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Overview

This guide covers all EVM-compatible networks supported by Layerswap, including Ethereum, Arbitrum, Optimism, Base, Polygon, Linea, zkSync Era, Scroll, and others. Prerequisites:
  • viem (recommended) or ethers.js
  • A wallet client or signer with funds on the source network

call_data Format

For EVM chains, call_data is a hex-encoded string (0x...) representing the transaction’s data field. It always carries a Layerswap memo (a fixed prefix followed by a sequence number) that the backend uses to match the deposit:
  • Native token transfers (ETH, MATIC, etc.): call_data is the memo hex. to_address is the deposit address and amount / amount_in_base_units carry the value to send.
  • ERC-20 token transfers: call_data is the encoded transfer(address,uint256) function call with the memo hex appended. to_address is the token contract, and amount / amount_in_base_units are 0 — the actual transfer value is encoded inside call_data.
In both cases, build the transaction with to: to_address, value: amount, and data: call_data and the wallet will route it correctly.

Transaction Construction

1

Parse the transfer action

Extract call_data, to_address, amount, and network.chain_id from the transfer action.
2

Build the transaction

Construct a transaction object with the transfer action fields mapped to standard EVM transaction parameters.
3

Estimate gas (optional)

Call eth_estimateGas for a more accurate gas limit. If estimation fails, the transaction can still be sent without an explicit gas limit — the wallet or node will estimate it.
4

Send the transaction

Sign and broadcast the transaction, then return the hash.

Full Example

Pick the library that fits your stack. The viem and ethers.js tabs cover server-side or Node.js usage. The wagmi tab is for browser-side use with a connected wallet.
When using a browser wallet (wagmi), ensure the user is connected to the correct chain (network.chain_id). If not, prompt them to switch networks before sending the transaction.

Next Step

After the transaction is submitted, notify Layerswap so it can match your deposit faster:
See the full deposit flow for details.