Multi-Sig Order Flow

Placing orders from a Safe with multiple signers (multi-sig) requires coordinating signatures from threshold owners before the order can be submitted. This tutorial covers the complete flow using both PreSign and ERC-1271 approaches.

Overview

Safe multi-sig wallets can’t sign messages with a single key. Instead, you need to:

Propose the order and collect the required number of owner signatures
Submit the signed transaction to register the order on-chain (PreSign) or off-chain (ERC-1271)

Approach	How it works	Gas cost	When to use
PreSign	Execute a transaction calling `setPreSignature` on the settlement contract	~60k gas	Simple, reliable, works with any Safe configuration
ERC-1271	Submit an off-chain signature that the settlement contract verifies via `isValidSignature` on the Safe	No gas (off-chain)	Gas-efficient, but requires Safe’s ERC-1271 support

Most multi-sig integrations use PreSign because it’s simpler and doesn’t require handling Safe’s internal signature encoding. Use ERC-1271 when gas costs matter (e.g., frequent trading).

Prerequisites

A Safe deployed with 2+ owners and a threshold ≥ 2
The sell token approved for the CoW Protocol Vault Relayer from the Safe
Safe Protocol Kit installed: npm install @safe-global/protocol-kit

Method 1: PreSign (Recommended)

PreSign is the simplest approach — you create the order, then execute a Safe transaction to call setPreSignature on the settlement contract.

Create the order with PRESIGN signing scheme

import {
  SupportedChainId,
  OrderKind,
  TradingSdk,
  TradeParameters,
  SwapAdvancedSettings,
  SigningScheme,
} from '@cowprotocol/sdk-trading'
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter'
import { createPublicClient, http, privateKeyToAccount } from 'viem'
import { mainnet } from 'viem/chains'

const SAFE_ADDRESS = '0xYourSafeAddress'

const adapter = new ViemAdapter({
  provider: createPublicClient({
    chain: mainnet,
    transport: http('YOUR_RPC_URL'),
  }),
  // Use any Safe owner's key — this is for the SDK to create quotes
  signer: privateKeyToAccount('OWNER_1_PRIVATE_KEY' as `0x${string}`),
})

const sdk = new TradingSdk({
  chainId: SupportedChainId.MAINNET,
  appCode: 'my-multisig-app',
}, {}, adapter)

const parameters: TradeParameters = {
  kind: OrderKind.SELL,
  sellToken: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC
  sellTokenDecimals: 6,
  buyToken: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',  // WETH
  buyTokenDecimals: 18,
  amount: '10000000000', // 10,000 USDC
}

const advancedSettings: SwapAdvancedSettings = {
  quoteRequest: {
    from: SAFE_ADDRESS,                  // Quote from the Safe
    signingScheme: SigningScheme.PRESIGN, // Use PreSign for multi-sig
  },
}

const { orderId } = await sdk.postSwapOrder(parameters, advancedSettings)
console.log('Order created (pending PreSign):', orderId)

The order is now in the orderbook with status presignaturePending.

Build the PreSign Safe transaction

import Safe from '@safe-global/protocol-kit'
import { encodeFunctionData } from 'viem'

// Settlement contract ABI (just the setPreSignature function)
const SETTLEMENT_ABI = [{
  name: 'setPreSignature',
  type: 'function',
  inputs: [
    { name: 'orderUid', type: 'bytes' },
    { name: 'signed', type: 'bool' },
  ],
  outputs: [],
}]

const SETTLEMENT_CONTRACT = '0x9008D19f58AAbD9eD0D60971565AA8510560ab41'

// Encode the setPreSignature call
const callData = encodeFunctionData({
  abi: SETTLEMENT_ABI,
  functionName: 'setPreSignature',
  args: [orderId, true],
})

// Initialize Safe SDK (owner 1)
const safe = await Safe.init({
  provider: 'YOUR_RPC_URL',
  signer: 'OWNER_1_PRIVATE_KEY',
  safeAddress: SAFE_ADDRESS,
})

// Create the Safe transaction
const safeTx = await safe.createTransaction({
  transactions: [{
    to: SETTLEMENT_CONTRACT,
    value: '0',
    data: callData,
  }],
})

// Owner 1 signs
const signedTx = await safe.signTransaction(safeTx)
console.log('Owner 1 signed. Collecting more signatures...')

Collect additional owner signatures

Each additional owner signs the same transaction:

// Owner 2 initializes their Safe SDK instance
const safeOwner2 = await Safe.init({
  provider: 'YOUR_RPC_URL',
  signer: 'OWNER_2_PRIVATE_KEY',
  safeAddress: SAFE_ADDRESS,
})

// Owner 2 signs the same transaction
const fullySignedTx = await safeOwner2.signTransaction(signedTx)
console.log('Owner 2 signed. Threshold reached.')

In practice, Safe owners typically sign via the Safe Transaction Service or Safe UI rather than sharing private keys. The Safe SDK supports both approaches.

Execute the transaction

Once enough signatures are collected (≥ threshold), any owner can execute:

const result = await safe.executeTransaction(fullySignedTx)
console.log('PreSign tx hash:', result.hash)
console.log('Order is now Open and ready for execution!')

