Hypercore

The centerpiece of our ecosystem is Hypercore, a secure append-only log data structure. One can think of a Hypercore as a “personal blockchain”, a self-owned list of binary blocks with an immutable history, secured by cryptographic proofs.

var hypercore = require('hypercore')
var feed = hypercore('./my-first-dataset', {valueEncoding: 'utf-8'})

feed.append('hello')
feed.append('world', function (err) {
  if (err) throw err
  feed.get(0, console.log) // prints hello
  feed.get(1, console.log) // prints world
})

Having an immutable history means one can always “check out” the state of a Hypercore at any previous point in time (e.g. when it had a length of 15).

Hypercores can be stored in a variety of different storage backends, so long as they adhere to the random-access-storage pattern. There are random-access-* modules for local disk, memory-only, IndexedDB, S3, and more.