CoW Swap's trading process has one fundamental difference from most DEXs: you are not signing an on-chain transaction. Instead, you sign an off-chain order intent. This means that after you click "Confirm," your funds do not move immediately. The order enters a batch auction where solvers compete until someone finds a suitable price and route to settle it on-chain.
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Once you understand this, the logic behind approvals, order signing, and settlement verification becomes clear.
Approvals: Know Who You Are Approving
The first time you trade a specific token on CoW Swap, you need to approve it. The approval target is the Vault Relayer contract (GPv2VaultRelayer), not the settlement contract. The Vault Relayer is responsible for pulling your sell tokens from your wallet to the settlement contract when your order is executed.
CoW Swap requests "unlimited" approval by default. The benefit is that you do not need to approve the same token again for future trades, saving gas. The risk is that if the Vault Relayer contract has a vulnerability, or if your wallet's private key is compromised, an attacker could theoretically drain your entire balance of that token.
If you do not plan to trade the same token frequently, or if you are concerned about unlimited approvals, you can change the approval amount in your wallet's transaction prompt to the exact amount needed for a single trade. You will need to approve again before each trade, which costs extra gas, but it limits your exposure. After approving, you can use revoke.cash to view and revoke existing approvals.
A useful feature to know: some tokens support gasless approvals. Tokens like USDC, DAI, and COW support EIP-2612 permit signatures, which allow you to approve without holding ETH for gas. CoW Swap automatically detects and guides you through this process. However, this feature does not support smart contract wallets (like Safe).
Signing Orders: Off-chain Signatures Have No On-chain Fallback
After the approval is confirmed, clicking Swap will bring up a confirmation screen where you can review the quote, slippage tolerance, and other details. Once you confirm, your wallet will prompt you to sign the order.
This signature is off-chain. You are signing a message that says, "I am willing to sell X for at least Y under these conditions." Once the order parameters are signed and submitted to the order book API, they cannot be changed. If you made a mistake, you must cancel the order and create a new one.
The signing method depends on your wallet type. Regular EOA wallets typically use EIP-712 structured signing, and the wallet interface will display the key order details (what you are selling, what you are buying, the expiration time, etc.). If you are using a smart contract wallet like Safe, the signing process uses the PreSign or ERC-1271 path, which is different from a standard wallet.
A critical parameter to check before signing: the receiver address. CoW Swap's official documentation warns that fake CoW Swap websites exist. These sites secretly change the receiver address to the attacker's address, causing your bought tokens to be sent to them. Normally, this should show as 0x0...0 or your own signing address. If you did not manually set a custom receiving address, but the interface shows an unfamiliar address, do not sign.
Settlement Verification: Check the Off-chain Order Book and On-chain Settlement Separately
After you sign and submit your order, it enters CoW Protocol's off-chain order book and waits for solvers to execute it. You can check the order status by clicking your wallet address in the top right corner of the CoW Swap interface to open the activity panel.
There are several possible order statuses. It is important to understand the difference:
Open: The order is in the order book, waiting for a solver to match it.
Filled: The order has been executed and the funds have been transferred. You can click on this status to view the corresponding on-chain settlement transaction.
Partially Filled: Partial fill. Limit orders are partially fillable by default. A portion of the order may be filled first, while the remaining small balance might not be executed by solvers because it is not enough to cover the settlement gas costs.
Expired: The order was not executed before its expiration time and is now invalid.
Cancelled: You manually cancelled the order.
The most direct way to verify is to look up the order ID on CoW Explorer. CoW Explorer is CoW Protocol's official block explorer interface. You can search by order ID or your wallet address. The order details page will show the execution price, the actual filled amount, and the corresponding settlement transaction hash (which you can check on Etherscan).
An easy-to-miss distinction: An order showing "Filled" does not mean the money is in your wallet yet. The real confirmation is that the settlement transaction is confirmed on-chain and the bought tokens have been transferred to your address. In the order details on CoW Explorer, there is a "To" field that shows the address receiving the bought tokens. If this address is your own wallet, the funds will arrive once the settlement is confirmed.
Common Reasons Why Limit Orders Do Not Fill
If you placed a limit order and the market price has reached your price but the order is not filling, the most common reason is that the fees have not been covered yet. CoW Protocol's limit orders do not charge fees upfront. Instead, they execute only when the market price exceeds your limit price by enough to cover the settlement gas costs. The "Executes At" column in the order panel shows the actual trigger price including fees, which is more intuitive than your limit price.
Another possible reason is the fill-or-kill setting. Limit orders are partially fillable by default. If you changed this setting to fill-or-kill, the order must be filled completely in one go. For small amounts or illiquid trading pairs, it might be difficult to find a solver willing to match the entire amount at once.
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References
- CoW Protocol Documentation·Market orders (swap), no update date indicated; accessed: 2026-10-03.
- revoke.cash·Official homepage, no update date indicated; accessed: 2026-10-03.
- 登链社区·深入探讨 CoW 协议签名方法 (第一部分), published or updated: 2026-02-26; accessed: 2026-10-03.
- CoW Protocol Documentation·By order, no update date indicated; accessed: 2026-10-03.
- CoW Protocol Documentation·Viewing orders, no update date indicated; accessed: 2026-10-03.
- CoW DAO·Why Your CoW Swap Limit Order Hasn't Filled Yet, published or updated: 2026-09-11; accessed: 2026-10-03.
