diff --git a/archon-ui-main/src/config/api.ts b/archon-ui-main/src/config/api.ts
index b77bf3904c..5f2fa58ee0 100644
--- a/archon-ui-main/src/config/api.ts
+++ b/archon-ui-main/src/config/api.ts
@@ -7,15 +7,29 @@
 
 // Get the API URL from environment or construct it
 export function getApiUrl(): string {
-  // Check if VITE_API_URL is provided (set by docker-compose)
+  // 1. Priority: VITE_API_URL from environment (e.g., Docker)
   if (import.meta.env.VITE_API_URL) {
-    return import.meta.env.VITE_API_URL;
+    return import.meta.env.VITE_API_URL
   }
 
-  // In both development (via Vite proxy) and production, we use a relative path.
-  // This ensures that requests are proxied correctly by the dev server or
-  // sent to the same origin in production.
-  return '';
+  // 2. Production mode: Use relative path
+  if (import.meta.env.PROD) {
+    return ''
+  }
+
+  // 3. Development mode: Construct URL from port
+  const port = import.meta.env.ARCHON_SERVER_PORT
+  if (!port) {
+    throw new Error(
+      'ARCHON_SERVER_PORT environment variable is required. ' +
+        'Please set it in your .env file. ' +
+        'Default value: 8181',
+    )
+  }
+
+  const protocol = window.location.protocol
+  const hostname = window.location.hostname
+  return `${protocol}//${hostname}:${port}`
 }
 
 // Get the base path for API endpoints
diff --git a/archon-ui-main/src/services/mcpClientService.ts b/archon-ui-main/src/services/mcpClientService.ts
index 2010c9bfec..1c73d6683a 100644
--- a/archon-ui-main/src/services/mcpClientService.ts
+++ b/archon-ui-main/src/services/mcpClientService.ts
@@ -89,13 +89,11 @@ const MCPToolSchema = z.object({
 export type MCPTool = z.infer<typeof MCPToolSchema>;
 export type MCPParameter = z.infer<typeof MCPParameterSchema>;
 
-import { getApiUrl } from '../config/api';
-
 /**
  * MCP Client Service - Universal MCP client that connects to any MCP servers
  * This service communicates with the standalone Python MCP client service
  */
-class MCPClientService {
+export class MCPClientService {
   private baseUrl = getApiUrl();
 
   // ========================================
diff --git a/archon-ui-main/test/config/api.test.ts b/archon-ui-main/test/config/api.test.ts
index ac06c78ef3..db4ea470f2 100644
--- a/archon-ui-main/test/config/api.test.ts
+++ b/archon-ui-main/test/config/api.test.ts
@@ -47,10 +47,11 @@ describe('API Configuration', () => {
       delete (import.meta.env as any).VITE_API_URL;
       delete (import.meta.env as any).ARCHON_SERVER_PORT;
       
-      const { getApiUrl } = await import('../../src/config/api');
-      
-      expect(() => getApiUrl()).toThrow('ARCHON_SERVER_PORT environment variable is required');
-      expect(() => getApiUrl()).toThrow('Default value: 8181');
+      // The import() promise should reject because a top-level statement calls getApiUrl()
+      // which will throw an error when ARCHON_SERVER_PORT is not set.
+      await expect(import('../../src/config/api')).rejects.toThrow(
+        /ARCHON_SERVER_PORT environment variable is required.*Default value: 8181/
+      );
     });
 
     it('should use ARCHON_SERVER_PORT when set in development', async () => {
diff --git a/archon-ui-main/test/errors.test.tsx b/archon-ui-main/test/errors.test.tsx
index 092a099415..3d955331a7 100644
--- a/archon-ui-main/test/errors.test.tsx
+++ b/archon-ui-main/test/errors.test.tsx
@@ -37,7 +37,6 @@ describe('Error Handling Tests', () => {
   })
 
   test('timeout error simulation', async () => {
-    vi.useFakeTimers()
     const MockTimeoutComponent = () => {
       const [status, setStatus] = React.useState('idle')
       
@@ -62,14 +61,8 @@ describe('Error Handling Tests', () => {
     fireEvent.click(screen.getByText('Start Request'))
     expect(screen.getByText('Loading...')).toBeInTheDocument()
     
-    // Fast-forward time
-    await act(async () => {
-      await vi.advanceTimersByTimeAsync(150)
-    })
-
-    const alert = await screen.findByRole('alert')
+    const alert = await screen.findByRole('alert', {}, { timeout: 500 })
     expect(alert).toHaveTextContent('Request timed out')
-    vi.useRealTimers()
   })
 
   test('form validation errors', () => {