diff --git a/src/api/orders/order-api.spec.ts b/src/api/orders/order-api.spec.ts
index 6ca7795..3c16563 100644
--- a/src/api/orders/order-api.spec.ts
+++ b/src/api/orders/order-api.spec.ts
@@ -102,7 +102,7 @@ describe(__filename, () => {
 
             expect(response).toEqual(expected)
             expect(httpProvider.get).toHaveBeenLastCalledWith(
-                `${url}/orders/v1.0/1/order/active/?page=1&limit=2`
+                `${url}/orders/v2.0/1/order/active/?page=1&limit=2`
             )
         })
 
@@ -175,7 +175,7 @@ describe(__filename, () => {
 
             expect(response).toEqual(expected)
             expect(httpProvider.get).toHaveBeenLastCalledWith(
-                `${url}/orders/v1.0/1/order/active/?`
+                `${url}/orders/v2.0/1/order/active/?`
             )
         })
     })
@@ -225,7 +225,7 @@ describe(__filename, () => {
 
             expect(response).toEqual(expected)
             expect(httpProvider.get).toHaveBeenLastCalledWith(
-                `${url}/orders/v1.0/1/order/status/${orderHash}`
+                `${url}/orders/v2.0/1/order/status/${orderHash}`
             )
         })
 
@@ -377,7 +377,7 @@ describe(__filename, () => {
 
             expect(response).toEqual(expected)
             expect(httpProvider.get).toHaveBeenLastCalledWith(
-                `${url}/orders/v1.0/1/order/maker/${address}/?limit=1&page=1`
+                `${url}/orders/v2.0/1/order/maker/${address}/?limit=1&page=1`
             )
         })
 
@@ -433,7 +433,7 @@ describe(__filename, () => {
 
             expect(response).toEqual(expected)
             expect(httpProvider.get).toHaveBeenLastCalledWith(
-                `${url}/orders/v1.0/1/order/maker/${address}/?`
+                `${url}/orders/v2.0/1/order/maker/${address}/?`
             )
         })
 
diff --git a/src/api/orders/orders.api.ts b/src/api/orders/orders.api.ts
index 8e4181c..ea4284a 100644
--- a/src/api/orders/orders.api.ts
+++ b/src/api/orders/orders.api.ts
@@ -13,6 +13,8 @@ import {AxiosProviderConnector, HttpProviderConnector} from '../../connector'
 import {concatQueryParams} from '../params'
 
 export class OrdersApi {
+    private static Version = 'v2.0'
+
     constructor(
         private readonly config: OrdersApiConfig,
         private readonly httpClient: HttpProviderConnector
@@ -37,7 +39,7 @@ export class OrdersApi {
         }
 
         const queryParams = concatQueryParams(params.build())
-        const url = `${this.config.url}/v1.0/${this.config.network}/order/active/${queryParams}`
+        const url = `${this.config.url}/${OrdersApi.Version}/${this.config.network}/order/active/${queryParams}`
 
         return this.httpClient.get<ActiveOrdersResponse>(url)
     }
@@ -51,7 +53,7 @@ export class OrdersApi {
             throw new Error(err)
         }
 
-        const url = `${this.config.url}/v1.0/${this.config.network}/order/status/${params.orderHash}`
+        const url = `${this.config.url}/${OrdersApi.Version}/${this.config.network}/order/status/${params.orderHash}`
 
         return this.httpClient.get<OrderStatusResponse>(url)
     }
@@ -66,7 +68,7 @@ export class OrdersApi {
         }
 
         const queryParams = concatQueryParams(params.buildQueryParams())
-        const url = `${this.config.url}/v1.0/${this.config.network}/order/maker/${params.address}/${queryParams}`
+        const url = `${this.config.url}/${OrdersApi.Version}/${this.config.network}/order/maker/${params.address}/${queryParams}`
 
         return this.httpClient.get(url)
     }
diff --git a/src/api/quoter/quote/quote.ts b/src/api/quoter/quote/quote.ts
index f60cc7a..9c82540 100644
--- a/src/api/quoter/quote/quote.ts
+++ b/src/api/quoter/quote/quote.ts
@@ -1,4 +1,5 @@
-import {Address} from '@1inch/limit-order-sdk'
+import {Address, randBigInt} from '@1inch/limit-order-sdk'
+import {UINT_40_MAX} from '@1inch/byte-utils'
 import {FusionOrderParams} from './order-params'
 import {FusionOrderParamsData} from './types'
 import {Cost, PresetEnum, QuoterResponse} from '../types'
@@ -76,6 +77,16 @@ export class Quote {
             params.delayAuctionStartTimeBy
         )
 
