Using Web3 from ContractKit
How to use Web3 from ContractKit to read data from the Celo blockchain.
Although the Web3 library was intended to be used only with Ethereum, due to the nature of Celo, we can still use the majority of its features.
The ContractKit, for every interaction with the node, uses internally a Web3 instance.
Because of this, the Ethereum JSON-RPC calls done via the web3 (except some specific calls that we will explain in this page) are also supported
For example:
const web3 = kit.web3;
web3.eth.getBalance(someAddress);
or
const web3 = kit.web3;
web3.eth.getBlock("latest");
will work the same way.
Web3 limitations
As you have read in our guide, Celo uses an extra field: feeCurrency, that allows you to pay gas with ERC20 Tokens.
To facilitate the life of every developer, we decided to wrap the Provider set in the Web3 instance, and add our way to handle local signing using these new fields. Similar to what Metamask does, we intercept every transaction and perform a local signing when required. This wrapper is called CeloProvider.
This let you use the Web3 instance to interact with node's Json RPC API in a transparent way, just deciding which Provider do you need.
This is also the reason that the Kit requires a valid provider from the beginning.
Local Signing
As part of the Donut hardfork network upgrade that occurred on May 19th, 2021, the Celo network now accepts Ethereum-style transactions as well as Celo transactions. This means that you can use Ethereum transaction signing tools (like Metamask, web3.js and ethers.js) to sign transactions for the Celo network. Remember that Celo is a separate layer 1 blockchain from Ethereum, so do not send Ethereum assets directly to your Celo account address on Ethereum.