IPFS Connection Manager
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JavaScript connection manager for libp2p

Lead Maintainer

Vasco Santos.

Table of Contents



> npm install libp2p-connection-manager

Use in Node.js or in the browser with browserify, webpack or any other bundler

const ConnManager = require('libp2p-connection-manager')


A connection manager manages the peers you're connected to. The application provides one or more limits that will trigger the disconnection of peers. These limits can be any of the following:

  • number of connected peers
  • maximum bandwidth (sent / received or both)
  • maximum event loop delay

The connection manager will disconnect peers (starting from the less important peers) until all the measures are withing the stated limits.

A connection manager first disconnects the peers with the least value. By default all peers have the same importance (1), but the application can define otherwise. Once a peer disconnects the connection manager discards the peer importance. (If necessary, the application should redefine the peer state if the peer is again connected).

Create a ConnectionManager

const libp2p = //
const options = {…}
const connManager = new ConnManager(libp2p, options)

Options is an optional object with the following key-value pairs:

  • maxPeers: number identifying the maximum number of peers the current peer is willing to be connected to before is starts disconnecting. Defaults to Infinity
  • maxPeersPerProtocol: Object with key-value pairs, where a key is the protocol tag (case-insensitive) and the value is a number, representing the maximum number of peers allowing to connect for each protocol. Defaults to {}.
  • minPeers: number identifying the number of peers below which this node will not activate preemptive disconnections. Defaults to 0.
  • maxData: sets the maximum data — in bytes per second - (sent and received) this node is willing to endure before it starts disconnecting peers. Defaults to Infinity.
  • maxSentData: sets the maximum sent data — in bytes per second - this node is willing to endure before it starts disconnecting peers. Defaults to Infinity.
  • maxReceivedData: sets the maximum received data — in bytes per second - this node is willing to endure before it starts disconnecting peers. Defaults to Infinity.
  • maxEventLoopDelay: sets the maximum event loop delay (measured in miliseconds) this node is willing to endure before it starts disconnecting peers. Defaults to Infinity.
  • pollInterval: sets the poll interval (in miliseconds) for assessing the current state and determining if this peer needs to force a disconnect. Defaults to 2000 (2 seconds).
  • movingAverageInterval: the interval used to calculate moving averages (in miliseconds). Defaults to 60000 (1 minute).
  • defaultPeerValue: number between 0 and 1. Defaults to 1.


Starts the connection manager.


Stops the connection manager.

connManager.setPeerValue(peerId, value)

Sets the peer value for a given peer id. This is used to sort peers (in reverse order of value) to determine which to disconnect from first.


  • peerId: B58-encoded string or peer-id instance.
  • value: a number between 0 and 1, which represents a scale of how valuable this given peer id is to the application.


Returns the peers this connection manager is connected to.

Returns an array of PeerInfo.

connManager.emit('limit:exceeded', limitName, measured)

Emitted when a limit is exceeded. Limit names can be:

  • maxPeers
  • minPeers
  • maxData
  • maxSentData
  • maxReceivedData
  • maxEventLoopDelay
  • a protocol tag string (lower-cased)

connManager.emit('disconnect:preemptive', peerId)

Emitted when a peer is about to be preemptively disconnected.

connManager.emit('disconnected', peerId)

Emitted when a peer is disconnected (preemptively or note). If this peer reconnects, you will need to reset it's value, since the connection manager does not remember it.

connManager.emit('connected', peerId: String)

Emitted when a peer connects. This is a good event to set the peer value, so you can get some control over who gets banned once a maximum number of peers is reached.


Feel free to join in. All welcome. Open an issue!

This repository falls under the IPFS Code of Conduct.