getMultichainContract

Creates a contract instance that can encode function calls and read state across multiple chains. The SDK provides several pre-configured multichain contracts like mcUSDC, mcUniswapSwapRouter, and mcAaveV3Pool that can be used out of the box.

Usage

import { arbitrumSepolia, optimismSepolia, baseSepolia } from "viem/chains"
import { getMultichainContract, UniswapSwapRouterAbi } from "@biconomy/abstractjs"
import { erc20Abi } from "viem"
 
const mcUniswapSwapRouter = getMultichainContract<typeof UniswapSwapRouterAbi>({
  abi: UniswapSwapRouterAbi,
  deployments: [
    ["0x101F443B4d1b059569D643917553c771E1b9663E", arbitrumSepolia.id],
    ["0x94cC0AaC535CCDB3C01d6787D6413C739ae12bc4", optimismSepolia.id],
    ["0x94cC0AaC535CCDB3C01d6787D6413C739ae12bc4", baseSepolia.id]
  ]
})
 
// Encode a uniswap swap on Base
const swap = mcUniswapSwapRouter.build({
  type: "exactInputSingle",
  data: {
    chainId: baseSepolia.id,
    args: [{
      tokenIn: usdc,
      tokenOut: fuse,
      fee: 3000,
      recipient: account.address,
      deadline: BigInt(Math.floor(Date.now() / 1000) + 900),
      amountIn: safeMultiplier(sellAmount, 0.8), // Composability coming soon...
      amountOutMinimum: 1n,
      sqrtPriceLimitX96: 0n
    }],
    // Some complex userOps will sometimes require more gas than the default. All surpluses are returned to the users smart account in native token
    gasLimit: 1000000n
  }
})
 
// The multichainContract.build() result can be passed to a get{Quote,FusionQuote} call, 
// in the same way that you might pass a mcNexus.build() result
const quote = await mcNexus.getQuote({
  instructions: [..., swap, ...],
  feeToken: { ... }
})

Parameters

Property	Type	Required	Description
abi	Abi	Yes	The contract's ABI
deployments	[Address, number][]	Yes	Array of tuples containing [address, chainId] for each deployment

Response

Returns a MultichainContract instance with the following methods:

Method	Description
on(chainId)	Returns a chain-specific contract instance
read(params)	Reads contract state across multiple chains
build(params)	Builds an instruction for function execution
addressOn(chainId)	Gets contract address for specific chain

Pre-configured Contracts

The SDK provides several pre-configured multichain contracts:

mcUSDC - USDC token contract (source: https://github.com/bcnmy/abstractjs/blob/develop/src/sdk/constants/tokens/__AUTO_GENERATED__.ts#L18)
mcUniswapSwapRouter - Uniswap SwapRouter contract (source: https://github.com/bcnmy/abstractjs/blob/develop/src/sdk/constants/protocols/index.ts#L29)
mcAaveV3Pool - Aave V3 Pool contract (source: https://github.com/bcnmy/abstractjs/blob/develop/src/sdk/constants/protocols/index.ts#L19)

Example

import { getMultichainContract } from "@biconomy/abstractjs"
import { erc20Abi } from "viem"
import { optimism, base } from "viem/chains"
 
// Create a multichain contract instance
const myToken = getMultichainContract({
  abi: erc20Abi,
  deployments: [
    ["0x1234...5678", optimism.id], // Optimism deployment
    ["0x8765...4321", base.id]      // Base deployment
  ]
})
 
// Build a transfer instruction
const instruction = await myToken.build({
  type: "transfer",
  data: {
    chainId: optimism.id,
    args: [recipient, amount]
  }
})
 
// Read balances across chains
const balances = await myToken.read({
  onChains: [optimism, base],
  functionName: "balanceOf",
  args: [address],
  account: smartAccount
})