@@ -1,4 +1,4 @@
-// Copyright 2025 Google LLC
+// Copyright 2026 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -21,6 +21,8 @@ import "google/api/client.proto";
 import "google/api/field_behavior.proto";
 import "google/api/httpbody.proto";
 import "google/api/resource.proto";
+import "google/cloud/aiplatform/v1/operation.proto";
+import "google/longrunning/operations.proto";
 import "google/protobuf/struct.proto";
 
 option csharp_namespace = "Google.Cloud.AIPlatform.V1";
@@ -54,6 +56,23 @@ service ReasoningEngineExecutionService {
       body: "*"
     };
   }
+
+  // Async query using a reasoning engine.
+  rpc AsyncQueryReasoningEngine(AsyncQueryReasoningEngineRequest)
+      returns (google.longrunning.Operation) {
+    option (google.api.http) = {
+      post: "/v1/{name=projects/*/locations/*/reasoningEngines/*}:asyncQuery"
+      body: "*"
+      additional_bindings {
+        post: "/v1/{name=reasoningEngines/*}:asyncQuery"
+        body: "*"
+      }
+    };
+    option (google.longrunning.operation_info) = {
+      response_type: "AsyncQueryReasoningEngineResponse"
+      metadata_type: "AsyncQueryReasoningEngineOperationMetadata"
+    };
+  }
 }
 
 // Request message for [ReasoningEngineExecutionService.Query][].
@@ -103,3 +122,37 @@ message StreamQueryReasoningEngineRequest {
   // It is optional and defaults to "stream_query" if unspecified.
   string class_method = 3 [(google.api.field_behavior) = OPTIONAL];
 }
+
+// Request message for
+// [ReasoningEngineExecutionService.AsyncQueryReasoningEngine][google.cloud.aiplatform.v1.ReasoningEngineExecutionService.AsyncQueryReasoningEngine].
+message AsyncQueryReasoningEngineRequest {
+  // Required. The name of the ReasoningEngine resource to use.
+  // Format:
+  // `projects/{project}/locations/{location}/reasoningEngines/{reasoning_engine}`
+  string name = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "aiplatform.googleapis.com/ReasoningEngine"
+    }
+  ];
+
+  // Optional. Input Cloud Storage URI for the Async query.
+  string input_gcs_uri = 2 [(google.api.field_behavior) = OPTIONAL];
+
+  // Optional. Output Cloud Storage URI for the Async query.
+  string output_gcs_uri = 3 [(google.api.field_behavior) = OPTIONAL];
+}
+
+// Operation metadata message for
+// [ReasoningEngineExecutionService.AsyncQueryReasoningEngine][google.cloud.aiplatform.v1.ReasoningEngineExecutionService.AsyncQueryReasoningEngine].
+message AsyncQueryReasoningEngineOperationMetadata {
+  // The common part of the operation metadata.
+  GenericOperationMetadata generic_metadata = 1;
+}
+
+// Response message for
+// [ReasoningEngineExecutionService.AsyncQueryReasoningEngine][google.cloud.aiplatform.v1.ReasoningEngineExecutionService.AsyncQueryReasoningEngine].
+message AsyncQueryReasoningEngineResponse {
+  // Output Cloud Storage URI for the Async query.
+  string output_gcs_uri = 1;
+}