Post-hook

Advanced orders / Hooks

Part 2/ Hooks/Post-hook

import type { Web3Provider } from '@ethersproject/providers'

import { Contract } from '@ethersproject/contracts'

import { OrderBookApi, UnsignedOrder, OrderKind, SigningScheme, OrderCreation } from '@cowprotocol/cow-sdk'

import { MetadataApi } from '@cowprotocol/app-data'

import { getSafeSdkAndKit } from './getSafeSdkAndKit'

import { SETTLEMENT_CONTRACT_ABI, SETTLEMENT_CONTRACT_ADDRESS } from './const'

export async function run(provider: Web3Provider): Promise<unknown> {

  const safeAddress = '<PUT_YOUR_SAFE_ADDRESS>'

  const appCode = '<YOUR_APP_CODE>'

  const environment = 'prod'

  // Slippage percent, it's 0 to 100

  const quote = { slippageBips: '50' }

  // "market" | "limit" | "liquidity"

  const orderClass = { orderClass: 'limit' }

  // Get chainId and account from the current provider

  const accounts = await provider.listAccounts()

  const account = accounts[0]

  const chainId = +(await provider.send('eth_chainId', []))

  // CoW Protocol OrderBookApi instance

  // It will be used to send the order to the order-book

  const orderBookApi = new OrderBookApi({ chainId })

  // Order creation requires meta information about the order

  const metadataApi = new MetadataApi()

  // Create the CoW Protocol Settlement contract instance

  const settlementContract = new Contract(SETTLEMENT_CONTRACT_ADDRESS, SETTLEMENT_CONTRACT_ABI)

  // Create the Safe SDK and Safe API Kit instances

  const { safeApiKit, safeSdk } = await getSafeSdkAndKit(chainId, provider, safeAddress)

  // The order

  // Pay attention to the `signingScheme` field that is set to `SigningScheme.PRESIGN`

  const defaultOrder: UnsignedOrder = {

    receiver: safeAddress,

    buyAmount: '650942340000000000000',

    buyToken: '0x91056D4A53E1faa1A84306D4deAEc71085394bC8',

    sellAmount: '100000000000000000',

    sellToken: '0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6',

    validTo: Math.round((Date.now() + 900_000) / 1000),

    appData: '0x',

    feeAmount: '0',

    kind: OrderKind.SELL,

    partiallyFillable: true,

    signingScheme: SigningScheme.PRESIGN,

  }

  // Generate the app-data document

  const appDataDoc = await metadataApi.generateAppDataDoc({

    appCode,

    environment,

    metadata: {

      quote,

      orderClass

    },

  })

  const { appDataHex, appDataContent } = await metadataApi.appDataToCid(appDataDoc)

  // Add all necessary fields to the order creation request

  const orderCreation: OrderCreation = {

    ...defaultOrder,

    from: safeAddress,

    signature: safeAddress,

    appData: appDataContent,

    appDataHash: appDataHex,

  }

  // Send order to CoW Protocol order-book

  const orderId = await orderBookApi.sendOrder(orderCreation)

  // Create the pre-signature transaction

  const presignCallData = settlementContract.interface.encodeFunctionData('setPreSignature', [

    orderId,

    true,

  ])

  const presignRawTx = {

    to: settlementContract.address,

    data: presignCallData,

    value: '0',

  }

  // Send pre-signature transaction to settlement contract

  // In this example we are using the Safe SDK, but you can use any other smart-contract wallet

  const safeTx = await safeSdk.createTransaction({safeTransactionData: presignRawTx})

  const signedSafeTx = await safeSdk.signTransaction(safeTx)

  const safeTxHash = await safeSdk.getTransactionHash(signedSafeTx)

  const senderSignature = signedSafeTx.signatures.get(account.toLowerCase())?.data || ''

  // Send the pre-signed transaction to the Safe

  await safeApiKit.proposeTransaction({

    safeAddress,

    safeTransactionData: signedSafeTx.data,

    safeTxHash,

    senderAddress: account,

    senderSignature,

  })

  return { orderId, safeTxHash, senderSignature }

}