v0.41-v0.42.md

Migrating to libp2p@42

A migration guide for refactoring your application code from libp2p v0.41.x to v0.42.0.

Table of Contents

• libp2p interface
• Connection manager events
• Transport manager

libp2p interface

A definition of the libp2p interface is now available from the module @libp2p/interface-libp2p. This allows modules to signal what fields and methods they expect from a libp2p node without having to depend on the libp2p module directly making it lighter-weight and easier to consume.

Not all fields from the returned object of the createLibp2p are defined on the interface, notably the registrar and connectionManager fields have been removed. The functionality of these fields is available by calling methods on the root libp2p object instead.

Before

import { createLibp2p } from 'libp2p'
import { createTopology } from '@libp2p/topology'

const node = await createLibp2p({
  // ... other options
})

node.registrar.getProtocols()
// ['/ipfs/ping/1.0.0', '/ipfs/id/1.0.0']

node.connectionManager.getConnections()
// [Connection, Connection]

await node.connectionManager.openConnection(peerId)
// Connection

// Topology operations
const id = await node.registrar.register('/my/protocol/1.0.0', createTopology({}))
node.registrar.unregister(id)

After

import { createLibp2p } from 'libp2p'

const node = await createLibp2p({
  // ... other options
})

node.getProtocols()
// ['/ipfs/ping/1.0.0', '/ipfs/id/1.0.0']

node.getConnections()
// [Connection, Connection]

await node.dial(peerId)
// Connection

// Topology operations
const id = await node.register('/my/protocol/1.0.0', createTopology({}))
node.unregister(id)

Connection manager events

The connection manager events peer:connect and peer:disconnect are now emitted by the libp2p node.

Before

import { createLibp2p } from 'libp2p'

const node = await createLibp2p({
  // ... other options
})

node.connectionManager.addEventListener('peer:connect', (event) => {
  // ...
})
node.connectionManager.addEventListener('peer:disconnect', (event) => {
  // ...
})

After

import { createLibp2p } from 'libp2p'

const node = await createLibp2p({
  // ... other options
})

node.addEventListener('peer:connect', (event) => {
  // ...
})
node.addEventListener('peer:disconnect', (event) => {
  // ...
})

Transport manager

The transport manager has been removed from the exports map. To access the FaultTolerance enum, import it from the @libp2p/interface-transport module instead:

import { FaultTolerance } from 'libp2p/transport-manager'

After

import { FaultTolerance } from '@libp2p/interface-transport'