Using Web3 from the Kit

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


const web3 = kit.web3

will work the same way

Web3 limitations

As you have read in our guide, Celo uses some extra fields: feeCurrency, gatewayFeeRecipient and gatewayFee, that among other things allows you to pay gas with ERC20 Tokens. These fields are expected by the node.

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 Problem

Web3 provides an alternative way to locally sign transactions which is the usage of web3.eth.accounts.signTransaction module to register local accounts, but since Celo transactions are different to the Ethereum ones, this does not work with Celo, hence you must not use it.