Centrifuge SDK

Centrifuge SDK provides a JavaScript client to interact with Centrifuge Chain. It provides comprehensive modules to easily create and manage pools, nfts, loans and metadata. CentrifugeJS is built on top of @polkadot/api and uses the RxJS API to query chaindata and submit extrinsics.

Installation

1npm install --save @centrifuge/centrifuge-js

Init and config

Create an instance and pass optional configuration

1import Centrifuge from "@centrifuge/centrifuge-js";
2
3const centrifuge = new Centrifuge({
4  centrifugeWsUrl: "wss://fullnode.development.cntrfg.com",
5});

The following config options can be passed on initilization of CentrifugeJS:

network

Default value: centrifuge

Network the instance should run on, either altair or centrifuge.

centrifugeWsUrl

Default value: wss://fullnode.centrifuge.io

Collator websocket URL.

altairWsUrl

Default value: https://api.subquery.network/sq/centrifuge/pools

Altair collator websocket URL.

metadataHost

Default value: https://centrifuge.mypinata.cloud

IPFS gateway url for retrieving metadata.

centrifugeSubqueryUrl

Default value: https://api.subquery.network/sq/centrifuge/pools

Indexed subquery for retrieving historical chain data.

signer

Can either be passed in the config on initialization or can be set programmatically by calling centrifuge.connect(<signing-address>, <signer>)

signingAddress

Can either be passed in the config on initialization or can be set programmatically by calling centrifuge.connect(<signing-address>, <signer>)

pinFile

A function that returns an object { uri: string } containing the URI of the pinned file. This is used to upload and reference metadata in pools, collections and nfts. If not set, pools.createPool, nfts.mintNft etc will not work.

Library structure

Creating a centrifuge instance will give you access to the entire polkadot API and subset of modules to make easier to query and write data. We recommend using Typescript for autocompletion.

The modules include:

• pools
• nfts
• metadata
• and a few more..

Methods are accessed like this:

1// pools
2const data = centrifuge.pools.createPool([...])
3
4// nfts
5const data = centrifuge.nfts.mintNft([...])
6
7// metadata
8const data = centrifuge.metadata.getMetadata("uri")

Queries

All of the CentrifugeJS modules have queries prefixed with get that return Observables.

Here's a full sample how to query all of the pools and subscribe to the state. Behind the scenes the pool data is aggregated from multiple sources and formatted into an object. By subscribing to the observable you're also subscribing to events on-chain that will cause the subscription to update when necessary.

1centrifuge.pools.getPools().subscribe({
2  next: (value) => {
3    console.log("next", value); // Pool[]
4  },
5  complete: () => {
6    console.log("complete");
7  },
8  error: () => {
9    console.log("error");
10  },
11});

Some cases don't require a subscription. We find it easist to use a helper from rxjs to convert the observable into a promise. You'll have to install rxjs

1yarn add --save rxjs

Then the query could look like this

1import { firstValueFrom } from "rxjs";
2
3// ...
4
5const pools = await firstValueFrom(cenrtifuge.pools.getPools()); // Pool[]

Transactions

Transactions/extrinsics require a little more configuration because they need to be signed. Please note that this does not cover how to sign transactions with a proxy.

By connecting the centrifuge instance with a signer, the sourced wallet extension will be triggered to ask for a signature. The signer can be any signer that's compatible with the polkadot API. We use @subwallet/wallet-connect to source multiple wallets.

1// wallet setup imported from @subwallet/wallet-connect/dotsama/wallets
2const wallet = getWalletBySource("polkadot-js");
3await wallet?.enable();
4const accounts = await wallet?.getAccounts();
5
6const signingAddress = accounts?.[0].address as string;
7
8// connect centrifuge to wallet to enable signatures
9const connectedCent = centrifuge.connect(signingAddress, wallet?.signer);
10
11// subscription based
12connectedCent.pools.closeEpoch(["<your-pool-id>"]).subscribe({
13  complete: () => {
14    console.log("Tx complete");
15  }
16});
17
18// or promise based (using firstValueFrom imported from rxjs)
19await firstValueFrom(connectedCent.pools.closeEpoch(["<your-pool-id>"]))

Local development

Install dependencies with yarn or npm.

Start dev server

1yarn start

Running tests

Run test with yarn test

Building for production

Create a bundle in the ./dist folder with yarn build.

Publishing to NPM package registry

Make sure the version in package.json has been increased since the last publish, then push a tag starting with centrifuge-js/v* to kick of the publish Github action.