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Use this file to discover all available pages before exploring further.

This guide demonstrates how to perform a complete cross-chain swap between two EVM-compatible chains. We’ll walk through swapping USDT on Polygon to BNB on Binance Smart Chain.

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Overview

EVM to EVM swaps are the most common type of cross-chain swap. The process involves:
  1. Setting up the SDK with your credentials
  2. Getting a quote for the swap
  3. Generating secrets for the atomic swap
  4. Creating and submitting the order
  5. Monitoring and submitting secrets as escrows are deployed
  6. Tracking the order until completion

​
Complete Example

1

Install and Import Dependencies

First, install the SDK and import the required modules:
npm install @1inch/cross-chain-sdk web3

import {
    HashLock,
    NetworkEnum,
    OrderStatus,
    PresetEnum,
    PrivateKeyProviderConnector,
    SDK
} from '@1inch/cross-chain-sdk'
import Web3 from 'web3'
import { randomBytes } from 'node:crypto'
2

Initialize the SDK

Set up the SDK with your authentication key and blockchain provider:
const privateKey = '0x...' // Your wallet private key
const rpc = 'https://ethereum-rpc.publicnode.com'
const authKey = 'auth-key' // Get from https://portal.1inch.dev
const source = 'sdk-tutorial'

const web3 = new Web3(rpc)
const walletAddress = web3.eth.accounts.privateKeyToAccount(privateKey).address

const sdk = new SDK({
    url: 'https://api.1inch.com/fusion-plus',
    authKey,
    blockchainProvider: new PrivateKeyProviderConnector(privateKey, web3)
})
The blockchainProvider is only required for order creation. If you only need to query quotes or order status, you can omit it.
3

Get a Quote

Request a quote for your desired swap. This example swaps 10 USDT from Polygon to BNB on Binance:
// 10 USDT (Polygon) -> BNB (BSC)
const quote = await sdk.getQuote({
    amount: '10000000', // 10 USDT (6 decimals)
    srcChainId: NetworkEnum.POLYGON,
    dstChainId: NetworkEnum.BINANCE,
    enableEstimate: true,
    srcTokenAddress: '0xc2132d05d31c914a87c6611c10748aeb04b58e8f', // USDT on Polygon
    dstTokenAddress: '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee', // BNB (native)
    walletAddress
})
Use 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee as the token address for native assets like ETH, BNB, MATIC, etc.
4

Generate Secrets

Generate cryptographic secrets for the atomic swap. The number of secrets depends on the preset:
const preset = PresetEnum.fast

// Generate secrets based on the preset's required count
const secrets = Array.from({
    length: quote.presets[preset].secretsCount
}).map(() => '0x' + randomBytes(32).toString('hex'))

// Create hash lock for single or multiple fills
const hashLock =
    secrets.length === 1
        ? HashLock.forSingleFill(secrets[0])
        : HashLock.forMultipleFills(HashLock.getMerkleLeaves(secrets))

// Generate secret hashes for order creation
const secretHashes = secrets.map((s) => HashLock.hashSecret(s))
Keep your secrets secure! These are required to complete the swap. If you lose them, you won’t be able to claim your funds from the destination chain.
5

Create the Order

Create the cross-chain order with your parameters:
const { hash, quoteId, order } = await sdk.createOrder(quote, {
    walletAddress,
    hashLock,
    preset,
    source,
    secretHashes
})
console.log({ hash }, 'order created')
6

Submit the Order

Submit the order to the 1inch network:
const _orderInfo = await sdk.submitOrder(
    quote.srcChainId,
    order,
    quoteId,
    secretHashes
)
console.log({ hash }, 'order submitted')
Before submitting the order, ensure your wallet has sufficient allowance for the source token to the Limit Order Protocol contract on the source chain.
7

Monitor and Submit Secrets

Continuously monitor the order and submit secrets as escrows are deployed:
// Helper function for delays
async function sleep(ms: number): Promise<void> {
    return new Promise((resolve) => setTimeout(resolve, ms))
}