+        const allowPartialFills =
+            paramsData?.allowPartialFills ?? preset.allowPartialFills
+        const allowMultipleFills =
+            paramsData?.allowMultipleFills ?? preset.allowMultipleFills
+        const isNonceRequired = !allowPartialFills || !allowMultipleFills
+
+        const nonce = isNonceRequired
+            ? params.nonce ?? randBigInt(UINT_40_MAX)
+            : params.nonce
+
         return FusionOrder.new(
             this.settlementAddress,
             {
@@ -103,15 +114,13 @@ export class Quote {
                 )
             },
             {
-                nonce: params.nonce,
+                nonce,
                 unwrapWETH: this.params.toTokenAddress.isNative(),
                 permit: params.permit
                     ? this.params.fromTokenAddress + params.permit.substring(2)
                     : undefined,
-                allowPartialFills:
-                    paramsData?.allowPartialFills ?? preset.allowPartialFills,
-                allowMultipleFills:
-                    paramsData?.allowMultipleFills ?? preset.allowMultipleFills,
+                allowPartialFills,
+                allowMultipleFills,
                 orderExpirationDelay: paramsData?.orderExpirationDelay
             }
         )
diff --git a/src/api/quoter/quoter.api.spec.ts b/src/api/quoter/quoter.api.spec.ts
index b09770c..7e2bb8d 100644
--- a/src/api/quoter/quoter.api.spec.ts
+++ b/src/api/quoter/quoter.api.spec.ts
@@ -135,7 +135,7 @@ describe('Quoter API', () => {
 
         expect(res).toStrictEqual(QuoterResponseMock)
         expect(httpProvider.get).toHaveBeenCalledWith(
-            'https://test.com/quoter/v1.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&source=sdk'
+            'https://test.com/quoter/v2.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&source=sdk'
         )
     })
 
@@ -161,7 +161,7 @@ describe('Quoter API', () => {
         const res = await quoter.getQuote(params)
         expect(res).toStrictEqual(QuoterResponseMock)
         expect(httpProvider.get).toHaveBeenCalledWith(
-            'https://test.com/quoter/v1.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&fee=1&source=0x6b175474e89094c44da98b954eedeac495271d0f'
+            'https://test.com/quoter/v2.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&fee=1&source=0x6b175474e89094c44da98b954eedeac495271d0f'
         )
     })
 
@@ -199,7 +199,7 @@ describe('Quoter API', () => {
         const res = await quoter.getQuoteWithCustomPreset(params, body)
         expect(res).toStrictEqual(QuoterResponseMock)
         expect(httpProvider.post).toHaveBeenCalledWith(
-            'https://test.com/quoter/v1.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&fee=1&source=0x6b175474e89094c44da98b954eedeac495271d0f',
+            'https://test.com/quoter/v2.0/1/quote/receive/?fromTokenAddress=0x6b175474e89094c44da98b954eedeac495271d0f&toTokenAddress=0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2&amount=1000000000000000000000&walletAddress=0x00000000219ab540356cbb839cbe05303d7705fa&fee=1&source=0x6b175474e89094c44da98b954eedeac495271d0f',
             body.build()
         )
     })
diff --git a/src/api/quoter/quoter.api.ts b/src/api/quoter/quoter.api.ts
index 17e2521..6dfd09e 100644
--- a/src/api/quoter/quoter.api.ts
+++ b/src/api/quoter/quoter.api.ts
@@ -6,6 +6,8 @@ import {concatQueryParams} from '../params'
 import {AxiosProviderConnector, HttpProviderConnector} from '../../connector'
 
