Signing 0x Orders
In this guide, we discuss how to use @0x/protocol-utils or ethers.js to sign 0x Orders
At the heart of 0x Orders are signatures that authorize the 0x smart contracts to perform swaps on behalf of signers.
Whether you are posting Limit Orders to the 0x Orderbook API andProviding RFQ liquidity to 0x API- you will need to sign a 0x order.
When you sign a 0x Order, you are signing the Order Hash. See Generating 0x Order Hashes on how to derive your order's hash.
Because the hash is generated over all the fields of the order (as well as the chain ID and verifying contract), signing the hash is as good as signing all the fields of the order itself.
The 0x smart contracts supports 2 types of signatures:
EthSign- this is the standard way of signing messages: adding an EIP-191 prefix to the bytes you are about to sign and usingeth_sign(or equivalent) to generate the signature. In the 0x ecosystem, these signatures havesignatureTypeof3EIP712- this signing method is optimized for wallets to show human readable data before signing. It useseth_signTypedData(or equivalent) to generate a signature. In the 0x ecosystem, these signatures havesignatureTypeof2
yarn add @0x/protocol-utils
Using this library to sign orders:
const protocolUtils = require('@0x/protocol-utils');
const order = new protocolUtils.LimitOrder({ // or protocolUtils.RfqOrder
makerToken: '0x6B175474E89094C44Da98b954EedeAC495271d0F', // DAI
takerToken: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2', // WETH
... // Other fields
})
// Generate an EthSign signature with a provider.
const signature = await order.getSignatureWithProviderAsync(
web3.currentProvider,
);
// Generate an EthSign signature with a private key.
const signature = await order.getSignatureWithKey(
'0x123456...', // Maker's 32-byte private key, in hex.
);
// Generate an EIP712 signature with a provider (e.g., metamask).
const signature = await order.getSignatureWithProviderAsync(
web3.currentProvider,
utils.SignatureType.EIP712,
);
// Generate an EIP712 signature with a private key.
const signature = await order.getSignatureWithKey(
'0x123456...', // Maker's 32-byte private key, in hex.
utils.SignatureType.EIP712,
);
Ethers.js is a popular open source library that makes it easy to interact with EVM based chains. We can also use Ethers.js to sign orders.
Assuming you have the order hash, you may do the following:
const { ethers } = require("ethers");
// 0x orderHash
const orderHash = "0x41dbae71b2e4b42fbb2c66cd9d3f2921560c6d79d4452a4f9dd1e3940b88d2ef";
// Get signer
const provider = new ethers.providers.JsonRpcProvider(/* constructor params */);
const signer = provider.getSigner(/* address */);
// Get signature
const rawSignature = await signer.signMessage(ethers.utils.arrayify(orderHash));
const { v, r, s } = ethers.utils.splitSignature(rawSignature);
const signature = {
v,
r,
s,
signatureType: 3
};
Last modified 6mo ago