Using Safe Transaction Service

For production multi-sig flows, use the Safe Transaction Service to propose and collect signatures asynchronously:

import SafeApiKit from '@safe-global/api-kit'

const apiKit = new SafeApiKit({
  chainId: 1n,
})

// Owner 1: Propose the transaction
const safeTxHash = await safe.getTransactionHash(safeTx)
const signature = await safe.signHash(safeTxHash)

await apiKit.proposeTransaction({
  safeAddress: SAFE_ADDRESS,
  safeTransactionData: safeTx.data,
  safeTxHash,
  senderAddress: owner1Address,
  senderSignature: signature.data,
})

console.log('Transaction proposed. Other owners can sign via Safe UI.')

// Owner 2 (later): Confirm the transaction
await apiKit.confirmTransaction(safeTxHash, owner2Signature)

// Any owner: Execute when threshold is met
const pendingTxs = await apiKit.getPendingTransactions(SAFE_ADDRESS)
// Find the transaction and execute it

Method 2: ERC-1271 (Gas-Efficient)

ERC-1271 allows off-chain signing — no gas cost for the signature itself. The settlement contract calls isValidSignature on the Safe to verify.

import {
  SupportedChainId,
  OrderKind,
  TradingSdk,
  SigningScheme,
} from '@cowprotocol/sdk-trading'

const advancedSettings: SwapAdvancedSettings = {
  quoteRequest: {
    from: SAFE_ADDRESS,
    signingScheme: SigningScheme.EIP1271,
  },
}

const { orderId } = await sdk.postSwapOrder(parameters, advancedSettings)

ERC-1271 with Safe multi-sig requires encoding the combined Safe signatures in a specific format. This is more complex than PreSign. See the ERC-1271 Signing Guide for details on signature encoding.

Python SDK

The Python SDK’s swap_tokens function supports Safe multi-sig orders with the safe_address parameter:

from web3 import Account, Web3
from web3.types import Wei
from cowdao_cowpy.cow.swap import swap_tokens
from cowdao_cowpy.common.chains import Chain

account = Account.from_key("OWNER_PRIVATE_KEY")
safe_address = Web3.to_checksum_address("0xYourSafeAddress")

# This creates a PreSign order and returns the order UID
# You still need to execute the setPreSignature transaction from the Safe
completed_order = await swap_tokens(
    amount=Wei(10000 * 10**6),   # 10,000 USDC
    account=account,
    chain=Chain.MAINNET,
    sell_token=USDC_ADDRESS,
    buy_token=WETH_ADDRESS,
    safe_address=safe_address,   # Triggers PreSign signing scheme
)

print(f"Order UID: {completed_order.uid}")
print(f"Now execute setPreSignature from the Safe to activate the order")

Transaction Batching

For efficiency, you can batch the token approval and PreSign into a single Safe transaction using MultiSend:

// Batch: approve + setPreSignature in one Safe tx
const transactions = [
  {
    to: SELL_TOKEN,
    value: '0',
    data: encodeFunctionData({
      abi: ERC20_ABI,
      functionName: 'approve',
      args: [VAULT_RELAYER, sellAmount],
    }),
  },
  {
    to: SETTLEMENT_CONTRACT,
    value: '0',
    data: encodeFunctionData({
      abi: SETTLEMENT_ABI,
      functionName: 'setPreSignature',
      args: [orderId, true],
    }),
  },
]

const safeTx = await safe.createTransaction({ transactions })
// Sign and execute as above...

Order Lifecycle

1. Create order (signingScheme: PRESIGN)
   └── Status: presignaturePending

2. Propose Safe tx (setPreSignature)
   └── Owners sign via Safe UI or API

3. Execute Safe tx (threshold met)
   └── Status: open

4. Solver fills the order
   └── Status: fulfilled

Troubleshooting

Issue	Cause	Fix
Order stays `presignaturePending`	`setPreSignature` tx not executed	Ensure the Safe tx has enough signatures and execute it
`WrongOwner` error	`from` in quote doesn’t match Safe address	Set `from: SAFE_ADDRESS` in the quote request
Order expires before signing	Validity too short for multi-sig coordination	Use a longer `validTo` (e.g., 7 days)
Insufficient allowance	Vault Relayer not approved	Approve from the Safe before or batch with the PreSign tx

Next Steps

Smart Contract Wallets — PreSign details for the TypeScript SDK
ERC-1271 Signing — off-chain signing for custom contracts
Token Approvals — managing ERC-20 approvals

Overview

Trading Tutorials

Advanced

Hooks

Widget

Reference

Overview

Prerequisites

Method 1: PreSign (Recommended)

Using Safe Transaction Service

Method 2: ERC-1271 (Gas-Efficient)

Python SDK

Transaction Batching

Order Lifecycle

Troubleshooting

Next Steps

Overview

Trading Tutorials

Advanced

Hooks

Widget

Reference

​Overview

​Prerequisites

​Method 1: PreSign (Recommended)

​Using Safe Transaction Service

​Method 2: ERC-1271 (Gas-Efficient)

​Python SDK

​Transaction Batching

​Order Lifecycle

​Troubleshooting

​Next Steps

Overview

Prerequisites

Method 1: PreSign (Recommended)

Using Safe Transaction Service

Method 2: ERC-1271 (Gas-Efficient)

Python SDK

Transaction Batching

Order Lifecycle

Troubleshooting

Next Steps