 export class QuoterApi {
+    private static Version = 'v2.0'
+
     constructor(
         private readonly config: QuoterApiConfig,
         private readonly httpClient: HttpProviderConnector
@@ -22,7 +24,7 @@ export class QuoterApi {
 
     async getQuote(params: QuoterRequest): Promise<Quote> {
         const queryParams = concatQueryParams(params.build())
-        const url = `${this.config.url}/v1.0/${this.config.network}/quote/receive/${queryParams}`
+        const url = `${this.config.url}/${QuoterApi.Version}/${this.config.network}/quote/receive/${queryParams}`
 
         const res = await this.httpClient.get<QuoterResponse>(url)
 
@@ -41,7 +43,7 @@ export class QuoterApi {
 
         const queryParams = concatQueryParams(params.build())
         const bodyParams = body.build()
-        const url = `${this.config.url}/v1.0/${this.config.network}/quote/receive/${queryParams}`
+        const url = `${this.config.url}/${QuoterApi.Version}/${this.config.network}/quote/receive/${queryParams}`
 
         const res = await this.httpClient.post<QuoterResponse>(url, bodyParams)
 
diff --git a/src/api/relayer/relayer.api.spec.ts b/src/api/relayer/relayer.api.spec.ts
index e0e36f5..93bf407 100644
--- a/src/api/relayer/relayer.api.spec.ts
+++ b/src/api/relayer/relayer.api.spec.ts
@@ -34,7 +34,8 @@ describe('Relayer API', () => {
                 makerTraits: '0'
             },
             signature: '0x123signature-here789',
-            quoteId: '9a43c86d-f3d7-45b9-8cb6-803d2bdfa08b'
+            quoteId: '9a43c86d-f3d7-45b9-8cb6-803d2bdfa08b',
+            extension: '0x'
         }
 
         const params = RelayerRequest.new(orderData)
@@ -42,7 +43,7 @@ describe('Relayer API', () => {
         await quoter.submit(params)
 
         expect(httpProvider.post).toHaveBeenCalledWith(
-            'https://test.com/relayer/v1.0/1/order/submit',
+            'https://test.com/relayer/v2.0/1/order/submit',
             orderData
         )
     })
@@ -68,7 +69,8 @@ describe('Relayer API', () => {
                 makerTraits: '0'
             },
             signature: '0x123signature-here789',
-            quoteId: '9a43c86d-f3d7-45b9-8cb6-803d2bdfa08b'
+            quoteId: '9a43c86d-f3d7-45b9-8cb6-803d2bdfa08b',
+            extension: '0x'
         }
 
         const orderData2: RelayerRequestParams = {
@@ -83,7 +85,8 @@ describe('Relayer API', () => {
                 makerTraits: '0'
             },
             signature: '0x123signature-2-here789',
-            quoteId: '1a36c861-ffd7-45b9-1cb6-403d3bdfa084'
+            quoteId: '1a36c861-ffd7-45b9-1cb6-403d3bdfa084',
+            extension: '0x'
         }
 
         const params = [
@@ -94,7 +97,7 @@ describe('Relayer API', () => {
         await quoter.submitBatch(params)
 
         expect(httpProvider.post).toHaveBeenCalledWith(
-            'https://test.com/relayer/v1.0/1/order/submit/many',
+            'https://test.com/relayer/v2.0/1/order/submit/many',
             params
         )
     })
diff --git a/src/api/relayer/relayer.api.ts b/src/api/relayer/relayer.api.ts
index c43b029..0ea3824 100644
--- a/src/api/relayer/relayer.api.ts
+++ b/src/api/relayer/relayer.api.ts
@@ -3,6 +3,8 @@ import {RelayerApiConfig} from './types'
 import {AxiosProviderConnector, HttpProviderConnector} from '../../connector'
 
 export class RelayerApi {
+    private static Version = 'v2.0'
+
     constructor(
         private readonly config: RelayerApiConfig,
         private readonly httpClient: HttpProviderConnector
@@ -18,13 +20,13 @@ export class RelayerApi {
     }
 
