diff --git a/x-pack/solutions/chat/plugins/wci-index-source/common/http_api/configuration.ts b/x-pack/solutions/chat/plugins/wci-index-source/common/http_api/configuration.ts
index 02e53ff34690b..d987fefcf407c 100644
--- a/x-pack/solutions/chat/plugins/wci-index-source/common/http_api/configuration.ts
+++ b/x-pack/solutions/chat/plugins/wci-index-source/common/http_api/configuration.ts
@@ -10,3 +10,7 @@ import type { IndexSourceDefinition } from '@kbn/wci-common';
 export interface GenerateConfigurationResponse {
   definition: IndexSourceDefinition;
 }
+
+export interface SearchIndicesResponse {
+  indexNames: string[];
+}
diff --git a/x-pack/solutions/chat/plugins/wci-index-source/public/hooks/use_index_name_autocomplete.ts b/x-pack/solutions/chat/plugins/wci-index-source/public/hooks/use_index_name_autocomplete.ts
new file mode 100644
index 0000000000000..5a979529f3677
--- /dev/null
+++ b/x-pack/solutions/chat/plugins/wci-index-source/public/hooks/use_index_name_autocomplete.ts
@@ -0,0 +1,56 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { useQuery } from '@tanstack/react-query';
+import { useState } from 'react';
+import useDebounce from 'react-use/lib/useDebounce';
+import type { CoreStart } from '@kbn/core/public';
+import { useKibana } from '@kbn/kibana-react-plugin/public';
+import type { SearchIndicesResponse } from '../../common/http_api/configuration';
+
+export const useIndexNameAutocomplete = ({ query }: { query: string }) => {
+  const {
+    services: { http, notifications },
+  } = useKibana<CoreStart>();
+
+  const [debouncedQuery, setDebounceQuery] = useState<string>(query);
+
+  useDebounce(
+    () => {
+      setDebounceQuery(query);
+    },
+    250,
+    [query]
+  );
+
+  const { isLoading, data } = useQuery({
+    queryKey: ['index-name-autocomplete', debouncedQuery],
+    queryFn: async () => {
+      if (query.length < 3) {
+        return [];
+      }
+      const response = await http.get<SearchIndicesResponse>(
+        `/internal/wci-index-source/indices-autocomplete`,
+        {
+          query: {
+            index: query,
+          },
+        }
+      );
+      return response.indexNames;
+    },
+    initialData: [],
+    onError: (err: any) => {
+      notifications.toasts.addError(err, { title: 'Error fetching indices' });
+    },
+  });
+
+  return {
+    isLoading,
+    data,
+  };
+};
diff --git a/x-pack/solutions/chat/plugins/wci-index-source/public/integration/configuration.tsx b/x-pack/solutions/chat/plugins/wci-index-source/public/integration/configuration.tsx
index b2af236828620..85b600df6268f 100644
--- a/x-pack/solutions/chat/plugins/wci-index-source/public/integration/configuration.tsx
+++ b/x-pack/solutions/chat/plugins/wci-index-source/public/integration/configuration.tsx
@@ -5,10 +5,11 @@
  * 2.0.
  */
 
-import React, { useCallback } from 'react';
+import React, { useCallback, useState } from 'react';
 import { useFieldArray, Controller } from 'react-hook-form';
 import {
   EuiTextArea,
+  EuiComboBox,
   EuiFormRow,
   EuiDescribedFormGroup,
   EuiFieldText,
@@ -21,11 +22,13 @@ import {
   EuiFlexItem,
   EuiCallOut,
   EuiButtonEmpty,
+  EuiComboBoxOptionOption,
 } from '@elastic/eui';
 import type { IndexSourceDefinition } from '@kbn/wci-common';
 import { IntegrationConfigurationFormProps } from '@kbn/wci-browser';
 import type { WCIIndexSourceFilterField, WCIIndexSourceContextField } from '../../common/types';
 import { useGenerateSchema } from '../hooks/use_generate_schema';
+import { useIndexNameAutocomplete } from '../hooks/use_index_name_autocomplete';
 
 export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationFormProps> = ({
   form,
@@ -35,6 +38,7 @@ export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationForm
     control,
     name: 'configuration.fields.filterFields',
   });
+  const [query, setQuery] = useState('');
 
   const contextFieldsArray = useFieldArray({
     control,
@@ -50,6 +54,16 @@ export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationForm
   ];
 
   const { generateSchema } = useGenerateSchema();
+  const { isLoading, data } = useIndexNameAutocomplete({ query });
+  const [selectedOptions, setSelected] = useState<EuiComboBoxOptionOption[]>([]);
+
+  const onIndexNameChange = (onChangeSelectedOptions: EuiComboBoxOptionOption[]) => {
+    setSelected(onChangeSelectedOptions);
+  };
+
+  const onSearchChange = (searchValue: string) => {
+    setQuery(searchValue);
+  };
 
