How fees work
CoW Protocol does not charge fees as a separate transaction. Instead, fees are embedded in the trade itself — deducted from the amounts you’re already swapping. This means:
- Sell orders: fees reduce the buy amount you receive
- Buy orders: fees increase the sell amount you pay
There is no separate fee transfer, no gas token deduction, and no invoice. If you’re looking for fee data for accounting, see Retrieving fee data below.
Fee types
| Fee | What it covers | Applied to |
|---|
| Network costs | Gas fees for on-chain settlement | Sell token (always) |
| Protocol fee | CoW Protocol’s revenue (protocolFeeBps in quote) | Buy token (sell orders) / Sell token (buy orders) |
| Partner fee | Optional integrator fee (set via appData) | Buy token (sell orders) / Sell token (buy orders) |
| Slippage | Price movement tolerance (not a fee, but part of the pipeline) | Buy token (sell orders) / Sell token (buy orders) |
Fee pipeline
Fees are applied in a specific order, transforming the raw spot price into the final signed amounts:
Spot Price (beforeAllFees)
→ after Protocol Fee
→ after Network Costs
→ after Partner Fee
→ after Slippage = amounts you sign
Current protocol fee parameters
| Fee | Rate | Applies to |
|---|
| Surplus fee | 50% of surplus, capped at 0.98% of volume | Out-of-market limit orders |
| Quote improvement fee | 50% of improvement, capped at 0.98% of volume | Market orders (swaps) |
| Volume fee | 2 bps (standard) / 0.3 bps (correlated assets) | All orders |
Understanding the quote response
The /quote API response is the starting point for understanding fees:
{
"protocolFeeBps": "2",
"quote": {
"sellAmount": "99937516653569264",
"buyAmount": "191179999",
"feeAmount": "62483346430736",
"kind": "sell"
}
}
| Field | What it means |
|---|
sellAmount | Sell amount after network costs deducted |
buyAmount | Buy amount after network costs and protocol fee deducted |
feeAmount | Network costs in sell token units |
protocolFeeBps | Protocol fee in basis points (already reflected in buyAmount) |
feeAmount is the network cost only — not the total fee. The protocol fee is already embedded in buyAmount (sell orders) or sellAmount (buy orders).
What you sign vs. what you see
For a sell order, the amounts signed into the order are:
sellAmount = spot price amount (= quote.sellAmount + quote.feeAmount)buyAmount = minimum to receive after all fees and slippage
For a buy order:
sellAmount = maximum to pay after all fees and slippagebuyAmount = exact amount to receive (= spot price)
Retrieving fee data for accounting
On-chain, feeAmount is set to zero in the order struct. This confuses many integrators looking for fee data. The actual fees are embedded in the price difference between the quoted and executed amounts.
To get fee breakdowns for a filled order:
1. Query the order details
curl https://api.cow.fi/mainnet/api/v1/orders/{ORDER_UID}
executedSellAmount, executedBuyAmount, executedSellAmountBeforeFees, and executedFeeAmount — these reflect the actual settlement values.
2. Query the solver competition
curl https://api.cow.fi/mainnet/api/v1/solver_competition/by_tx_hash/{TX_HASH}
3. Use the CoW Explorer
Visit https://explorer.cow.fi/orders/{ORDER_UID} for a visual breakdown of the order’s fee components and settlement details.
For programmatic accounting, the TypeScript SDK and Python SDK provide typed access to order details including executed amounts and fees. 
