Gossipsub support and Promisify API

# ๐Ÿ”ฆ Highlights

# ๐Ÿ—ฃ Gossipsub

Thanks to the awesome work of the ChainSafe (opens new window) team, Gossipsub (opens new window) is here! Gossipsub is a much more efficient pubsub router than Floodsub. Intead of broadcasting to all of its peers, it broadcasts to a controlled subset of peers. To learn more about how Gossipsub works and where it differs from Floodsub, check out the Spec (opens new window).

If you are using Pubsub you can now switch to using Gossipsub instead of Floodsub. Have old peers you need to flood stuff to? Don't worry, Gossipsub will automatically fallback to Floodsub for peers that don't support it. See the API Changes section below for how to migrate your config over to using Gossipsub.

# ๐Ÿš‰ Promisify

As we migrate to async/await (opens new window) we are promisifying the Libp2p public methods. Several lower level libraries are currently leveraging libp2p for testing. Their transition to full async/await will be greatly helped by promisifying the libp2p API. Once the async/await changes are propagated up, we will remove Promisify in a future update, along with callback support, as libp2p will have full async/await support at that time. See the API Changes below to check out the Breaking Changes.

# ๐Ÿ— API Changes


# Configuration

# Switch Options

Configuration for libp2p-switch has changed. blacklistTTL and blackListAttempts have been changed to denyTTL and denyAttempts respectively. You can set these as follows:

const libp2p = new Libp2p({
  switch: {
    denyTTL: 120e3,
    denyAttempts: 5,

# Pubsub

Subscribe: To comply with the pubsub interface (opens new window), the order of params for libp2p.pubsub.subscribe have been reordered. They were previously topic, options, handler, callback, and are now topic, handler, options, callback. If your implementation does not use options you should be able to ignore this change.

Config: Pubsub was previously enabled via the EXPERIMENTAL config. You must now specify your pubsub implementation (Gossipsub or Floodsub), and enable/disable it via it's own configuration. Setting pubsub will automatically enable it. You can disable it by explicitly setting enabled to false in the configuration .

const libp2p = new Libp2p({
  modules: {
    pubsub: require('libp2p-gossipsub'),
  config: {
    pubsub: {
      enabled: true

# Promisify

All libp2p public methods have been promisified, so callbacks can be omitted in favor of promise based usage, including async/await. For example, start can be used as:

// or
await libp2p.start()

# Gossipsub

Gossipsub is integrated into the existing libp2p.pubsub API (opens new window). Once Gossipsub has been supplied as your pubsub implementation, you will be able to use it just as Floodsub was previously used. See the section above for pubsub configuration changes.

# โค๏ธ Huge thank you to everyone that made this release possible

In alphabetical order, here are the 38 humans that made 429 contributions to this release:

# ๐Ÿ™Œ๐Ÿฝ Want to contribute?

Would you like to contribute to the libp2p project and don't know how? Well, there are a few places you can get started:

  • Check the issues with the help wanted label in the libp2p repo (opens new window)
  • Join an IPFS All Hands, introduce yourself and let us know where you would like to contribute - https://github.com/ipfs/team-mgmt#all-hands-call
  • Hack with IPFS and show us what you made! The All Hands call is also the perfect venue for demos, join in and show us what you built
  • Join the discussion at http://discuss.libp2p.io/ and help users finding their answers.
  • Join the โšก๏ธLibp2p Team Sync ๐Ÿ™Œ๐Ÿฝ (opens new window) and be part of the Sprint action!

# โ‰๏ธ Do you have questions?

The best place to ask your questions about libp2p, how it works and what you can do with it is at discuss.libp2p.io (opens new window). We are also available at the #libp2p channel on Freenode.