diff --git a/src/ros2_medkit_gateway/src/http/handlers/data_handlers.cpp b/src/ros2_medkit_gateway/src/http/handlers/data_handlers.cpp
index 78017c2..9f960f1 100644
--- a/src/ros2_medkit_gateway/src/http/handlers/data_handlers.cpp
+++ b/src/ros2_medkit_gateway/src/http/handlers/data_handlers.cpp
@@ -81,7 +81,10 @@ void DataHandlers::handle_list_data(const httplib::Request & req, httplib::Respo
         ext.ros2_type(topic_type);
         try {
           auto type_info = type_introspection->get_type_info(topic_type);
-          ext.type_info(type_info.schema);
+          json type_info_obj;
+          type_info_obj["schema"] = type_info.schema;
+          type_info_obj["default_value"] = type_info.default_value;
+          ext.type_info(type_info_obj);
         } catch (const std::exception & e) {
           RCLCPP_DEBUG(HandlerContext::logger(), "Could not get type info for topic '%s': %s", topic.name.c_str(),
                        e.what());
@@ -176,7 +179,10 @@ void DataHandlers::handle_get_data_item(const httplib::Request & req, httplib::R
       auto type_introspection = data_access_mgr->get_type_introspection();
       try {
         auto type_info = type_introspection->get_type_info(sample.message_type);
-        ext.type_info(type_info.schema);
+        json type_info_obj;
+        type_info_obj["schema"] = type_info.schema;
+        type_info_obj["default_value"] = type_info.default_value;
+        ext.type_info(type_info_obj);
       } catch (const std::exception & e) {
         RCLCPP_DEBUG(HandlerContext::logger(), "Could not get type info for topic '%s': %s", full_topic_path.c_str(),
                      e.what());
diff --git a/src/ros2_medkit_gateway/src/http/handlers/fault_handlers.cpp b/src/ros2_medkit_gateway/src/http/handlers/fault_handlers.cpp
index 14d6268..b1f92fd 100644
--- a/src/ros2_medkit_gateway/src/http/handlers/fault_handlers.cpp
+++ b/src/ros2_medkit_gateway/src/http/handlers/fault_handlers.cpp
@@ -21,6 +21,7 @@
 #include <filesystem>
 #include <fstream>
 #include <iomanip>
+#include <set>
 #include <sstream>
 #include <vector>
 
@@ -89,6 +90,35 @@ std::string validate_fault_code(const std::string & fault_code) {
   return "";
 }
 
+/// Helper to filter faults JSON array by a set of namespace prefixes
+/// Keeps faults where any reporting_source starts with any of the given prefixes
+json filter_faults_by_sources(const json & faults_array, const std::set<std::string> & source_prefixes) {
+  json filtered = json::array();
+  for (const auto & fault : faults_array) {
+    if (!fault.contains("reporting_sources")) {
+      continue;
+    }
+    const auto & sources = fault["reporting_sources"];
+    bool matches = false;
+    for (const auto & src : sources) {
+      const std::string src_str = src.get<std::string>();
+      for (const auto & prefix : source_prefixes) {
+        if (src_str.rfind(prefix, 0) == 0) {
+          matches = true;
+          break;
+        }
+      }
+      if (matches) {
+        break;
+      }
+    }
+    if (matches) {
+      filtered.push_back(fault);
+    }
+  }
+  return filtered;
+}
+
 }  // namespace
 
 void FaultHandlers::handle_list_all_faults(const httplib::Request & req, httplib::Response & res) {
@@ -170,7 +200,6 @@ void FaultHandlers::handle_list_faults(const httplib::Request & req, httplib::Re
                                  {{"entity_id", entity_id}});
       return;
     }
-    std::string namespace_path = entity_info.namespace_path;
 
     auto filter = parse_fault_status_param(req);
     if (!filter.is_valid) {
@@ -188,6 +217,92 @@ void FaultHandlers::handle_list_faults(const httplib::Request & req, httplib::Re
     bool include_clusters = req.get_param_value("include_clusters") == "true";
 
