docs: add vector search configuration for Azure AI Search

Author: benverhees

pages/docs/configuration/dotenv.mdx

@@ -435,6 +435,7 @@ This plugin supports searching Azure AI Search for answers to your questions. Se
     ['AZURE_AI_SEARCH_SEARCH_OPTION_QUERY_TYPE', 'string', 'The query type for Azure AI Search.','AZURE_AI_SEARCH_SEARCH_OPTION_QUERY_TYPE='],
     ['AZURE_AI_SEARCH_SEARCH_OPTION_TOP', 'number', 'The top count for Azure AI Search.','AZURE_AI_SEARCH_SEARCH_OPTION_TOP='],
     ['AZURE_AI_SEARCH_SEARCH_OPTION_SELECT', 'string', 'The select fields for Azure AI Search.','AZURE_AI_SEARCH_SEARCH_OPTION_SELECT='],
+    ['AZURE_AI_SEARCH_VECTOR_FIELDS', 'string', 'The names of the vector fields in your Azure AI Search index to use for vector search queries. Multiple fields can be specified as comma-separated values (e.g., \'field1,field2\'). Leave empty if you don\'t use vector search.','AZURE_AI_SEARCH_VECTOR_FIELDS='],
   ]}
 />
 

pages/docs/configuration/tools/azure_ai_search.mdx

@@ -103,7 +103,11 @@ Now select the free option or select your preferred option (may incur charges).
 ![image](/images/azure-ai-search/librechat_settings.png)
 
 
-**2.** Fill in the Endpoint, Index Name, and API Key, and click on `Save`.
+**2.** Fill in the Endpoint, Index Name, and API Key.
+
+**3.** (Optional) If you're using integrated vectorization, specify the Azure AI Search Vector Fields field with the comma-separated names of your vector fields (e.g., `vectorField1,vectorField2`). See [AZURE_AI_SEARCH_VECTOR_FIELDS](#azure_ai_search_vector_fields) for more details on vector search configuration.
+
+**4.** Click on `Save` to save your configuration.
 
 # Conclusion
 
@@ -121,15 +125,16 @@ For details on each parameter, please refer to the following document:
 **[https://learn.microsoft.com/en-us/rest/api/searchservice/search-documents](https://learn.microsoft.com/en-us/rest/api/searchservice/search-documents)**
 
 ```env
-AZURE_AI_SEARCH_API_VERSION=2023-10-01-Preview
+AZURE_AI_SEARCH_API_VERSION=2025-09-01
 AZURE_AI_SEARCH_SEARCH_OPTION_QUERY_TYPE=simple
 AZURE_AI_SEARCH_SEARCH_OPTION_TOP=3
 AZURE_AI_SEARCH_SEARCH_OPTION_SELECT=field1, field2, field3
+AZURE_AI_SEARCH_VECTOR_FIELDS=vectorField1,vectorField2
 ```
 
 #### AZURE_AI_SEARCH_API_VERSION
 
-Specify the version of the search API. When using new features such as semantic search or vector search, you may need to specify the preview version. The default value is `2023-11-1`.
+Specify the version of the search API. When using new features such as semantic search or vector search, you may need to specify the preview version. The default value is `2025-09-01`.
 
 #### AZURE_AI_SEARCH_SEARCH_OPTION_QUERY_TYPE
 
@@ -142,3 +147,15 @@ Specify the number of items to search for. The default value is 5.
 #### AZURE_AI_SEARCH_SEARCH_OPTION_SELECT
 
 Specify the fields of the index to be retrieved, separated by commas. Please note that these are not the fields to be searched.
+
+#### AZURE_AI_SEARCH_VECTOR_FIELDS
+
+Specify the names of the vector fields in your Azure AI Search index to use for vector search queries. Multiple fields can be specified as comma-separated values (e.g., `field1,field2`). Leave empty if you don't use vector search.
+
+When configured, this enables vector search capabilities in the Azure AI Search tool. The tool will accept a `vectorQueryText` parameter that will be vectorized and used to perform semantic similarity searches across the specified vector fields. You can use both keyword search (`query`) and vector search (`vectorQueryText`) together for hybrid search scenarios.
+
+**Prerequisite:** Your Azure AI Search index must have [integrated vectorization](https://learn.microsoft.com/en-us/azure/search/vector-search-integrated-vectorization#using-integrated-vectorization-in-queries) configured with vectorizers assigned to your vector fields. The field names specified in `AZURE_AI_SEARCH_VECTOR_FIELDS` must match the actual vector field names in your index that have vectorizers assigned.
+
+For more information on setting up vector search in Azure AI Search, see:
+- [Azure AI Search vector search overview](https://learn.microsoft.com/en-us/azure/search/vector-search-overview)
+- [Integrated vectorization in queries](https://learn.microsoft.com/en-us/azure/search/vector-search-integrated-vectorization#using-integrated-vectorization-in-queries)