Migrating to ContractKit v1.0

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What is ContractKit version v1.0?

• Reduced bundle size
• Better Typescript support
• Improved maintenance by making it easier to use other libraries

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ContractKit packages

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Main packages

• Connect handles how we communicate to the our chain nodes. It wraps the web3 library and has its own rpcCaller class, to make custom calls to the node. It’s the layer in charge of knowing how and which parameters are added by Celo, connect to the node, build the message, send it and handle those responses.
• ContractKit is a reduced subset of the previous versions of ContractKit. This is the layer in charge of loading and using our core contracts. Internally, uses the connect package described above. It has our contracts generated from the ABIs, their wrappers, and also the logic to make claims.

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Complementary Packages

• Explorer depends on contractkit and connect. It provides some utility functions that make it easy to listen for new block and log information.
• Governance depends on contractkit and explorer. It provides functions to read and interact with Celo Governance Proposals (CGPs).
• Identity simplifies interacting with ODIS, Celo’s lightweight identity layer based on phone numbers.
• Network-utils provides utilities for getting genesis block and static node information.
• Transactions-uri makes it easy to generate Celo transaction URIs and QR codes.

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Wallets and Wallet Utility packages

• Wallet-hsm-azure is a Azure Key Vault implementation of a RemoteWallet.
• Wallet-hsm-aws allows you to easily interact with a cloud HSM wallet built on AWS KMS.
• Wallet-ledger provides utilities for interacting with a Ledger hardware wallet.
• Wallet-localprovides utilities for locally managing wallet by importing a private key string.
• Wallet-rpc provides utilities for performing wallet functions via RPC.
• Wallet-base provides base utilities for creating Celo wallets.
• Wallet-hsm provides signature utilities for using HSMs.
• Wallet-remote provides utilities for interacting with remote wallets. This is useful for interacting with wallets on secure remote servers.

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Importing packages

// Previously this would work to import the block-explorer
import { newBlockExplorer } from "@celo/contractkit/lib/explorer/block-explorer";

// With ContractKit v1.x.y, import the block-explorer explicitly
import { newBlockExplorer } from "@celo/explorer/lib/block-explorer";

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Connecting to the network

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Older versions of ContractKit:

// version ^0.4.0
const ContractKit = require("@celo/contractkit");

// Older versions of ContractKit create a new Web3 instance internally
const kit = ContractKit.newKit("https://forno.celo.org");

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Version 1.x.y

// Since ContractKit no longer instantiates web3, you'll need to explicitly require it
const Web3 = require("web3");
const web3 = new Web3("https://forno.celo.org");

// Require ContractKit and newKitFromWeb3
const { ContractKit, newKitFromWeb3 } = require("@celo/contractkit");
let contractKit = newKitFromWeb3(web3);

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Accessing Web3 functions

// version ^0.4.0
let amount = kit.web3.utils.fromWei("1000000", "ether");

// version 1.x.y
let amount = kit.connection.web3.utils.fromWei("1000000", "ether");

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Backward Compatibility

// This still works
kit.addAccount

// recommended:
kit.connection.addAccount

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Connection package

• kit.web3.eth.isSyncing —> kit.connection.isSyncing
• kit.web3.eth.getBlock —> kit.connection.getBlock
• kit.web3.eth.getBlockNumber —> kit.connection.getBlockNumber
• kit.web3.eth.sign —> kit.connection.sign
• kit.isListening —> kit.connection.isListening
• kit.addAccount —> kit.connection.addAccount