Basic Swap

This guide walks through a complete swap using the TypeScript SDK - from client setup to execution.

Full Example

import { createPublicClient, createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";
import { EvixClient } from "./sdk";

// 1. Setup
const PRIVATE_KEY = "0x..." as `0x${string}`;
const EVIX_ADDRESS = "0x..." as `0x${string}`;

const account = privateKeyToAccount(PRIVATE_KEY);

const publicClient = createPublicClient({
  chain: base,
  transport: http(),
});

const walletClient = createWalletClient({
  account,
  chain: base,
  transport: http(),
});

const evix = new EvixClient({
  chainId: base.id,
  contractAddress: EVIX_ADDRESS,
  publicClient,
  walletClient,
});

// 2. Define swap parameters
const TOKEN_IN = "0x..." as `0x${string}`;
const TOKEN_OUT = "0x..." as `0x${string}`;
const AMOUNT_IN = 1_000_000n;

async function main() {
  // 3. Execute the swap with your own minAmountOut
  const result = await evix.swap({
    tokenIn: TOKEN_IN,
    tokenOut: TOKEN_OUT,
    amountIn: AMOUNT_IN,
    deadline: BigInt(Math.floor(Date.now() / 1000) + 120),
    minAmountOut: 995_000n, // set by integrator based on own pricing
    recipient: account.address,
  });

  console.log("Swap executed:", {
    amountOut: result.amountOut.toString(),
    tx: result.transactionHash,
  });
}

main().catch(console.error);

Step-by-Step Breakdown

1. Client Setup

The EvixClient requires:

• chainId - The chain ID for your deployment (e.g. 8453 for Base)
• contractAddress - Your provisioned Evix deployment address
• publicClient - A viem PublicClient for reads
• walletClient - A viem WalletClient for transaction execution

2. Setting minAmountOut

The integrator is responsible for determining minAmountOut based on their own pricing, oracle data, or execution model. Evix enforces this value on-chain - if the actual output is lower, the transaction reverts.

3. Execution

swap() submits the transaction and returns the actual output amount and the transaction hash.

caution

Ensure the wallet has sufficient token balance and that the Evix contract has been approved to spend tokenIn via ERC20.approve().

Token Approval

Before your first swap, approve the Evix contract to spend your input token:

import { erc20Abi } from "viem";

const approveTx = await walletClient.writeContract({
  address: TOKEN_IN,
  abi: erc20Abi,
  functionName: "approve",
  args: [EVIX_ADDRESS, AMOUNT_IN],
});

Error Handling

try {
  const result = await evix.swap(params);
} catch (error) {
  // Common revert reasons:
  // - DeadlineExceeded: Transaction landed after deadline
  // - InsufficientOutput: Market moved beyond slippage tolerance
  // - UnsupportedPair: Pair not allowlisted on this deployment
  // - InvalidAmountIn: Zero input amount
  // - InvalidRecipient: Zero address recipient
  console.error("Swap failed:", error);
}