Multicall Client for Ethereum

This package provides a Go implementation of the Ethereum Multicall3 contract, enabling efficient batched calls to on-chain contracts using the Ethereum JSON-RPC API. It simplifies making multiple contract read-only (view) calls in a single network request.

Features

• Multicall Support: Aggregate multiple contract calls into a single request, saving on network requests and gas.
• Batching: Automatically handles batching of requests when the size exceeds a defined limit.
• Customizable: Supports custom block height, batching sizes, and deserialization functions.

Table of Contents

• Installation
• Usage
  • Creating the Client
  • Getting Balance
  • Getting Block Number
  • Custom Contract Calls
• Testing
• License

Installation

Install the Go package via:

go get github.com/jbrower95/multicall-go

Usage

Creating the Client

To create a MulticallClient, pass a context.Context, an ethclient.Client, and optional settings.

client, _ := ethclient.Dial("https://your_rpc_url")
ctx := context.Background()
mc, _ := multicall.NewMulticallClient(ctx, client, nil)

Performing two RPC calls at once

You can perform three kinds of actions;

• Checking the balance of an address
• Fetching the block number that the multicall was read from, and
• Performing an arbitrary smart contract read

In this example, we fetch the balance of 0xdeadbeefdeadbeef while also fetching the current block number. We use Do() for this.

balanceCall := multicallClient.GetBalance(common.HexToAddress("0xdeadbeefdeadbeef"))
blockNumberCall := multicallClient.GetBlockNumber()

balance, blockNumber, _ := multicall.Do(multicallClient, balanceCall, blockNumberCall)
fmt.Println("Balance:", balance, "Block Number:", blockNumber)

Performing list of RPC calls

Use DoMany to perform many similarly-typed RPC calls at once:

calls := []*multicall.MultiCallMetaData[big.Int]{
    multicallClient.GetBalance(common.HexToAddress("0xAddress1")),
    multicallClient.GetBalance(common.HexToAddress("0xAddress2")),
}

results, _ := multicall.DoMany(multicallClient, calls...)
for i, result := range *results {
    fmt.Printf("Call %d result: %v\n", i+1, result)
}

Testing

go test is run automatically in CI.