Fix PDF upload on localhost by making LANGCHAIN_API_KEY optional

frontend/__tests__/lib/langgraph-server.test.ts

@@ -0,0 +1,99 @@
+
+import { Client } from '@langchain/langgraph-sdk';
+
+// Mock the dependencies
+jest.mock('@langchain/langgraph-sdk', () => {
+  return {
+    Client: jest.fn().mockImplementation(() => ({
+      threads: {
+        create: jest.fn(),
+      },
+    })),
+  };
+});
+
+jest.mock('../../lib/langgraph-base', () => {
+  return {
+    LangGraphBase: jest.fn(),
+  };
+});
+
+describe('langgraph-server', () => {
+  const originalEnv = process.env;
+
+  beforeEach(() => {
+    jest.resetModules();
+    process.env = { ...originalEnv };
+    process.env.NEXT_PUBLIC_LANGGRAPH_API_URL = 'http://localhost:2024';
+  });
+
+  afterAll(() => {
+    process.env = originalEnv;
+  });
+
+  it('should throw if NEXT_PUBLIC_LANGGRAPH_API_URL is missing', () => {
+    delete process.env.NEXT_PUBLIC_LANGGRAPH_API_URL;
+
+    expect(() => {
+      jest.isolateModules(() => {
+        require('../../lib/langgraph-server');
+      });
+    }).toThrow('NEXT_PUBLIC_LANGGRAPH_API_URL is not set');
+  });
+
+  it('should initialize without LANGCHAIN_API_KEY', () => {
+    delete process.env.LANGCHAIN_API_KEY;
+
+    expect(() => {
+      jest.isolateModules(() => {
+        require('../../lib/langgraph-server');
+      });
+    }).not.toThrow();
+  });
+
+  it('should initialize with LANGCHAIN_API_KEY if provided', () => {
+    process.env.LANGCHAIN_API_KEY = 'test-key';
+
+    expect(() => {
+      jest.isolateModules(() => {
+        require('../../lib/langgraph-server');
+      });
+    }).not.toThrow();
+  });
+
+  it('should pass API key to Client if provided', () => {
+    process.env.LANGCHAIN_API_KEY = 'test-key';
+
+    let ClientMock;
+    jest.isolateModules(() => {
+      require('../../lib/langgraph-server');
+      ClientMock = require('@langchain/langgraph-sdk').Client;
+    });
+
+    expect(ClientMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        defaultHeaders: expect.objectContaining({
+          'X-Api-Key': 'test-key',
+        }),
+      })
+    );
+  });
+
+  it('should not pass X-Api-Key header if LANGCHAIN_API_KEY is missing', () => {
+    delete process.env.LANGCHAIN_API_KEY;
+
+    let ClientMock;
+    jest.isolateModules(() => {
+      require('../../lib/langgraph-server');
+      ClientMock = require('@langchain/langgraph-sdk').Client;
+    });
+
+    expect(ClientMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        defaultHeaders: expect.not.objectContaining({
+          'X-Api-Key': expect.anything(),
+        }),
+      })
+    );
+  });
+});

frontend/lib/langgraph-server.ts

@@ -17,16 +17,17 @@ export const createServerClient = () => {
     throw new Error('NEXT_PUBLIC_LANGGRAPH_API_URL is not set');
   }
 
-  if (!process.env.LANGCHAIN_API_KEY) {
-    throw new Error('LANGCHAIN_API_KEY is not set');
+  const defaultHeaders: Record<string, string> = {
+    'Content-Type': 'application/json',
+  };
+
+  if (process.env.LANGCHAIN_API_KEY) {
+    defaultHeaders['X-Api-Key'] = process.env.LANGCHAIN_API_KEY;
   }
 
   const client = new Client({
     apiUrl: process.env.NEXT_PUBLIC_LANGGRAPH_API_URL,
-    defaultHeaders: {
-      'Content-Type': 'application/json',
-      'X-Api-Key': process.env.LANGCHAIN_API_KEY,
-    },
+    defaultHeaders,
   });
 
   clientInstance = new LangGraphBase(client);