Quickstart on Optimism

This page takes you from zero to a cross-network swap sourced from Optimism. No new contracts, no approval for native ETH, one signed transaction for your user.

Building with an AI assistant? Add the SODAX Builders MCP (https://builders.sodax.com/mcp) to Claude, Cursor, or any MCP-capable tool and it can pull live token lists, real quotes, and these docs while it writes your integration.

1. Install

npm install @sodax/sdk @sodax/wallet-sdk-core
# or: pnpm add / yarn add

2. Create an Optimism wallet provider

Optimism uses the same EvmWalletProvider as every other EVM network, keyed by ChainKeys.OPTIMISM_MAINNET.

import { EvmWalletProvider } from '@sodax/wallet-sdk-core';
import { ChainKeys } from '@sodax/sdk';

const walletProvider = new EvmWalletProvider({
  privateKey: '0x…',
  chainId: ChainKeys.OPTIMISM_MAINNET,
  rpcUrl: 'https://mainnet.optimism.io', // OP Mainnet public RPC
});

import { EvmWalletProvider } from '@sodax/wallet-sdk-core';

// walletClient and publicClient are viem clients for OP Mainnet,
// usually supplied by wagmi from the user's connected EVM wallet
const walletProvider = new EvmWalletProvider({
  walletClient,
  publicClient,
});

Building in React? @sodax/wallet-sdk-react connects EVM wallets for you and hands back a ready-made provider via useWalletProvider. See Wallets.

3. Look up supported tokens

Token addresses and decimals come from the SDK config, so you never hard-code them.

import { Sodax, ChainKeys, type XToken } from '@sodax/sdk';

const sodax = new Sodax();

// find() returns XToken | undefined, so narrow before using the address
const bySymbol = (tokens: readonly XToken[], symbol: string) => {
  const token = tokens.find(t => t.symbol === symbol);
  if (!token) throw new Error(`${symbol} is not a supported swap token`);
  return token;
};

const eth = bySymbol(sodax.swaps.getSupportedSwapTokensByChainId(ChainKeys.OPTIMISM_MAINNET), 'ETH');
const usdcBase = bySymbol(sodax.swaps.getSupportedSwapTokensByChainId(ChainKeys.BASE_MAINNET), 'USDC');

4. Quote and swap

swap() runs the full lifecycle: it creates the intent on Optimism, verifies the transaction landed, relays it to the hub, and notifies the solver to fill on the destination network.

import type { SolverIntentQuoteRequest } from '@sodax/sdk';

// 0.1 ETH, built from the token's own decimals (18 for ETH)
const inputAmount = 10n ** BigInt(eth.decimals) / 10n;

// Quote: 0.1 ETH on Optimism -> USDC on Base
const quoteResult = await sodax.swaps.getQuote({
  token_src: eth.address,
  token_dst: usdcBase.address,
  token_src_blockchain_id: ChainKeys.OPTIMISM_MAINNET,
  token_dst_blockchain_id: ChainKeys.BASE_MAINNET,
  amount: inputAmount,
  quote_type: 'exact_input',
} satisfies SolverIntentQuoteRequest);

if (!quoteResult.ok) throw new Error('Quote failed');
const { quoted_amount } = quoteResult.value;

// `deadline` is an absolute Unix timestamp; getSwapDeadline turns an offset into one
const deadlineResult = await sodax.swaps.getSwapDeadline(300n); // 5 minutes from now
if (!deadlineResult.ok) throw new Error('Deadline lookup failed');

// Execute
const swapResult = await sodax.swaps.swap({
  params: {
    inputToken: eth.address,
    outputToken: usdcBase.address,
    inputAmount,
    minOutputAmount: (quoted_amount * 99n) / 100n, // your slippage policy
    deadline: deadlineResult.value,
    allowPartialFill: false,
    srcChainKey: ChainKeys.OPTIMISM_MAINNET,
    dstChainKey: ChainKeys.BASE_MAINNET,
    srcAddress: await walletProvider.getWalletAddress(),
    dstAddress: '0x...', // recipient on Base
    solver: '0x0000000000000000000000000000000000000000',
    data: '0x',
  },
  walletProvider,
  timeout: 120_000,
});

if (swapResult.ok) {
  console.log('Submitted. Hub tx:', swapResult.value.intentDeliveryInfo.dstTxHash);
} else {
  console.error('Swap failed:', swapResult.error);
}

ok means the intent was created, relayed to the hub, and the solver notified, not that it was filled. Poll sodax.swaps.getStatus({ intent_tx_hash: intentDeliveryInfo.dstTxHash }) until the status is SolverIntentStatusCode.SOLVED, which is the only success signal. The main quickstart has the full polling loop, including why NOT_FOUND is not terminal. A few things to know on Optimism:

ETH needs no approval. It is the native token. Swapping an ERC-20 (USDC, bnUSD, and the rest) needs an allowance first; see Approvals.
Amounts follow token.decimals. ETH uses 18; USDC and USDT use 6. Build every amount from the token you are sending.
Keep ETH for fees. The user pays execution gas plus an L1 data fee in ETH. When swapping ETH itself, do not send the whole balance.

Next steps

Swaps on Optimism: approvals, fees, manual orchestration.
Money Market on Optimism: supply and borrow with cross-network collateral.
Full API reference: Swaps in the SDK docs.

​1. Install

​2. Create an Optimism wallet provider

​3. Look up supported tokens

​4. Quote and swap

​Next steps

1. Install

2. Create an Optimism wallet provider

3. Look up supported tokens

4. Quote and swap

Next steps