diff --git a/src/core/hle/service/sockets/nsd.cpp b/src/core/hle/service/sockets/nsd.cpp
index 491b76d48..dbe042ac1 100644
--- a/src/core/hle/service/sockets/nsd.cpp
+++ b/src/core/hle/service/sockets/nsd.cpp
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/hle/service/ipc_helpers.h"
@@ -8,6 +9,9 @@
 
 namespace Service::Sockets {
 
+constexpr Result ResultNotImplemented{ErrorModule::NSD, 1}; // Generic "not implemented"
+constexpr Result ResultNsdNotInitialized{ErrorModule::NSD, 2}; // Example, if needed
+constexpr Result ResultPermissionDenied{ErrorModule::NSD, 3}; // For nsd:a specific calls
 constexpr Result ResultOverflow{ErrorModule::NSD, 6};
 
 // This is nn::oe::ServerEnvironmentType
@@ -25,35 +29,96 @@ struct EnvironmentIdentifier {
 };
 static_assert(sizeof(EnvironmentIdentifier) == 0x8);
 
+// nn::nsd::Url (0x100-byte struct)
+struct Url {
+    std::array<u8, 0x100> value;
+};
+static_assert(sizeof(Url) == 0x100);
+
+// nn::nsd::SettingName (0x100-byte struct)
+struct SettingName {
+    std::array<u8, 0x100> value;
+};
+static_assert(sizeof(SettingName) == 0x100);
+
+// nn::nsd::DeviceId (0x10-byte struct)
+struct DeviceId {
+    std::array<u8, 0x10> value;
+};
+static_assert(sizeof(DeviceId) == 0x10);
+
+// nn::nsd::Fqdn (0x100-byte struct, containing a string)
+// Using FqdnStruct to avoid conflict with potential using alias for std::array<char, 0x100>
+struct FqdnStruct {
+    std::array<char, 0x100> value;
+};
+static_assert(sizeof(FqdnStruct) == 0x100);
+
+// nn::nsd::NasServiceSetting (0x108-byte struct)
+struct NasServiceSetting {
+    std::array<u8, 0x108> value;
+};
+static_assert(sizeof(NasServiceSetting) == 0x108);
+
+// nn::nsd::NasServiceName (0x10-byte struct)
+struct NasServiceName {
+    std::array<u8, 0x10> value;
+};
+static_assert(sizeof(NasServiceName) == 0x10);
+
+// nn::nsd::SaveData (0x12BF0-byte struct)
+struct SaveData {
+    std::array<u8, 0x12BF0> value;
+};
+static_assert(sizeof(SaveData) == 0x12BF0);
+
+// nn::nsd::detail::TestParameter (0x80-byte struct)
+struct TestParameter {
+    std::array<u8, 0x80> value;
+};
+static_assert(sizeof(TestParameter) == 0x80);
+
+// nn::nsd::DeleteMode (enum)
+enum class DeleteMode : u32 { // Assuming u32, adjust if different
+    Mode0 = 0,
+    Mode1 = 1,
+};
+
+// nn::nsd::ImportMode (enum)
+enum class ImportMode : u32 { // Assuming u32, adjust if different
+    Mode0 = 0,
+    Mode1 = 1,
+};
+
 NSD::NSD(Core::System& system_, const char* name) : ServiceFramework{system_, name} {
     // clang-format off
     static const FunctionInfo functions[] = {
-        {5, nullptr, "GetSettingUrl"},
-        {10, nullptr, "GetSettingName"},
+        {5, &NSD::GetSettingUrl, "GetSettingUrl"},
+        {10, &NSD::GetSettingName, "GetSettingName"},