     submit(params: RelayerRequest): Promise<void> {
-        const url = `${this.config.url}/v1.0/${this.config.network}/order/submit`
+        const url = `${this.config.url}/${RelayerApi.Version}/${this.config.network}/order/submit`
 
         return this.httpClient.post(url, params)
     }
 
     submitBatch(params: RelayerRequest[]): Promise<void> {
-        const url = `${this.config.url}/v1.0/${this.config.network}/order/submit/many`
+        const url = `${this.config.url}/${RelayerApi.Version}/${this.config.network}/order/submit/many`
 
         return this.httpClient.post(url, params)
     }
diff --git a/src/api/relayer/relayer.request.ts b/src/api/relayer/relayer.request.ts
index 2b5d6e2..b2d02a6 100644
--- a/src/api/relayer/relayer.request.ts
+++ b/src/api/relayer/relayer.request.ts
@@ -8,10 +8,13 @@ export class RelayerRequest {
 
     public readonly quoteId: string
 
+    public readonly extension: string
+
     constructor(params: RelayerRequestParams) {
         this.order = params.order
         this.signature = params.signature
         this.quoteId = params.quoteId
+        this.extension = params.extension
     }
 
     static new(params: RelayerRequestParams): RelayerRequest {
@@ -22,7 +25,8 @@ export class RelayerRequest {
         return {
             order: this.order,
             signature: this.signature,
-            quoteId: this.quoteId
+            quoteId: this.quoteId,
+            extension: this.extension
         }
     }
 }
diff --git a/src/api/relayer/types.ts b/src/api/relayer/types.ts
index c577559..bc91522 100644
--- a/src/api/relayer/types.ts
+++ b/src/api/relayer/types.ts
@@ -5,6 +5,7 @@ export type RelayerRequestParams = {
     order: LimitOrderV4Struct
     signature: string
     quoteId: string
+    extension: string
 }
 
 export type RelayerApiConfig = {
diff --git a/src/fusion-order/fusion-order.ts b/src/fusion-order/fusion-order.ts
index 543d119..1cfff5b 100644
--- a/src/fusion-order/fusion-order.ts
+++ b/src/fusion-order/fusion-order.ts
@@ -47,7 +47,7 @@ export class FusionOrder {
         extra: {
             unwrapWETH?: boolean
             /**
-             * Required if `allowPartialFills` is false
+             * Required if `allowPartialFills` or `allowMultipleFills` is false
              */
             nonce?: bigint
             /**
@@ -230,7 +230,8 @@ export class FusionOrder {
         extra?: {
             unwrapWETH?: boolean
             /**
-             * Required if `allowPartialFills` is false
+             * Required if `allowPartialFills` or `allowMultipleFills` is false
+             * Max size is 40bit
              */
             nonce?: bigint
             permit?: string
diff --git a/src/sdk/sdk.ts b/src/sdk/sdk.ts
index e63db46..55b11a2 100644
--- a/src/sdk/sdk.ts
+++ b/src/sdk/sdk.ts
@@ -142,7 +142,8 @@ export class FusionSDK {
         const relayerRequest = RelayerRequest.new({
             order: orderStruct,
             signature,
-            quoteId
+            quoteId,
+            extension: order.extension.encode()
         })
 
         await this.api.submitOrder(relayerRequest)
@@ -151,7 +152,8 @@ export class FusionSDK {
             order: orderStruct,
             signature,
             quoteId,
-            orderHash: order.getOrderHash(this.config.network)
+            orderHash: order.getOrderHash(this.config.network),
+            extension: relayerRequest.extension
         }
     }
 
diff --git a/src/sdk/types.ts b/src/sdk/types.ts
index 90da265..36d84aa 100644
--- a/src/sdk/types.ts
+++ b/src/sdk/types.ts
@@ -63,6 +63,7 @@ export type OrderInfo = {
     signature: string
     quoteId: string
     orderHash: string
+    extension: string
 }
 
 export type PreparedOrder = {
diff --git a/src/ws-api/README.md b/src/ws-api/README.md
index b504979..bec5376 100644
--- a/src/ws-api/README.md
+++ b/src/ws-api/README.md
@@ -43,7 +43,7 @@ class MyFancyProvider implements WsProviderConnector {
     // ... user implementation
 }
 