   const onSchemaGenerated = useCallback(
     (definition: IndexSourceDefinition) => {
@@ -116,16 +130,28 @@ export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationForm
             name="configuration.index"
             control={control}
             render={({ field }) => (
-              <EuiFieldText
+              <EuiComboBox
                 data-test-subj="workchatAppIntegrationEditViewIndex"
-                placeholder="Enter index name"
-                {...field}
+                placeholder="Select an index"
+                isLoading={isLoading}
+                selectedOptions={selectedOptions}
+                singleSelection={{ asPlainText: true }}
+                options={data.map((option) => ({ label: option, key: option }))}
+                onChange={onIndexNameChange}
+                fullWidth={true}
+                onSearchChange={onSearchChange}
                 append={
                   <EuiButtonEmpty
                     size="xs"
                     iconType="gear"
                     onClick={() => {
-                      generateSchema({ indexName: field.value }, { onSuccess: onSchemaGenerated });
+                      if (selectedOptions.length === 0) return;
+                      if (!selectedOptions[0].key) return;
+
+                      generateSchema(
+                        { indexName: selectedOptions[0].key },
+                        { onSuccess: onSchemaGenerated }
+                      );
                     }}
                   >
                     Generate configuration
@@ -180,7 +206,7 @@ export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationForm
           </EuiFormRow>
         ) : (
           filterFieldsArray.fields.map((filterField, index) => (
-            <EuiPanel paddingSize="s" key={filterField.id} style={{ marginBottom: '8px' }}>
+            <EuiPanel paddingSize="s" key={filterField.id} css={{ marginBottom: '8px' }}>
               <EuiFlexGroup alignItems="center">
                 <EuiFlexItem>
                   <EuiFormRow label="Field name">
@@ -275,7 +301,7 @@ export const IndexSourceConfigurationForm: React.FC<IntegrationConfigurationForm
           </EuiFormRow>
         ) : (
           contextFieldsArray.fields.map((contextField, index) => (
-            <EuiPanel paddingSize="s" key={contextField.id} style={{ marginBottom: '8px' }}>
+            <EuiPanel paddingSize="s" key={contextField.id} css={{ marginBottom: '8px' }}>
               <EuiFlexGroup alignItems="center">
                 <EuiFlexItem>
                   <EuiFormRow label="Field name">
diff --git a/x-pack/solutions/chat/plugins/wci-index-source/server/routes/configuration.ts b/x-pack/solutions/chat/plugins/wci-index-source/server/routes/configuration.ts
index 442737b344ce7..ea8ca67b74fe1 100644
--- a/x-pack/solutions/chat/plugins/wci-index-source/server/routes/configuration.ts
+++ b/x-pack/solutions/chat/plugins/wci-index-source/server/routes/configuration.ts
@@ -9,7 +9,10 @@ import { schema } from '@kbn/config-schema';
 import { apiCapabilities } from '@kbn/workchat-app/common/features';
 import { buildSchema } from '@kbn/wc-index-schema-builder';
 import { getConnectorList, getDefaultConnector } from '@kbn/wc-genai-utils';
-import type { GenerateConfigurationResponse } from '../../common/http_api/configuration';
+import type {
+  GenerateConfigurationResponse,
+  SearchIndicesResponse,
+} from '../../common/http_api/configuration';
 import type { RouteDependencies } from './types';
 
 export const registerConfigurationRoutes = ({ router, core, logger }: RouteDependencies) => {
@@ -61,4 +64,57 @@ export const registerConfigurationRoutes = ({ router, core, logger }: RouteDepen
       }
     }
   );
+
+  router.get(
+    {
+      path: '/internal/wci-index-source/indices-autocomplete',
+      security: {
+        authz: {
+          requiredPrivileges: [apiCapabilities.manageWorkchat],
+        },
+      },
+      validate: {
+        query: schema.object({
+          index: schema.maybe(schema.string()),
+        }),
+      },
+    },
+    async (ctx, request, res) => {
+      const { elasticsearch } = await ctx.core;
+      let pattern = request.query.index || '';
+
+      if (pattern.length >= 3) {
+        pattern = `${pattern}*`;
+      }
+
+      const esClient = elasticsearch.client.asCurrentUser;
+
+      try {
+        const response = await esClient.cat.indices({
+          index: [pattern],
+          h: 'index',
+          expand_wildcards: 'open',
+          format: 'json',
+        });
+
+        return res.ok<SearchIndicesResponse>({
+          body: {
+            indexNames: response
+              .map((indexRecord) => indexRecord.index)
+              .filter((index) => !!index) as string[],
+          },
+        });
+      } catch (e) {
+        // TODO: sigh, is there a better way?
+        if (e?.meta?.body?.error?.type === 'index_not_found_exception') {
+          return res.ok<SearchIndicesResponse>({
+            body: {
+              indexNames: [],
+            },
+          });
+        }
+        throw e;
+      }
+    }
+  );
 };