30 minutes to 1 hour to complete this stage.
Download a piece
Hard
We'd expect a proficient developer to take more than 1 hour to complete this stage.
Download the whole file
Hard
We'd expect a proficient developer to take more than 1 hour to complete this stage.

Magnet Links

This extension covers magnet links. Magnet links allow downloading files without the need of downloading a .torrent file first.

Along the way, you'll learn about the magnet URI format, the extension protocol and the metadata extension.

Parse magnet link
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Announce extension support
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Send extension handshake
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Receive extension handshake
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Request metadata
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Receive metadata
Easy
We'd expect a proficient developer to take 5-10 minutes to complete this stage.
Download a piece
Hard
We'd expect a proficient developer to take more than 1 hour to complete this stage.
Download the whole file
Hard
We'd expect a proficient developer to take more than 1 hour to complete this stage.
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