diff --git a/packages/bridging/src/BridgingSdk/mock/bridgeRequestMocks.ts b/packages/bridging/src/BridgingSdk/mock/bridgeRequestMocks.ts
index 751534afb..8f1cd90cd 100644
--- a/packages/bridging/src/BridgingSdk/mock/bridgeRequestMocks.ts
+++ b/packages/bridging/src/BridgingSdk/mock/bridgeRequestMocks.ts
@@ -117,6 +117,10 @@ export const amountsAndCosts: QuoteAmountsAndCosts = {
       amount: BigInt('100000000'),
       bps: 100,
     },
+    protocolFee: {
+      amount: 0n,
+      bps: 0
+    }
   },
   beforeNetworkCosts: {
     sellAmount: BigInt('100000000'),
diff --git a/packages/order-book/package.json b/packages/order-book/package.json
index 3a759b89c..e55f28c5b 100644
--- a/packages/order-book/package.json
+++ b/packages/order-book/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@cowprotocol/sdk-order-book",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "description": "CowProtocol Order Book package",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",
@@ -20,7 +20,7 @@
     "test": "jest",
     "test:coverage": "jest --coverage --json --outputFile=jest.results.json && npx coveralls < ./coverage/lcov.info",
     "test:coverage:html": "jest --silent=false --coverage --coverageReporters html",
-    "swagger:codegen": "openapi --input https://raw.githubusercontent.com/cowprotocol/services/v2.291.0/crates/orderbook/openapi.yml --output src/generated --exportServices false --exportCore false",
+    "swagger:codegen": "openapi --input https://raw.githubusercontent.com/cowprotocol/services/dfb50cb4a103e8f949f5a7145beb6be63ef41c85/crates/orderbook/openapi.yml --output src/generated --exportServices false --exportCore false",
     "clean": "rm -rf .turbo && rm -rf node_modules && rm -rf dist",
     "typecheck": "tsc --noEmit",
     "prepublishOnly": "npm run build"
diff --git a/packages/order-book/src/quoteAmountsAndCostsUtils.test.ts b/packages/order-book/src/quoteAmountsAndCostsUtils.test.ts
index b815b1bb1..208f6176c 100644
--- a/packages/order-book/src/quoteAmountsAndCostsUtils.test.ts
+++ b/packages/order-book/src/quoteAmountsAndCostsUtils.test.ts
@@ -60,6 +60,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           slippagePercentBps: 0,
           partnerFeeBps: undefined,
+          protocolFeeBps: undefined,
         })
 
         expect(result.afterNetworkCosts.sellAmount.toString()).toBe(
@@ -74,6 +75,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           slippagePercentBps: 0,
           partnerFeeBps: undefined,
+          protocolFeeBps: undefined,
         })
 
         expect(result.beforeNetworkCosts.buyAmount.toString()).toBe(
@@ -99,6 +101,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           partnerFeeBps,
           slippagePercentBps: 0,
+          protocolFeeBps: undefined,
         })
 
         const buyAmountBeforeNetworkCosts =
@@ -120,6 +123,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           partnerFeeBps,
           slippagePercentBps: 0,
+          protocolFeeBps: undefined,
         })
 
         const partnerFeeAmount = Math.floor((+orderParams.sellAmount * partnerFeeBps) / 100 / 100)
@@ -141,6 +145,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           partnerFeeBps: undefined,
           slippagePercentBps,
+          protocolFeeBps: undefined,
         })
 
         const buyAmountAfterNetworkCosts = +orderParams.buyAmount
@@ -160,6 +165,7 @@ describe('Calculation of before/after fees amounts', () => {
           buyDecimals,
           partnerFeeBps: undefined,
           slippagePercentBps,
+          protocolFeeBps: undefined,
         })
 
         const sellAmountAfterNetworkCosts = +orderParams.sellAmount + +orderParams.feeAmount
diff --git a/packages/order-book/src/quoteAmountsAndCostsUtils.ts b/packages/order-book/src/quoteAmountsAndCostsUtils.ts
index 511864113..883f9a94d 100644
--- a/packages/order-book/src/quoteAmountsAndCostsUtils.ts
+++ b/packages/order-book/src/quoteAmountsAndCostsUtils.ts
@@ -7,6 +7,7 @@ export interface QuoteAmountsAndCostsParams {
   buyDecimals: number
   slippagePercentBps: number
   partnerFeeBps: number | undefined
+  protocolFeeBps: number | undefined
 }
 
