Quoting

CoW Protocol / Trading

Part 1/ Trading/Quoting

OK, so you're wanting to trade some tokens on CoW Protocol. Great! But before we do that, let's get a quote first so we know what we're getting into. We get quotes using the TradingSdk from @cowprotocol/cow-sdk.

Quote

As an example, let's get a quote for trading 1 wxDAI for COW on Gnosis chain. This is a simple swap (market order).

Which environment?

CoW Protocol supports multiple environments (e.g. mainnet, gnosis chain, sepolia, etc). We need to know which environment we want to trade on. For this tutorial, we'll use the Gnosis chain. Let's get the chainId for the connected wallet and compare it to the SupportedChainId enum from the @cowprotocol/cow-sdk library:

import type { PublicClient, WalletClient } from 'viem';
import { SupportedChainId } from '@cowprotocol/cow-sdk';

export async function run(setup: (chainId: SupportedChainId) => Promise<{ publicClient: PublicClient; walletClient: WalletClient }>): Promise<unknown> {

}

Setup the adapter

To use the TradingSdk with viem, we need to create a ViemAdapter:

import type { PublicClient, WalletClient } from 'viem';
import { SupportedChainId, TradingSdk } from '@cowprotocol/cow-sdk';
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter';

export async function run(setup: (chainId: SupportedChainId) => Promise<{ publicClient: PublicClient; walletClient: WalletClient }>): Promise<unknown> {
	// ...
	const adapter = new ViemAdapter({
		provider: publicClient,
		walletClient,
	});
	// ...
}

Instantiate the SDK

Next, we instantiate the TradingSdk with the adapter:

import type { PublicClient, WalletClient } from 'viem';
import { SupportedChainId, TradingSdk } from '@cowprotocol/cow-sdk';
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter';

export async function run(setup: (chainId: SupportedChainId) => Promise<{ publicClient: PublicClient; walletClient: WalletClient }>): Promise<unknown> {
	// ...
	const sdk = new TradingSdk({
		chainId: SupportedChainId.GNOSIS_CHAIN,
		appCode: 'CoW Swap',
	}, {}, adapter);
	// ...
}

We now have an instantiated TradingSdk that we can use to get quotes and trade on CoW Protocol.

Trade parameters

Now that we have an instantiated TradingSdk, we can get a quote. To do this, we need to specify trade parameters:

• the token we want to sell (the sellToken), in this case wxDAI
• the token we want to buy (the buyToken), in this case COW
• the amount of tokens we want to sell (the amount), in this case 1 wxDAI in atomic units (i.e. wei), which is 1000000000000000000
• the decimals for both tokens
• the order kind (SELL or BUY)

import type { PublicClient, WalletClient } from 'viem';
import { SupportedChainId, TradingSdk, OrderKind, TradeParameters } from '@cowprotocol/cow-sdk';
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter';

export async function run(setup: (chainId: SupportedChainId) => Promise<{ publicClient: PublicClient; walletClient: WalletClient }>): Promise<unknown> {
	// ...
	const sellToken = '0xe91d153e0b41518a2ce8dd3d7944fa863463a97d'; // wxDAI
	const buyToken = '0x177127622c4A00F3d409B75571e12cB3c8973d3c'; // COW

	const parameters: TradeParameters = {
		kind: OrderKind.SELL,
		sellToken,
		sellTokenDecimals: 18,
		buyToken,
		buyTokenDecimals: 18,
		amount: '1000000000000000000', // 1 wxDAI
	};
	// ...
}

Get the quote

Now that we have the trade parameters, we can get the quote using the TradingSdk:

import type { PublicClient, WalletClient } from 'viem';
import { SupportedChainId, TradingSdk, OrderKind, TradeParameters } from '@cowprotocol/cow-sdk';
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter';

export async function run(setup: (chainId: SupportedChainId) => Promise<{ publicClient: PublicClient; walletClient: WalletClient }>): Promise<unknown> {
	// ...
	const { quoteResults } = await sdk.getQuote(parameters);

	return quoteResults.amountsAndCosts;
}

Run the code

To run the code, we can press the "Run" button in the bottom right panel (the web container).

When running the script, we may be asked to connect a wallet. We can use Rabby for this.

1. Accept the connection request in Rabby
2. Press the "Run" button again
3. The output panel will display only QuoteResults.amountsAndCosts
4. Check browser console to see the whole QuoteResults

The QuoteResults object contains:

• quoteResponse: The raw quote response from the API containing order parameters
• tradeParameters: The trade parameters used for the quote
• amountsAndCosts: Calculated amounts including slippage and fees
• appDataInfo: Application-specific metadata
• orderToSign: The order data ready to be signed. Important! You don't have to sign exactly that object, sdk.getQuote() also returns postSwapOrderFromQuote function which will sing and send the order

The quote results provide all the information needed to proceed with signing and posting the order in subsequent tutorials.