🔐 feat: Implement Entra ID authentication for Azure OpenAI integration

- Added support for Entra ID authentication in OpenAIClient and related services.
- Updated header management to conditionally use Entra ID access tokens or API keys based on environment configuration.
- Introduced utility functions for Entra ID token retrieval and credential management.
- Enhanced tests to verify Entra ID authentication flow and its integration with Azure configurations.

api/server/services/Config/EndpointService.js

@@ -1,4 +1,4 @@
-const { isUserProvided } = require('@librechat/api');
+const { isUserProvided, shouldUseEntraId } = require('@librechat/api');
 const { EModelEndpoint } = require('librechat-data-provider');
 const { generateConfig } = require('~/server/utils/handleText');
 
@@ -17,23 +17,28 @@ const {
   AZURE_ASSISTANTS_BASE_URL,
 } = process.env ?? {};
 
+// Note: For Entra ID, we can't determine the actual token here since this is synchronous
+// The actual token will be obtained in the initialize functions.
+// Still we need to set a placeholder token to avoid errors.
+const finalAzureOpenAIApiKey = shouldUseEntraId() ? 'entra-id-placeholder' : azureOpenAIApiKey;
+
 const useAzurePlugins = !!PLUGINS_USE_AZURE;
 
 const userProvidedOpenAI = useAzurePlugins
-  ? isUserProvided(azureOpenAIApiKey)
+  ? isUserProvided(finalAzureOpenAIApiKey)
   : isUserProvided(openAIApiKey);
 
 module.exports = {
   config: {
     openAIApiKey,
-    azureOpenAIApiKey,
+    azureOpenAIApiKey: finalAzureOpenAIApiKey,
     useAzurePlugins,
     userProvidedOpenAI,
     googleKey,
     [EModelEndpoint.anthropic]: generateConfig(anthropicApiKey),
     [EModelEndpoint.chatGPTBrowser]: generateConfig(chatGPTToken),
     [EModelEndpoint.openAI]: generateConfig(openAIApiKey, OPENAI_REVERSE_PROXY),
-    [EModelEndpoint.azureOpenAI]: generateConfig(azureOpenAIApiKey, AZURE_OPENAI_BASEURL),
+    [EModelEndpoint.azureOpenAI]: generateConfig(finalAzureOpenAIApiKey, AZURE_OPENAI_BASEURL),
     [EModelEndpoint.assistants]: generateConfig(
       assistantsApiKey,
       ASSISTANTS_BASE_URL,

api/server/services/Endpoints/azureAssistants/initialize.js

@@ -1,6 +1,12 @@
 const OpenAI = require('openai');
 const { ProxyAgent } = require('undici');
-const { constructAzureURL, isUserProvided, resolveHeaders } = require('@librechat/api');
+const {
+  constructAzureURL,
+  isUserProvided,
+  resolveHeaders,
+  shouldUseEntraId,
+  getEntraIdAccessToken,
+} = require('@librechat/api');
 const { ErrorTypes, EModelEndpoint, mapModelToAzureConfig } = require('librechat-data-provider');
 const {
   checkUserKeyExpiry,
@@ -108,12 +114,19 @@ const initializeClient = async ({ req, res, version, endpointOption, initAppClie
       azureOptions,
     });
 
-    apiKey = azureOptions.azureOpenAIApiKey;
+    // For Entra ID, we need to get the actual access token
+    if (shouldUseEntraId()) {
+      apiKey = 'entra-id-placeholder';
+      headers['Authorization'] = `Bearer ${await getEntraIdAccessToken()}`;
+    } else {
+      apiKey = azureOptions.azureOpenAIApiKey;
+      headers['api-key'] = apiKey;
+    }
+
     opts.defaultQuery = { 'api-version': azureOptions.azureOpenAIApiVersion };
     opts.defaultHeaders = resolveHeaders({
       headers: {
         ...headers,
-        'api-key': apiKey,
         'OpenAI-Beta': `assistants=${version}`,
       },
       user: req.user,
@@ -137,7 +150,11 @@ const initializeClient = async ({ req, res, version, endpointOption, initAppClie
         clientOptions.defaultQuery = azureOptions.azureOpenAIApiVersion
           ? { 'api-version': azureOptions.azureOpenAIApiVersion }
           : undefined;
-        clientOptions.headers['api-key'] = apiKey;
+        if (shouldUseEntraId()) {
+          clientOptions.headers['Authorization'] = `Bearer ${await getEntraIdAccessToken()}`;
+        } else {
+          clientOptions.headers['api-key'] = apiKey;
+        }
       }
     }
   }

api/server/services/Endpoints/openAI/initialize.js

@@ -6,6 +6,8 @@ const {
   getOpenAIConfig,
   getAzureCredentials,
   createHandleLLMNewToken,
+  shouldUseEntraId,
+  getEntraIdAccessToken,
 } = require('@librechat/api');
 const { getUserKeyValues, checkUserKeyExpiry } = require('~/server/services/UserService');
 const OpenAIClient = require('~/app/clients/OpenAIClient');
@@ -106,11 +108,25 @@ const initializeClient = async ({
       clientOptions.defaultQuery = azureOptions.azureOpenAIApiVersion
         ? { 'api-version': azureOptions.azureOpenAIApiVersion }
         : undefined;
-      clientOptions.headers['api-key'] = apiKey;
+      if (shouldUseEntraId()) {
+        clientOptions.headers = {
+          ...clientOptions.headers,
+          Authorization: `Bearer ${await getEntraIdAccessToken()}`,
+        };
+      } else {
+        clientOptions.headers['api-key'] = apiKey;
+      }
     }
   } else if (isAzureOpenAI) {
     clientOptions.azure = userProvidesKey ? JSON.parse(userValues.apiKey) : getAzureCredentials();
     apiKey = clientOptions.azure.azureOpenAIApiKey;
+    if (shouldUseEntraId()) {
+      clientOptions.headers = {
+        ...clientOptions.headers,
+        Authorization: `Bearer ${await getEntraIdAccessToken()}`,
+      };
+      apiKey = 'entra-id-placeholder';
+    }
   }
 
   /** @type {undefined | TBaseEndpoint} */

api/server/services/Endpoints/openAI/initialize.spec.js

@@ -428,4 +428,29 @@ describe('initializeClient', () => {
     expect(result.openAIApiKey).toBe('test');
     expect(result.client.options.reverseProxyUrl).toBe('https://user-provided-url.com');
   });
+
+  test('should use Entra ID authentication when AZURE_OPENAI_USE_ENTRA_ID is enabled', async () => {
+    process.env.AZURE_OPENAI_USE_ENTRA_ID = 'true';
+    process.env.AZURE_API_KEY = 'test-azure-api-key';
+    process.env.AZURE_OPENAI_API_INSTANCE_NAME = 'test-instance';
+    process.env.AZURE_OPENAI_API_DEPLOYMENT_NAME = 'test-deployment';
+    process.env.AZURE_OPENAI_API_VERSION = '2024-12-01-preview';
+
+    const req = {
+      body: {
+        key: null,
+        endpoint: EModelEndpoint.azureOpenAI,
+        model: 'gpt-4-vision-preview',
+      },
+      user: { id: '123' },
+      app: { locals: {} },
+      config: mockAppConfig,
+    };
+    const res = {};
+    const endpointOption = {};
+
+    const result = await initializeClient({ req, res, endpointOption });
+
+    expect(result.openAIApiKey).toBeTruthy();
+  });
 });