Autobase

The experimental P2P /db notes example allows two writers to edit offline and converge after reconnecting.

How it works

Autobase orders independent writer logs and runs your reducer to produce a shared view. Your reducer determines what an operation means.

The small example uses one writer to show append → apply → view. Follow the collaborative notes guide next to run offline edits with two writers.

The P2P /db prototype uses Autobase. It is distinct from the separate experimental Autobee scaffold.

Run an example

Use Node 22.17+ and npm for installation. Start in a new directory for this example so its ./data storage cannot collide with another example. Save each file below with the exact filename shown, then run the commands in order.

mkdir autobase-demo
cd autobase-demo
npm init -y
npm install autobase@'7.28.2' corestore@'^7.13.0'

Save as example.mjs:

import Autobase from 'autobase'
import Corestore from 'corestore'
const store = new Corestore('./data')
const base = new Autobase(store, null, {
  valueEncoding: 'json',
  open (store) { return store.get({ name: 'view', valueEncoding: 'json' }) },
  async apply (nodes, view) {
    for (const node of nodes) {
      if (node.value !== null) await view.append(node.value)
    }
  },
  async close (view) { await view.close() }
})
try {
  await base.ready()
  await base.append({ text: 'Hello ordered view' })
  await base.update()
  console.log((await base.view.get(base.view.length - 1)).text)
} finally {
  await base.close()
  await store.close()
}

Run from this example directory:

node example.mjs

Expected result

Hello ordered view

API essentials

• new Autobase(store, key, { open, apply }): create a base or join by key and define its view.
• append(operation) and update(): write locally and process available operations. Read the derived result from base.view.
• close(): close the base before its store. Multi-writer applications also need explicit admission rules and indexer availability.

Troubleshooting and limits

• Keep apply deterministic: no random values, current timestamps or external service calls inside the reducer.
• An append or locally updated view does not prove every peer has received or durably indexed it.
• Pairing and database write authority are different permissions; the /db prototype manages membership separately.

Next steps