     auto fault_mgr = ctx_.node()->get_fault_manager();
+
+    // For Functions, aggregate faults from all host apps
+    // Functions don't have a single namespace_path - they host apps from potentially different namespaces
+    if (entity_info.type == EntityType::FUNCTION) {
+      // Get all faults (no namespace filter)
+      auto result = fault_mgr->get_faults("", filter.include_pending, filter.include_confirmed, filter.include_cleared,
+                                          include_muted, include_clusters);
+
+      if (!result.success) {
+        HandlerContext::send_error(res, StatusCode::ServiceUnavailable_503, ERR_SERVICE_UNAVAILABLE,
+                                   "Failed to get faults",
+                                   {{"details", result.error_message}, {entity_info.id_field, entity_id}});
+        return;
+      }
+
+      // Collect host app FQNs for filtering
+      const auto & cache = ctx_.node()->get_thread_safe_cache();
+      auto agg_configs = cache.get_entity_configurations(entity_id);
+      std::set<std::string> host_fqns;
+      for (const auto & node : agg_configs.nodes) {
+        if (!node.node_fqn.empty()) {
+          host_fqns.insert(node.node_fqn);
+        }
+      }
+
+      // Filter faults to only those from function's host apps
+      json filtered_faults = filter_faults_by_sources(result.data["faults"], host_fqns);
+
+      // Build response
+      json response = {{"items", filtered_faults}};
+
+      XMedkit ext;
+      ext.entity_id(entity_id);
+      ext.add("aggregation_level", "function");
+      ext.add("count", filtered_faults.size());
+      ext.add("host_count", host_fqns.size());
+
+      response["x-medkit"] = ext.build();
+      HandlerContext::send_json(res, response);
+      return;
+    }
+
+    // For Components, aggregate faults from all hosted apps
+    // Components group Apps, so we filter by the apps' FQNs rather than namespace (which is too broad)
+    if (entity_info.type == EntityType::COMPONENT) {
+      // Get all faults (no namespace filter)
+      auto result = fault_mgr->get_faults("", filter.include_pending, filter.include_confirmed, filter.include_cleared,
+                                          include_muted, include_clusters);
+
+      if (!result.success) {
+        HandlerContext::send_error(res, StatusCode::ServiceUnavailable_503, ERR_SERVICE_UNAVAILABLE,
+                                   "Failed to get faults",
+                                   {{"details", result.error_message}, {entity_info.id_field, entity_id}});
+        return;
+      }
+
+      // Collect hosted app FQNs for filtering
+      const auto & cache = ctx_.node()->get_thread_safe_cache();
+      auto app_ids = cache.get_apps_for_component(entity_id);
+      std::set<std::string> app_fqns;
+      for (const auto & app_id : app_ids) {
+        auto app = cache.get_app(app_id);
+        if (app && app->bound_fqn.has_value() && !app->bound_fqn->empty()) {
+          app_fqns.insert(app->bound_fqn.value());
+        }
+      }
+
+      // Filter faults to only those from component's hosted apps
+      json filtered_faults = filter_faults_by_sources(result.data["faults"], app_fqns);
+
+      // Build response
+      json response = {{"items", filtered_faults}};
+
+      XMedkit ext;
+      ext.entity_id(entity_id);
+      ext.add("aggregation_level", "component");
+      ext.add("count", filtered_faults.size());
+      ext.add("app_count", app_fqns.size());
+
+      response["x-medkit"] = ext.build();
+      HandlerContext::send_json(res, response);
+      return;
+    }
+
+    // For other entity types (App, Area), use namespace_path filtering
+    std::string namespace_path = entity_info.namespace_path;
     auto result = fault_mgr->get_faults(namespace_path, filter.include_pending, filter.include_confirmed,
                                         filter.include_cleared, include_muted, include_clusters);
 
diff --git a/src/ros2_medkit_gateway/src/http/handlers/handler_context.cpp b/src/ros2_medkit_gateway/src/http/handlers/handler_context.cpp
index 83ce391..afe882c 100644
--- a/src/ros2_medkit_gateway/src/http/handlers/handler_context.cpp
+++ b/src/ros2_medkit_gateway/src/http/handlers/handler_context.cpp
@@ -101,8 +101,8 @@ EntityInfo HandlerContext::get_entity_info(const std::string & entity_id) const
   // Search areas (O(1) lookup)
   if (auto area = cache.get_area(entity_id)) {
     info.type = EntityType::AREA;
-    info.namespace_path = "";  // Areas don't have namespace_path
-    info.fqn = "";
+    info.namespace_path = area->namespace_path;  // Use area's namespace for fault filtering
+    info.fqn = area->namespace_path;
     info.id_field = "area_id";
     info.error_name = "Area";
     return info;
diff --git a/src/ros2_medkit_gateway/src/native_topic_sampler.cpp b/src/ros2_medkit_gateway/src/native_topic_sampler.cpp
index 423d666..5034bb9 100644
--- a/src/ros2_medkit_gateway/src/native_topic_sampler.cpp
+++ b/src/ros2_medkit_gateway/src/native_topic_sampler.cpp
@@ -280,24 +280,17 @@ TopicSampleResult NativeTopicSampler::sample_topic(const std::string & topic_nam
 
     RCLCPP_DEBUG(node_->get_logger(), "sample_topic: Created GenericSubscription for '%s'", topic_name.c_str());
 
-    // Spin with timeout
+    // Wait for message using future with timeout
+    // The main executor will deliver callbacks - we just wait for the result
+    // Note: This works because HTTP requests are handled in a separate thread,
+    // while the main executor processes ROS callbacks
     const auto timeout = std::chrono::duration<double>(timeout_sec);
-    const auto start_time = std::chrono::steady_clock::now();
-
-    while (!received.load()) {
-      auto elapsed = std::chrono::steady_clock::now() - start_time;
-      if (elapsed >= timeout) {
-        RCLCPP_DEBUG(node_->get_logger(), "sample_topic: Timeout waiting for message on '%s'", topic_name.c_str());
-        result.has_data = false;
-        return result;
-      }
-
-      // Spin with small timeout to allow checking received flag
-      rclcpp::spin_some(node_->get_node_base_interface());
+    auto future_status = message_future.wait_for(timeout);
 
-      if (!received.load()) {
-        std::this_thread::sleep_for(std::chrono::milliseconds(10));
-      }
+    if (future_status == std::future_status::timeout) {
+      RCLCPP_DEBUG(node_->get_logger(), "sample_topic: Timeout waiting for message on '%s'", topic_name.c_str());
+      result.has_data = false;
+      return result;
     }
 
     // Deserialize message using JsonSerializer