@libp2p/fetch

Implementation of the Fetch Protocol

About

An implementation of the Fetch protocol as described here: https://github.com/libp2p/specs/tree/master/fetch

The fetch protocol is a simple protocol for requesting a value corresponding to a key from a peer.

Example

import { createLibp2p } from 'libp2p'
import { fetch } from '@libp2p/fetch'

const libp2p = await createLibp2p({
  services: {
    fetch: fetch()
  }
})

// Given a key (as a string) returns a value (as a Uint8Array), or null if the key isn't found.
// All keys must be prefixed my the same prefix, which will be used to find the appropriate key
// lookup function.
async function my_subsystem_key_lookup(key) {
  // app specific callback to lookup key-value pairs.
}

// Enable this peer to respond to fetch requests for keys that begin with '/my_subsystem_key_prefix/'
libp2p.fetch.registerLookupFunction('/my_subsystem_key_prefix/', my_subsystem_key_lookup)

const key = '/my_subsystem_key_prefix/{...}'
const peerDst = PeerId.parse('Qmfoo...') // or Multiaddr instance
const value = await libp2p.fetch(peerDst, key)

Install

$ npm i @libp2p/fetch

Browser <script> tag

Loading this module through a script tag will make it's exports available as Libp2pFetch in the global namespace.

<script src="https://unpkg.com/@libp2p/fetch/dist/index.min.js"></script>

API Docs

• https://libp2p.github.io/js-libp2p/modules/_libp2p_fetch.html

License

Licensed under either of

• Apache 2.0, (LICENSE-APACHE / http://www.apache.org/licenses/LICENSE-2.0)
• MIT (LICENSE-MIT / http://opensource.org/licenses/MIT)

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.