diff --git a/elasticsearch-api/lib/elasticsearch/api/actions/simulate/ingest.rb b/elasticsearch-api/lib/elasticsearch/api/actions/simulate/ingest.rb
index 2b94c55862..6961cde2f9 100644
--- a/elasticsearch-api/lib/elasticsearch/api/actions/simulate/ingest.rb
+++ b/elasticsearch-api/lib/elasticsearch/api/actions/simulate/ingest.rb
@@ -45,9 +45,10 @@ module Actions
         #  If you specify this parameter in the request path, it is used for any documents that do not explicitly specify an index argument.
         # @option arguments [String] :pipeline The pipeline to use as the default pipeline.
         #  This value can be used to override the default pipeline of the index.
-        # @option arguments [String] :merge_type The method to be used when merging mapping_additions existing mappings. Mappings can be merged in the way mapping changes are merged into an existing index, or in
-        #  the way mapping changes are merged into existing templates. Some changes are allowed to templates that are not allowed to indices. For example,
-        #  a field cannot be changed to an incompatible type in an index, but can in a template. Server default: index.
+        # @option arguments [String] :merge_type The mapping merge type if mapping overrides are being provided in mapping_addition.
+        #  The allowed values are one of index or template.
+        #  The index option merges mappings the way they would be merged into an existing index.
+        #  The template option merges mappings the way they would be merged into a template. Server default: index.
         # @option arguments [Boolean] :error_trace When set to `true` Elasticsearch will include the full stack trace of errors
         #  when they occur.
         # @option arguments [String, Array<String>] :filter_path Comma-separated list of filters in dot notation which reduce the response
diff --git a/elasticsearch-api/lib/elasticsearch/api/actions/transform/set_upgrade_mode.rb b/elasticsearch-api/lib/elasticsearch/api/actions/transform/set_upgrade_mode.rb
new file mode 100644
index 0000000000..75c12bc322
--- /dev/null
+++ b/elasticsearch-api/lib/elasticsearch/api/actions/transform/set_upgrade_mode.rb
@@ -0,0 +1,50 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+# This code was automatically generated from the Elasticsearch Specification
+# See https://github.com/elastic/elasticsearch-specification
+# See Elasticsearch::ES_SPECIFICATION_COMMIT for commit hash.
+module Elasticsearch
+  module API
+    module Transform
+      module Actions
+        # Sets a cluster wide upgrade_mode setting that prepares transform indices for an upgrade.
+        #
+        # @option arguments [Hash] :headers Custom HTTP headers
+        #
+        # @see https://www.elastic.co/guide/en/elasticsearch/reference/current/transform-set-upgrade-mode.html
+        #
+        def set_upgrade_mode(arguments = {})
+          request_opts = { endpoint: arguments[:endpoint] || 'transform.set_upgrade_mode' }
+
+          arguments = arguments.clone
+          headers = arguments.delete(:headers) || {}
+
+          body = nil
+
+          method = Elasticsearch::API::HTTP_POST
+          path   = '_transform/set_upgrade_mode'
+          params = {}
+
+          Elasticsearch::API::Response.new(
+            perform_request(method, path, params, body, headers, request_opts)
+          )
+        end
+      end
+    end
+  end
+end
diff --git a/elasticsearch-api/lib/elasticsearch/api/version.rb b/elasticsearch-api/lib/elasticsearch/api/version.rb
index edb307eecc..dbcc7c2838 100644
--- a/elasticsearch-api/lib/elasticsearch/api/version.rb
+++ b/elasticsearch-api/lib/elasticsearch/api/version.rb
@@ -18,6 +18,6 @@
 module Elasticsearch
   module API
     VERSION = '9.2.0'.freeze
-    ES_SPECIFICATION_COMMIT = 'e64428b1c0ca92962cbbe474009513fc0e59d89f'.freeze
+    ES_SPECIFICATION_COMMIT = '65e7af798ccf8e50bffe7028e62a3f842c299dc8'.freeze
   end
 end
diff --git a/elasticsearch-api/spec/unit/actions/transform/set_upgrade_mode_spec.rb b/elasticsearch-api/spec/unit/actions/transform/set_upgrade_mode_spec.rb
new file mode 100644
index 0000000000..9dd1b158c1
--- /dev/null
+++ b/elasticsearch-api/spec/unit/actions/transform/set_upgrade_mode_spec.rb
@@ -0,0 +1,35 @@
+# Licensed to Elasticsearch B.V. under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch B.V. licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+require 'spec_helper'
+
+describe 'client.transform#set_upgrade_mode' do
+  let(:expected_args) do
+    [
+      'POST',
+      '_transform/set_upgrade_mode',
+      {},
+      nil,
+      {},
+      { endpoint: 'transform.set_upgrade_mode' }
+    ]
+  end
+
+  it 'performs the request' do
+    expect(client_double.transform.set_upgrade_mode).to be_a Elasticsearch::API::Response
+  end
+end