 const ONE_HUNDRED_BPS = BigInt(100 * 100)
@@ -85,10 +86,10 @@ function _getQuoteAmountsWithCosts(params: {
 }
 
 function getQuoteAmountsWithPartnerFee(params: {
-  sellAmountAfterNetworkCosts: BigNumber
-  buyAmountAfterNetworkCosts: BigNumber
-  buyAmountBeforeNetworkCosts: BigNumber
-  sellAmountBeforeNetworkCosts: BigNumber
+  sellAmountAfterNetworkCosts: bigint
+  buyAmountAfterNetworkCosts: bigint
+  buyAmountBeforeNetworkCosts: bigint
+  sellAmountBeforeNetworkCosts: bigint
   isSell: boolean
   partnerFeeBps: number
 }) {
@@ -104,20 +105,20 @@ function getQuoteAmountsWithPartnerFee(params: {
   /**
    * Partner fee is always added on the surplus amount, for sell-orders it's buy amount, for buy-orders it's sell amount
    */
-  const surplusAmount = isSell ? buyAmountBeforeNetworkCosts.big : sellAmountBeforeNetworkCosts.big
-  const partnerFeeAmount = partnerFeeBps > 0 ? (surplusAmount * BigInt(partnerFeeBps)) / ONE_HUNDRED_BPS : BigInt(0)
+  const surplusAmount = isSell ? buyAmountBeforeNetworkCosts : sellAmountBeforeNetworkCosts
+  const partnerFeeAmount = partnerFeeBps > 0 ? (surplusAmount * BigInt(partnerFeeBps)) / ONE_HUNDRED_BPS : 0n
 
   /**
    * Partner fee is always added on the surplus token, for sell-orders it's buy token, for buy-orders it's sell token
    */
   const afterPartnerFees = isSell
     ? {
-        sellAmount: sellAmountAfterNetworkCosts.big,
-        buyAmount: buyAmountAfterNetworkCosts.big - partnerFeeAmount,
+        sellAmount: sellAmountAfterNetworkCosts,
+        buyAmount: buyAmountAfterNetworkCosts - partnerFeeAmount,
       }
     : {
-        sellAmount: sellAmountAfterNetworkCosts.big + partnerFeeAmount,
-        buyAmount: buyAmountAfterNetworkCosts.big,
+        sellAmount: sellAmountAfterNetworkCosts + partnerFeeAmount,
+        buyAmount: buyAmountAfterNetworkCosts,
       }
 
   return {
@@ -126,6 +127,40 @@ function getQuoteAmountsWithPartnerFee(params: {
   }
 }
 
+function getProtocolFeeAmount(params: {
+  sellAmountAfterNetworkCosts: bigint
+  buyAmountAfterNetworkCosts: bigint
+  networkCostAmount: bigint
+  isSell: boolean
+  protocolFeeBps: number
+}) {
+  const { sellAmountAfterNetworkCosts, buyAmountAfterNetworkCosts, networkCostAmount, isSell, protocolFeeBps } = params
+
+  if (protocolFeeBps <= 0) {
+    return 0n
+  }
+
+  const protocolFeeBpsBig = BigInt(protocolFeeBps)
+
+  if (isSell) {
+    /**
+     * SELL orders formula: protocolFeeInBuy = quoteBuyAmount * protocolFeeBps / (1 - protocolFeeBps)
+     *
+     * The buyAmountAfterNetworkCosts already includes the protocol fee (it was deducted from buyAmount by the API).
+     * We need to reconstruct the original buyAmount and calculate the fee amount.
+     */
+    const ONE_MINUS_PROTOCOL_FEE_BPS = ONE_HUNDRED_BPS - protocolFeeBpsBig
+    return (buyAmountAfterNetworkCosts * protocolFeeBpsBig) / ONE_MINUS_PROTOCOL_FEE_BPS
+  } else {
+    /**
+     * BUY orders formula: protocolFeeInSell = (quoteSellAmount + feeAmount) * proto colFeeBps  / (1 + protocolFeeBps)
+     */
+    const ONE_PLUS_PROTOCOL_FEE_BPS = ONE_HUNDRED_BPS + protocolFeeBpsBig
+    const sellAmountWithNetworkFee = sellAmountAfterNetworkCosts + networkCostAmount
+    return (sellAmountWithNetworkFee * protocolFeeBpsBig) / ONE_PLUS_PROTOCOL_FEE_BPS
+  }
+}
+
 function getQuoteAmountsWithSlippage(params: {
   afterPartnerFees: { sellAmount: bigint; buyAmount: bigint }
   isSell: boolean
@@ -155,6 +190,7 @@ function getQuoteAmountsWithSlippage(params: {
 export function getQuoteAmountsAndCosts(params: QuoteAmountsAndCostsParams): QuoteAmountsAndCosts {
   const { orderParams, sellDecimals, buyDecimals, slippagePercentBps } = params
   const partnerFeeBps = params.partnerFeeBps ?? 0
+  const protocolFeeBps = params.protocolFeeBps ?? 0
 