         {11, &NSD::GetEnvironmentIdentifier, "GetEnvironmentIdentifier"},
-        {12, nullptr, "GetDeviceId"},
-        {13, nullptr, "DeleteSettings"},
-        {14, nullptr, "ImportSettings"},
-        {15, nullptr, "SetChangeEnvironmentIdentifierDisabled"},
+        {12, &NSD::GetDeviceId, "GetDeviceId"},
+        {13, &NSD::DeleteSettings, "DeleteSettings"},
+        {14, &NSD::ImportSettings, "ImportSettings"},
+        {15, &NSD::SetChangeEnvironmentIdentifierDisabled, "SetChangeEnvironmentIdentifierDisabled"},
         {20, &NSD::Resolve, "Resolve"},
         {21, &NSD::ResolveEx, "ResolveEx"},
-        {30, nullptr, "GetNasServiceSetting"},
-        {31, nullptr, "GetNasServiceSettingEx"},
-        {40, nullptr, "GetNasRequestFqdn"},
-        {41, nullptr, "GetNasRequestFqdnEx"},
-        {42, nullptr, "GetNasApiFqdn"},
-        {43, nullptr, "GetNasApiFqdnEx"},
-        {50, nullptr, "GetCurrentSetting"},
-        {51, nullptr, "WriteTestParameter"},
-        {52, nullptr, "ReadTestParameter"},
-        {60, nullptr, "ReadSaveDataFromFsForTest"},
-        {61, nullptr, "WriteSaveDataToFsForTest"},
-        {62, nullptr, "DeleteSaveDataOfFsForTest"},
-        {63, nullptr, "IsChangeEnvironmentIdentifierDisabled"},
-        {64, nullptr, "SetWithoutDomainExchangeFqdns"},
+        {30, &NSD::GetNasServiceSetting, "GetNasServiceSetting"},
+        {31, &NSD::GetNasServiceSettingEx, "GetNasServiceSettingEx"},
+        {40, &NSD::GetNasRequestFqdn, "GetNasRequestFqdn"},
+        {41, &NSD::GetNasRequestFqdnEx, "GetNasRequestFqdnEx"},
+        {42, &NSD::GetNasApiFqdn, "GetNasApiFqdn"},
+        {43, &NSD::GetNasApiFqdnEx, "GetNasApiFqdnEx"},
+        {50, &NSD::GetCurrentSetting, "GetCurrentSetting"},
+        {51, &NSD::WriteTestParameter, "WriteTestParameter"},
+        {52, &NSD::ReadTestParameter, "ReadTestParameter"},
+        {60, &NSD::ReadSaveDataFromFsForTest, "ReadSaveDataFromFsForTest"},
+        {61, &NSD::WriteSaveDataToFsForTest, "WriteSaveDataToFsForTest"},
+        {62, &NSD::DeleteSaveDataOfFsForTest, "DeleteSaveDataOfFsForTest"},
+        {63, &NSD::IsChangeEnvironmentIdentifierDisabled, "IsChangeEnvironmentIdentifierDisabled"},
+        {64, &NSD::SetWithoutDomainExchangeFqdns, "SetWithoutDomainExchangeFqdns"},
         {100, &NSD::GetApplicationServerEnvironmentType, "GetApplicationServerEnvironmentType"},
-        {101, nullptr, "SetApplicationServerEnvironmentType"},
-        {102, nullptr, "DeleteApplicationServerEnvironmentType"},
+        {101, &NSD::SetApplicationServerEnvironmentType, "SetApplicationServerEnvironmentType"},
+        {102, &NSD::DeleteApplicationServerEnvironmentType, "DeleteApplicationServerEnvironmentType"},
     };
     // clang-format on
 