-const url = 'wss://api.1inch.dev/fusion/ws/v1.0/1'
+const url = 'wss://api.1inch.dev/fusion/ws/v2.0/1'
 const provider = new MyFancyProvider({url})
 
 const wsSdk = new WebSocketApi(provider)
diff --git a/src/ws-api/ws-api.ts b/src/ws-api/ws-api.ts
index f2feceb..5ea3641 100644
--- a/src/ws-api/ws-api.ts
+++ b/src/ws-api/ws-api.ts
@@ -11,6 +11,8 @@ import {
 } from '../connector/ws'
 
 export class WebSocketApi {
+    private static Version = 'v2.0'
+
     public readonly rpc: RpcWebsocketApi
 
     public readonly order: ActiveOrdersWebSocketApi
@@ -22,7 +24,7 @@ export class WebSocketApi {
     ) {
         if (instanceOfWsApiConfigWithNetwork(configOrProvider)) {
             const url = castUrl(configOrProvider.url)
-            const urlWithNetwork = `${url}/v1.0/${configOrProvider.network}`
+            const urlWithNetwork = `${url}/${WebSocketApi.Version}/${configOrProvider.network}`
             const configWithUrl = {...configOrProvider, url: urlWithNetwork}
             const provider = new WebsocketClient(configWithUrl)
 
diff --git a/src/ws-api/ws.spec.ts b/src/ws-api/ws.spec.ts
index ed6126e..a2015f8 100644
--- a/src/ws-api/ws.spec.ts
+++ b/src/ws-api/ws.spec.ts
@@ -91,7 +91,7 @@ describe(__filename, () => {
             const port = 8080
 
             const url = `ws://localhost:${port}/ws`
-            const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+            const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
             wss.on('connection', (ws) => {
                 for (const m of [message]) {
@@ -136,7 +136,7 @@ describe(__filename, () => {
             const port = 8080
 
             const url = `ws://localhost:${port}/ws`
-            const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+            const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
             wss.on('connection', (ws) => {
                 for (const m of [message]) {
@@ -166,7 +166,7 @@ describe(__filename, () => {
             const port = 8080
 
             const url = `ws://localhost:${port}/ws`
-            const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+            const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
             wss.on('connection', (ws) => {
                 for (const m of [message]) {
@@ -175,7 +175,7 @@ describe(__filename, () => {
             })
 
             const castedUrl = castUrl(url)
-            const urlWithNetwork = `${castedUrl}/v1.0/1`
+            const urlWithNetwork = `${castedUrl}/v2.0/1`
             const provider = new WebsocketClient({url: urlWithNetwork})
 
             const wsSdk = new WebSocketApi(provider)
@@ -199,7 +199,7 @@ describe(__filename, () => {
             const port = 8080
 
             const url = `ws://localhost:${port}/ws`
-            const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+            const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
             wss.on('connection', (ws) => {
                 for (const m of [message]) {
@@ -208,7 +208,7 @@ describe(__filename, () => {
             })
 
             const castedUrl = castUrl(url)
-            const urlWithNetwork = `${castedUrl}/v1.0/1`
+            const urlWithNetwork = `${castedUrl}/v2.0/1`
             const provider = new WebsocketClient({
                 url: urlWithNetwork,
                 authKey: ''
@@ -828,7 +828,7 @@ function createWebsocketRpcServerMock(cb: (ws: WebSocket, data: any) => void): {
 } {
     const port = 8080
     const returnUrl = `ws://localhost:${port}/ws`
-    const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+    const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
     wss.on('connection', (ws) => {
         ws.on('message', (data) => cb(ws, data))
@@ -844,7 +844,7 @@ function createWebsocketServerMock(messages: any[]): {
     const port = 8080
 
     const returnUrl = `ws://localhost:${port}/ws`
-    const wss = new WebSocketServer({port, path: '/ws/v1.0/1'})
+    const wss = new WebSocketServer({port, path: '/ws/v2.0/1'})
 
     wss.on('connection', (ws) => {
         for (const message of messages) {