   // Get amounts including network costs
   const {
@@ -167,12 +203,21 @@ export function getQuoteAmountsAndCosts(params: QuoteAmountsAndCostsParams): Quo
     quotePrice,
   } = _getQuoteAmountsWithCosts({ sellDecimals, buyDecimals, orderParams })
 
+
+  const protocolFeeAmount = getProtocolFeeAmount({
+    sellAmountAfterNetworkCosts: sellAmountAfterNetworkCosts.big,
+    buyAmountAfterNetworkCosts: buyAmountAfterNetworkCosts.big,
+    networkCostAmount: networkCostAmount.big,
+    isSell,
+    protocolFeeBps,
+  })
+
   // Get amounts including partner fees
   const { afterPartnerFees, partnerFeeAmount } = getQuoteAmountsWithPartnerFee({
-    sellAmountAfterNetworkCosts,
-    buyAmountAfterNetworkCosts,
-    buyAmountBeforeNetworkCosts,
-    sellAmountBeforeNetworkCosts,
+    sellAmountAfterNetworkCosts: sellAmountAfterNetworkCosts.big,
+    buyAmountAfterNetworkCosts: buyAmountAfterNetworkCosts.big,
+    buyAmountBeforeNetworkCosts: buyAmountBeforeNetworkCosts.big,
+    sellAmountBeforeNetworkCosts: sellAmountBeforeNetworkCosts.big,
     isSell,
     partnerFeeBps,
   })
@@ -195,6 +240,10 @@ export function getQuoteAmountsAndCosts(params: QuoteAmountsAndCostsParams): Quo
         amount: partnerFeeAmount,
         bps: partnerFeeBps,
       },
+      protocolFee: {
+        amount: protocolFeeAmount,
+        bps: protocolFeeBps,
+      },
     },
     beforeNetworkCosts: {
       sellAmount: sellAmountBeforeNetworkCosts.big,
diff --git a/packages/order-book/src/types.ts b/packages/order-book/src/types.ts
index 32b1989fa..3cde5093d 100644
--- a/packages/order-book/src/types.ts
+++ b/packages/order-book/src/types.ts
@@ -21,6 +21,10 @@ export interface Costs<T> {
     amount: T
     bps: number
   }
+  protocolFee: {
+    amount: T
+    bps: number
+  }
 }
 
 /**
@@ -32,6 +36,7 @@ export interface Costs<T> {
  * The order of adding fees and costs is as follows:
  * 1. Network fee is always added to the sell amount
  * 2. Partner fee is added to the surplus amount (sell amount for sell-orders, buy amount for buy-orders)
+ * 3. Protocol fee --- need to clarify this one
  *
  * For sell-orders the partner fee is subtracted from the buy amount after network costs.
  * For buy-orders the partner fee is added on top of the sell amount after network costs.
diff --git a/packages/trading/src/getOrderToSign.ts b/packages/trading/src/getOrderToSign.ts
index 0da449753..332382ce8 100644
--- a/packages/trading/src/getOrderToSign.ts
+++ b/packages/trading/src/getOrderToSign.ts
@@ -18,10 +18,11 @@ interface OrderToSignParams {
   from: string
   networkCostsAmount?: string
   applyCostsSlippageAndFees?: boolean
+  protocolFeeBps?: number
 }
 
