diff --git a/src/buy/components/Buy.tsx b/src/buy/components/Buy.tsx
index 949d7e9eba..28f800ee22 100644
--- a/src/buy/components/Buy.tsx
+++ b/src/buy/components/Buy.tsx
@@ -45,7 +45,6 @@ export function Buy({
   onSuccess,
   toToken,
   fromToken,
-  projectId,
 }: BuyReact) {
   return (
     <BuyProvider
@@ -57,7 +56,6 @@ export function Buy({
       onSuccess={onSuccess}
       toToken={toToken}
       fromToken={fromToken}
-      projectId={projectId}
     >
       <BuyContent className={className} />
     </BuyProvider>
diff --git a/src/buy/components/BuyDropdown.test.tsx b/src/buy/components/BuyDropdown.test.tsx
index d0e4b58e29..66c00eff80 100644
--- a/src/buy/components/BuyDropdown.test.tsx
+++ b/src/buy/components/BuyDropdown.test.tsx
@@ -1,6 +1,7 @@
 import { openPopup } from '@/ui-react/internal/utils/openPopup';
 import { act, fireEvent, render, screen } from '@testing-library/react';
 import { type Mock, beforeEach, describe, expect, it, vi } from 'vitest';
+import { useOnchainKit } from '../../core-react/useOnchainKit';
 import { BuyDropdown } from './BuyDropdown';
 import { useBuyContext } from './BuyProvider';
 import { degenToken, ethToken, usdcToken } from '../../token/constants';
@@ -29,6 +30,10 @@ vi.mock('wagmi', async () => {
   };
 });
 
+vi.mock('../../core-react/useOnchainKit', () => ({
+  useOnchainKit: vi.fn(),
+}));
+
 const mockStartPopupMonitor = vi.fn();
 
 const mockContextValue = {
@@ -40,7 +45,6 @@ const mockContextValue = {
   fromETH: { token: ethToken },
   fromUSDC: { token: usdcToken },
   from: { token: { symbol: 'DAI' } },
-  projectId: 'mock-project-id',
   startPopupMonitor: mockStartPopupMonitor,
   setIsDropdownOpen: vi.fn(),
 };
@@ -49,6 +53,9 @@ describe('BuyDropdown', () => {
   beforeEach(() => {
     vi.clearAllMocks();
     (useBuyContext as Mock).mockReturnValue(mockContextValue);
+    (useOnchainKit as Mock).mockReturnValue({
+      projectId: 'mock-project-id',
+    });
   });
 
   it('renders the dropdown with correct content', () => {
diff --git a/src/buy/components/BuyDropdown.tsx b/src/buy/components/BuyDropdown.tsx
index 7d4fd02288..b195148d74 100644
--- a/src/buy/components/BuyDropdown.tsx
+++ b/src/buy/components/BuyDropdown.tsx
@@ -1,3 +1,4 @@
+import { useOnchainKit } from '@/core-react/useOnchainKit';
 import { openPopup } from '@/ui-react/internal/utils/openPopup';
 import { useCallback, useMemo } from 'react';
 import { useAccount } from 'wagmi';
@@ -11,8 +12,8 @@ import { useBuyContext } from './BuyProvider';
 import { BuyTokenItem } from './BuyTokenItem';
 
 export function BuyDropdown() {
-  const { to, fromETH, fromUSDC, from, projectId, startPopupMonitor } =
-    useBuyContext();
+  const { projectId } = useOnchainKit();
+  const { to, fromETH, fromUSDC, from, startPopupMonitor } = useBuyContext();
   const { address } = useAccount();
 
   const handleOnrampClick = useCallback(
diff --git a/src/buy/components/BuyProvider.test.tsx b/src/buy/components/BuyProvider.test.tsx
index a618d3b562..3480e5b34f 100644
--- a/src/buy/components/BuyProvider.test.tsx
+++ b/src/buy/components/BuyProvider.test.tsx
@@ -145,7 +145,6 @@ const wrapper = ({ children }: { children: React.ReactNode }) => (
         config={{ maxSlippage: 5 }}
         experimental={{ useAggregator: true }}
         toToken={degenToken}
-        projectId="mock-project-id"
         fromToken={daiToken}
       >
         {children}
@@ -178,7 +177,6 @@ const renderWithProviders = ({
           onSuccess={onSuccess}
           toToken={degenToken}
           fromToken={daiToken}
-          projectId="mock-project-id"
         >
           <Component />
         </BuyProvider>
@@ -829,7 +827,6 @@ describe('BuyProvider', () => {
           <BuyProvider
             config={config}
             experimental={{ useAggregator: true }}
-            projectId="test"
             toToken={usdcToken}
           >
             {children}
diff --git a/src/buy/components/BuyProvider.tsx b/src/buy/components/BuyProvider.tsx
index f1104f3c46..24eb675d06 100644
--- a/src/buy/components/BuyProvider.tsx
+++ b/src/buy/components/BuyProvider.tsx
@@ -53,7 +53,6 @@ export function BuyProvider({
   onSuccess,
   toToken,
   fromToken,
-  projectId,
 }: BuyProviderReact) {
   const {
     config: { paymaster } = { paymaster: undefined },
@@ -89,6 +88,14 @@ export function BuyProvider({
 
   // Refreshes balances and inputs post-swap
   const resetInputs = useResetBuyInputs({ fromETH, fromUSDC, from, to });
+
+  const { projectId } = useOnchainKit();
+  if (!projectId) {
+    throw new Error(
+      'Buy: Project ID is required, please set the projectId in the OnchainKitProvider',
+    );
+  }
+
   // For batched transactions, listens to and awaits calls from the Wallet server
   const awaitCallsStatus = useAwaitCalls({
     accountConfig,
@@ -462,7 +469,6 @@ export function BuyProvider({
     setIsDropdownOpen,
     toToken,
     fromToken,
-    projectId,
     startPopupMonitor,
   });
 
diff --git a/src/buy/types.ts b/src/buy/types.ts
index 0177223f39..c74c4cd0bc 100644
--- a/src/buy/types.ts
+++ b/src/buy/types.ts
@@ -21,7 +21,6 @@ export type BuyReact = {
   onSuccess?: (transactionReceipt?: TransactionReceipt) => void; // An optional callback function that exposes the transaction receipt
   fromToken?: Token; // An optional token to swap from
   toToken: Token; // The token to swap to
-  projectId: string; // A CDP project ID (found at https://portal.cdp.coinbase.com/)
 };
 
 export type BuyContextType = {
@@ -41,7 +40,6 @@ export type BuyContextType = {
   transactionHash: string;
   isDropdownOpen: boolean;
   setIsDropdownOpen: (open: boolean) => void;
-  projectId: string;
   startPopupMonitor: (popupWindow: Window) => void;
 };
 
@@ -59,7 +57,6 @@ export type BuyProviderReact = {
   onSuccess?: (transactionReceipt?: TransactionReceipt) => void; // An optional callback function that exposes the transaction receipt
   fromToken?: Token;
   toToken: Token;
-  projectId: string;
 };
 
 export type BuyTokens = {