Hypercore

Hypercore is a secure, distributed append-only log for sharing large datasets and realtime streams. It supports sparse replication, verified reads, optional block encryption, and session-based workflows for building higher-level local-first and peer-to-peer data structures.

Install

npm i hypercore

Quickstart

import Hypercore from 'hypercore'

const core = new Hypercore('./my-first-core', { valueEncoding: 'utf-8' })
await core.ready()

await core.append('hello')
await core.append('from hypercore')

console.log('length:', core.length)
console.log('first block:', await core.get(0))
console.log('second block:', await core.get(1))

for await (const block of core.createReadStream()) {
  console.log('streamed:', block)
}

await core.close()

API Reference

Constructors and sessions

Writing and local mutation

Reading, streams, and proofs

Extensions and replication

Storage inspection and mark-and-sweep

Lifecycle and local configuration

Properties

Events

Static helpers

Types

Errors

Coded errors this module can throw — catch them via err.code.

See also

• Replicate and persist with Hypercore—pair a single core with peer discovery and replication.
• Work with many Hypercores using Corestore—recommended pattern when one process manages multiple cores.
• Corestore—helper reference for creating, naming, and co-replicating groups of Hypercores.
• Hyperbee—sorted key/value B-tree built directly on top of a Hypercore.
• Hyperdrive—filesystem abstraction whose metadata and blob stores are Hypercore-backed.
• Compact encoding—binary encoding toolkit used to structure Hypercore block payloads.