Orders
CoW Protocol uses an intent-based order system where users express trading preferences off-chain, and solvers compete to find the best execution.
Order Structure
Orders contain 12 parameters defining trading intent:
| Parameter | Type | Description |
|---|
sellToken | address | Token to sell (ERC20) |
buyToken | address | Token to buy (ERC20) |
sellAmount | uint256 | Amount of sell token |
buyAmount | uint256 | Minimum/maximum amount of buy token |
validTo | uint32 | Order expiration timestamp |
appData | bytes32 | Application-specific metadata |
feeAmount | uint256 | Fee amount in sell token |
kind | bytes32 | Order kind (sell or buy) |
partiallyFillable | bool | Whether the order can be partially filled |
sellTokenBalance | bytes32 | Source of sell tokens |
buyTokenBalance | bytes32 | Destination of buy tokens |
receiver | address | Recipient of bought tokens |
Order Types
Sell Orders
Specify an exact amount to sell with a minimum buy amount guaranteed:
sellAmount is the exact amount of sell tokens to exchangebuyAmount is the minimum acceptable amount of buy tokens
Buy Orders
Specify an exact amount to buy with a maximum sell amount capped:
buyAmount is the exact amount of buy tokens to receivesellAmount is the maximum amount of sell tokens to spend
Order UID
Each order receives a unique 56-byte UID combining:
- Order digest (32 bytes) - EIP-712 hash of the order
- Owner address (20 bytes) - The order creator
- Validity timestamp (4 bytes) - Expiration time
EIP-712 Signing
Orders use typed EIP-712 signatures enabling hardware wallet support. The protocol hashes order data with a domain separator to create an order digest.
bytes32 orderDigest = keccak256(
abi.encodePacked(
"\x19\x01",
domainSeparator,
orderStructHash
)
);
Signature Schemes
CoW Protocol supports four signing methods:
| Scheme | Use Case |
|---|
| EIP-712 | Standard typed data signing (recommended) |
| eth_sign | Legacy signing for compatibility |
| EIP-1271 | Smart contract wallet validation (e.g., Gnosis Safe) |
| PreSign | On-chain pre-authorization |
Balance Sources
Users can source tokens from three different balance types:
- ERC20 - Standard ERC20 token balances
- External - Balancer Vault external balances
- Internal - Balancer Vault internal balances
Order Validation
During settlement, five checks occur:
- Signature validity - Verifies the order was signed by the owner
- Expiration status - Ensures
validTo has not passed
- Limit price compliance - Checks that clearing prices respect order limits
- Fill amount verification - Prevents overfilling
- Sufficient balance - Confirms the user has enough tokens
Order Lifecycle
- Created - Order signed off-chain
- Submitted - Order sent to the order pool
- Filled - Order completely executed
- PartiallyFilled - Order partially executed (if
partiallyFillable is true)
- Expired - Order
validTo timestamp has passed
- Cancelled - Order invalidated by the owner
Last modified on March 4, 2026