 export function getOrderToSign(
-  { chainId, from, networkCostsAmount = '0', isEthFlow, applyCostsSlippageAndFees = true }: OrderToSignParams,
+  { chainId, from, networkCostsAmount = '0', isEthFlow, applyCostsSlippageAndFees = true, protocolFeeBps }: OrderToSignParams,
   limitOrderParams: LimitTradeParameters,
   appDataKeccak256: string,
 ): UnsignedOrder {
@@ -63,6 +64,7 @@ export function getOrderToSign(
       orderParams,
       slippagePercentBps: slippageBps,
       partnerFeeBps: getPartnerFeeBps(partnerFee),
+      protocolFeeBps,
       sellDecimals: sellTokenDecimals,
       buyDecimals: buyTokenDecimals,
     })
diff --git a/packages/trading/src/getQuote.ts b/packages/trading/src/getQuote.ts
index 44bc17790..a10071fca 100644
--- a/packages/trading/src/getQuote.ts
+++ b/packages/trading/src/getQuote.ts
@@ -208,12 +208,13 @@ export async function getQuote(
     orderParams: quote.quote,
     slippagePercentBps: slippageBps,
     partnerFeeBps: getPartnerFeeBps(partnerFee),
+    protocolFeeBps: quote.protocolFeeBps ? Number(quote.protocolFeeBps) : undefined,
     sellDecimals: sellTokenDecimals,
     buyDecimals: buyTokenDecimals,
   })
 
   const orderToSign = getOrderToSign(
-    { chainId, from, networkCostsAmount: quote.quote.feeAmount, isEthFlow },
+    { chainId, from, networkCostsAmount: quote.quote.feeAmount, isEthFlow, protocolFeeBps: quote.protocolFeeBps ? Number(quote.protocolFeeBps) : undefined },
     swapParamsToLimitOrderParams(tradeParameters, quote),
     appDataInfo.appDataKeccak256,
   )
diff --git a/packages/trading/src/resolveSlippageSuggestion.ts b/packages/trading/src/resolveSlippageSuggestion.ts
index 7eddd844f..94b7fbaeb 100644
--- a/packages/trading/src/resolveSlippageSuggestion.ts
+++ b/packages/trading/src/resolveSlippageSuggestion.ts
@@ -36,6 +36,7 @@ export async function resolveSlippageSuggestion(
     orderParams: quote.quote,
     slippagePercentBps: 0,
     partnerFeeBps: getPartnerFeeBps(tradeParameters.partnerFee),
+    protocolFeeBps: quote.protocolFeeBps ? Number(quote.protocolFeeBps) : undefined,
     sellDecimals: tradeParameters.sellTokenDecimals,
     buyDecimals: tradeParameters.buyTokenDecimals,
   })
diff --git a/packages/trading/src/utils/misc.ts b/packages/trading/src/utils/misc.ts
index 6219a8376..43fb53ba3 100644
--- a/packages/trading/src/utils/misc.ts
+++ b/packages/trading/src/utils/misc.ts
@@ -33,7 +33,7 @@ export function mapQuoteAmountsAndCosts<T, R>(
   mapper: (value: T) => R,
 ): QuoteAmountsAndCosts<R> {
   const {
-    costs: { networkFee, partnerFee },
+    costs: { networkFee, partnerFee, protocolFee },
   } = value
 
   function serializeAmounts(value: { sellAmount: T; buyAmount: T }): { sellAmount: R; buyAmount: R } {
@@ -56,6 +56,10 @@ export function mapQuoteAmountsAndCosts<T, R>(
         ...partnerFee,
         amount: mapper(partnerFee.amount),
       },
+      protocolFee: {
+        ...protocolFee,
+        amount: mapper(protocolFee.amount),
+      },
     },
     beforeNetworkCosts: serializeAmounts(value.beforeNetworkCosts),
     afterNetworkCosts: serializeAmounts(value.afterNetworkCosts),