// Monitor and submit secrets
while (true) {
    const secretsToShare = await sdk.getReadyToAcceptSecretFills(hash)

    if (secretsToShare.fills.length) {
        for (const { idx } of secretsToShare.fills) {
            // It is your responsibility to verify escrow addresses before sharing secrets
            await sdk.submitSecret(hash, secrets[idx])
            console.log({ idx }, 'shared secret')
        }
    }

    // Check if order finished
    const { status } = await sdk.getOrderStatus(hash)

    if (
        status === OrderStatus.Executed ||
        status === OrderStatus.Expired ||
        status === OrderStatus.Refunded
    ) {
        break
    }

    await sleep(1000)
}

const statusResponse = await sdk.getOrderStatus(hash)
console.log(statusResponse)
Always verify escrow addresses and contract parameters before submitting secrets. The SDK returns the escrow details in the getReadyToAcceptSecretFills response.

​
Full Working Example

import {
    HashLock,
    NetworkEnum,
    OrderStatus,
    PresetEnum,
    PrivateKeyProviderConnector,
    SDK
} from '@1inch/cross-chain-sdk'
import Web3 from 'web3'
import { randomBytes } from 'node:crypto'

const privateKey = '0x...'
const rpc = 'https://ethereum-rpc.publicnode.com'
const authKey = 'auth-key'
const source = 'sdk-tutorial'

const web3 = new Web3(rpc)
const walletAddress = web3.eth.accounts.privateKeyToAccount(privateKey).address

const sdk = new SDK({
    url: 'https://api.1inch.com/fusion-plus',
    authKey,
    blockchainProvider: new PrivateKeyProviderConnector(privateKey, web3)
})

async function sleep(ms: number): Promise<void> {
    return new Promise((resolve) => setTimeout(resolve, ms))
}

async function main(): Promise<void> {
    // 10 USDT (Polygon) -> BNB (BSC)
    const quote = await sdk.getQuote({
        amount: '10000000',
        srcChainId: NetworkEnum.POLYGON,
        dstChainId: NetworkEnum.BINANCE,
        enableEstimate: true,
        srcTokenAddress: '0xc2132d05d31c914a87c6611c10748aeb04b58e8f',
        dstTokenAddress: '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
        walletAddress
    })

    const preset = PresetEnum.fast

    const secrets = Array.from({
        length: quote.presets[preset].secretsCount
    }).map(() => '0x' + randomBytes(32).toString('hex'))

    const hashLock =
        secrets.length === 1
            ? HashLock.forSingleFill(secrets[0])
            : HashLock.forMultipleFills(HashLock.getMerkleLeaves(secrets))

    const secretHashes = secrets.map((s) => HashLock.hashSecret(s))

    const { hash, quoteId, order } = await sdk.createOrder(quote, {
        walletAddress,
        hashLock,
        preset,
        source,
        secretHashes
    })
    console.log({ hash }, 'order created')

    const _orderInfo = await sdk.submitOrder(
        quote.srcChainId,
        order,
        quoteId,
        secretHashes
    )
    console.log({ hash }, 'order submitted')

    while (true) {
        const secretsToShare = await sdk.getReadyToAcceptSecretFills(hash)

        if (secretsToShare.fills.length) {
            for (const { idx } of secretsToShare.fills) {
                await sdk.submitSecret(hash, secrets[idx])
                console.log({ idx }, 'shared secret')
            }
        }

        const { status } = await sdk.getOrderStatus(hash)

        if (
            status === OrderStatus.Executed ||
            status === OrderStatus.Expired ||
            status === OrderStatus.Refunded
        ) {
            break
        }

        await sleep(1000)
    }

    const statusResponse = await sdk.getOrderStatus(hash)
    console.log(statusResponse)
}

main()

​
Order Presets

The SDK offers different presets that balance speed, cost, and reliability:
  • fast: Optimized for speed with higher fees
  • medium: Balanced speed and cost (recommended)
  • slow: Lower fees but takes longer
You can also use quote.recommendedPreset to let the SDK choose the best preset for your swap.

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Next Steps