Add "library_path" metadata entry to OrtEpDevice instances for plugin and provider bridge EPs

onnxruntime/core/session/environment.cc

@@ -17,6 +17,7 @@
 #include "core/session/allocator_adapters.h"
 #include "core/session/inference_session.h"
 #include "core/session/onnxruntime_env_config_keys.h"
+#include "core/session/onnxruntime_ep_device_ep_metadata_keys.h"
 #include "core/session/plugin_ep/ep_factory_internal.h"
 #include "core/session/plugin_ep/ep_library_internal.h"
 #include "core/session/plugin_ep/ep_library_plugin.h"
@@ -896,8 +897,15 @@
         factory.GetSupportedDevices(&factory, sorted_devices.data(), sorted_devices.size(),
                                     ep_devices.data(), ep_devices.size(), &num_ep_devices)));
 
+    const auto* library_path = instance.library->LibraryPath();
     for (size_t i = 0; i < num_ep_devices; ++i) {
-      if (ep_devices[i] != nullptr) {                            // should never happen but just in case...
+      if (ep_devices[i] != nullptr) {  // should never happen but just in case...
+        if (library_path != nullptr) {
+          // Add library path to EP metadata if available.
+          // This is used by GenAI for custom library loading so we want to consistently set it.
+          ep_devices[i]->ep_metadata.Add(kOrtEpDevice_EpMetadataKey_LibraryPath, library_path->string());
+        }
+
         instance.execution_devices.emplace_back(ep_devices[i]);  // take ownership
       }
     }

onnxruntime/core/session/plugin_ep/ep_factory_provider_bridge.cc

@@ -22,11 +22,6 @@ OrtStatus* ProviderBridgeEpFactory::GetSupportedDevices(EpFactoryInternal& ep_fa
     auto* ep_device = ep_devices[i];
     if (ep_device) {
       ep_device->ep_factory = &ep_factory;
-
-      // Add library path to EP metadata if available
-      if (library_path_.has_value()) {
-        ep_device->ep_metadata.Add(kOrtEpDevice_EpMetadataKey_LibraryPath, library_path_->string());
-      }
     }
   }
 

onnxruntime/core/session/plugin_ep/ep_library.h

@@ -20,6 +20,7 @@ class EpLibrary {
   EpLibrary() = default;
 
   virtual const char* RegistrationName() const = 0;
+  virtual const std::filesystem::path* LibraryPath() const { return nullptr; }
   virtual Status Load() { return Status::OK(); }
   virtual const std::vector<OrtEpFactory*>& GetFactories() = 0;  // valid after Load()
   virtual Status Unload() { return Status::OK(); }

onnxruntime/core/session/plugin_ep/ep_library_plugin.h

@@ -25,6 +25,10 @@ class EpLibraryPlugin : public EpLibrary {
     return registration_name_.c_str();
   }
 
+  const std::filesystem::path* LibraryPath() const override {
+    return &library_path_;
+  }
+
   Status Load() override;
 
   const std::vector<OrtEpFactory*>& GetFactories() override {

onnxruntime/core/session/plugin_ep/ep_library_provider_bridge.h

@@ -22,7 +22,7 @@ class EpLibraryProviderBridge : public EpLibrary {
  public:
   EpLibraryProviderBridge(std::unique_ptr<ProviderLibrary> provider_library,
                           std::unique_ptr<EpLibrary> ep_library_plugin,
-                          std::optional<std::filesystem::path> library_path = std::nullopt)
+                          std::filesystem::path library_path)
       : provider_library_{std::move(provider_library)},
         ep_library_plugin_{std::move(ep_library_plugin)},
         library_path_{std::move(library_path)} {
@@ -32,6 +32,10 @@ class EpLibraryProviderBridge : public EpLibrary {
     return ep_library_plugin_->RegistrationName();
   }
 
+  const std::filesystem::path* LibraryPath() const override {
+    return &library_path_;
+  }
+
   const std::vector<OrtEpFactory*>& GetFactories() override {
     return factory_ptrs_;
   }
@@ -56,7 +60,7 @@ class EpLibraryProviderBridge : public EpLibrary {
   std::unique_ptr<EpLibrary> ep_library_plugin_;
 
   // Library path for EP metadata
-  std::optional<std::filesystem::path> library_path_;
+  std::filesystem::path library_path_;
 
   std::vector<std::unique_ptr<EpFactoryInternal>> factories_;
   std::vector<OrtEpFactory*> factory_ptrs_;                // for convenience

onnxruntime/test/autoep/test_registration.cc

@@ -74,6 +74,15 @@ TEST(OrtEpLibrary, LoadUnloadPluginLibraryCxxApi) {
   auto options = test_ep_device->EpOptions();
   ASSERT_STREQ(options.GetValue("run_really_fast"), "true");
 
+  // Verify the library path is present in the EP metadata
+  const char* metadata_library_path = metadata.GetValue(kOrtEpDevice_EpMetadataKey_LibraryPath);
+  ASSERT_NE(metadata_library_path, nullptr) << "Expected library_path to be present in EP metadata.";
+
+  // Verify the library path matches the registered path
+  std::filesystem::path metadata_path{metadata_library_path};
+  ASSERT_EQ(std::filesystem::canonical(metadata_path), std::filesystem::canonical(library_path))
+      << "Expected library_path in EP metadata to match the registered library path.";
+
   // the CPU device info will vary by machine so check for the lowest common denominator values
   Ort::ConstHardwareDevice device = test_ep_device->Device();
   ASSERT_EQ(device.Type(), OrtHardwareDeviceType_CPU);