Using Web3 from ContractKit
How to use Web3 from ContractKit to read data from the Celo blockchain.
As of block height 31,056,500 (March 26, 2025, 3:00 AM UTC), Celo is no longer a standalone Layer 1 blockchain—it is now an Ethereum Layer 2! Some documentation may be outdated as updates are in progress. If you encounter issues, please file a bug report.
For the most up-to-date information, refer to our Celo L2 documentation.
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.