Frontend Deposit

Frontend Deposit on Base

deposit()

deposit() is a function from privacycash-evm used to deposit ETH into the Privacy Cash protocol on Base.

Parameters

Parameter	Type	Description
depositAmountInput	number	Amount of ETH to deposit (e.g. 0.05).
keyBasePath	string	Base path for the circuit zkey (e.g. '/circuit').
signature	string	Wallet signature of the Privacy Cash sign-in message.
address	string	The depositor’s EVM wallet address.
txSender	Function	Callback to sign and submit the raw transaction: (unsignedTx: any) => Promise<string>.

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Example Usage

'use client'
import { ethers } from 'ethers'
import { deposit } from 'privacycash-evm'
import { useAccount, useWalletClient } from 'wagmi'

export function DepositButton() {
    const { address, connector } = useAccount()
    const { data: walletClient } = useWalletClient()

    const handleDeposit = async () => {
        if (!address) return

        // Retrieve the stored signature
        const signature = localStorage.getItem(`evm_sign_${address}`)
        if (!signature) {
            alert('Please sign in first.')
            return
        }

        // Build the txSender callback
        const txSender = async (unsignedTx: any) => {
            if (walletClient) {
                return await walletClient.sendTransaction({
                    to: unsignedTx.to as `0x${string}`,
                    data: unsignedTx.data as `0x${string}`,
                    value: BigInt(unsignedTx.value?.toString() ?? '0'),
                })
            }
            // Fallback via ethers BrowserProvider
            const ethereum = await connector?.getProvider()
            const provider = new ethers.BrowserProvider(ethereum as any)
            const signer = await provider.getSigner(address)
            const tx = await signer.sendTransaction(unsignedTx)
            return tx.hash
        }

        const txHash = await deposit({
            depositAmountInput: 0.01,
            keyBasePath: '/circuit',
            signature,
            address,
            txSender,
        })

        console.log('Deposit tx:', txHash)
    }

    return <button onClick={handleDeposit}>Deposit 0.01 ETH</button>
}

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Notes

• The txSender callback receives an unsigned transaction object. Your implementation must sign and submit it, then return the transaction hash as a string.
• Always check that the user is on Base mainnet (chainId === 8453) before calling deposit().
• A small additional amount (~0.0001 ETH) is needed to cover the Base network fee on top of the deposit amount. Validate balance >= depositAmountInput + 0.0001 before proceeding.