@@ -121,6 +186,263 @@ void NSD::GetApplicationServerEnvironmentType(HLERequestContext& ctx) {
     rb.Push(static_cast<u32>(ServerEnvironmentType::Lp));
 }
 
+void NSD::GetSettingUrl(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetSettingUrl called");
+
+    Url url{}; // Zero-initialize
+    ctx.WriteBuffer(url); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetSettingName(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetSettingName called");
+
+    SettingName setting_name{}; // Zero-initialize
+    ctx.WriteBuffer(setting_name); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetDeviceId(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetDeviceId called");
+
+    DeviceId device_id{}; // Zero-initialize
+    // TODO: Fill with some dummy data if needed, e.g., from settings
+    // For now, just zeroed.
+    ctx.WriteBuffer(device_id); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::DeleteSettings(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    [[maybe_unused]] const auto delete_mode = rp.PopEnum<DeleteMode>();
+    [[maybe_unused]] const auto setting_name_buffer = ctx.ReadBuffer(0); // Type-0x5 input buffer for SettingName
+
+    LOG_WARNING(Service, "(STUBBED) DeleteSettings called, mode={}", static_cast<u32>(delete_mode));
+    // Real impl would use setting_name_buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess); // Or ResultNotImplemented
+}
+
+void NSD::ImportSettings(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    [[maybe_unused]] const auto import_mode = rp.PopEnum<ImportMode>();
+    [[maybe_unused]] const auto setting_name_buffer = ctx.ReadBuffer(0); // Type-0x5 input buffer for SettingName
+    [[maybe_unused]] const auto save_data_buffer = ctx.ReadBuffer(1);    // Type-0x5 input buffer for SaveData
+
+    LOG_WARNING(Service, "(STUBBED) ImportSettings called, mode={}", static_cast<u32>(import_mode));
+    // Real impl would use setting_name_buffer and save_data_buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess); // Or ResultNotImplemented
+}
+
+void NSD::SetChangeEnvironmentIdentifierDisabled(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    [[maybe_unused]] const bool disabled = rp.Pop<bool>();
+    LOG_WARNING(Service, "(STUBBED) SetChangeEnvironmentIdentifierDisabled called, disabled={}", disabled);
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetNasServiceSetting(HLERequestContext& ctx) {
+    [[maybe_unused]] const auto service_name_buffer = ctx.ReadBuffer(0); // Type-0x9 input buffer for NasServiceName
+
+    LOG_WARNING(Service, "(STUBBED) GetNasServiceSetting called");
+
+    NasServiceSetting service_setting{}; // Zero-initialize
+    ctx.WriteBuffer(service_setting);   // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetNasServiceSettingEx(HLERequestContext& ctx) {
+    [[maybe_unused]] const auto service_name_buffer = ctx.ReadBuffer(0); // Type-0x9 input buffer for NasServiceName
+
+    LOG_WARNING(Service, "(STUBBED) GetNasServiceSettingEx called");
+
+    NasServiceSetting service_setting{}; // Zero-initialize
+    ctx.WriteBuffer(service_setting);   // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 4};
+    rb.Push(ResultSuccess);         // Outer Result
+    rb.Push(ResultSuccess); // nn::nsd::InnerResult
+}
+
+void NSD::GetNasRequestFqdn(HLERequestContext& ctx) {
+    [[maybe_unused]] const auto service_name_buffer = ctx.ReadBuffer(0); // Type-0x9 input buffer for NasServiceName
+
+    LOG_WARNING(Service, "(STUBBED) GetNasRequestFqdn called");
+
+    FqdnStruct fqdn{};                       // Zero-initialize
+    ctx.WriteBuffer(fqdn); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetNasRequestFqdnEx(HLERequestContext& ctx) {
+    [[maybe_unused]] const auto service_name_buffer = ctx.ReadBuffer(0); // Type-0x9 input buffer for NasServiceName
+
+    LOG_WARNING(Service, "(STUBBED) GetNasRequestFqdnEx called");
+
+    FqdnStruct fqdn{};                       // Zero-initialize
+    ctx.WriteBuffer(fqdn); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 4};
+    rb.Push(ResultSuccess);         // Outer Result
+    rb.Push(ResultSuccess); // nn::nsd::InnerResult
+}
+
+void NSD::GetNasApiFqdn(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetNasApiFqdn called");
+
+    FqdnStruct fqdn{};                       // Zero-initialize
+    ctx.WriteBuffer(fqdn); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::GetNasApiFqdnEx(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetNasApiFqdnEx called");
+
+    FqdnStruct fqdn{};                       // Zero-initialize
+    ctx.WriteBuffer(fqdn); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 4};
+    rb.Push(ResultSuccess);         // Outer Result
+    rb.Push(ResultSuccess); // nn::nsd::InnerResult
+}
+
+bool NSD::IsNsdA() const {
+    // A simple way to check if this instance is nsd:a
+    // This relies on the name passed during construction.
+    return strncmp(service_name.c_str(), "nsd:a", 5) == 0;
+}
+
+void NSD::GetCurrentSetting(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) GetCurrentSetting called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+
+    SaveData save_data{};                 // Zero-initialize
+    ctx.WriteBuffer(save_data); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::WriteTestParameter(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) WriteTestParameter called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+    [[maybe_unused]] const auto test_param_buffer = ctx.ReadBuffer(0); // Type-0x5 input buffer for TestParameter
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::ReadTestParameter(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) ReadTestParameter called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+    TestParameter test_param{};           // Zero-initialize
+    ctx.WriteBuffer(test_param); // Type-0x6 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::ReadSaveDataFromFsForTest(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) ReadSaveDataFromFsForTest called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+    SaveData save_data{};                 // Zero-initialize
+    ctx.WriteBuffer(save_data); // Type-0x16 output buffer
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::WriteSaveDataToFsForTest(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) WriteSaveDataToFsForTest called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+    [[maybe_unused]] const auto save_data_buffer = ctx.ReadBuffer(0); // Type-0x15 input buffer for SaveData
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::DeleteSaveDataOfFsForTest(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) DeleteSaveDataOfFsForTest called");
+    if (!IsNsdA()) {
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultPermissionDenied);
+        return;
+    }
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::IsChangeEnvironmentIdentifierDisabled(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) IsChangeEnvironmentIdentifierDisabled called");
+    IPC::ResponseBuilder rb{ctx, 3}; // bool is 1 byte, Result is 2 bytes, total 3. Or is bool promoted? Assume u32 for IPC.
+    rb.Push(ResultSuccess);
+    rb.Push<u8>(false); // Return false (not disabled) by default
+}
+
+void NSD::SetWithoutDomainExchangeFqdns(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) SetWithoutDomainExchangeFqdns called");
+    // Takes type-0x5 input buffer containing an array of Fqdn. Max 2.
+    // Requires nsd!test_mode == 1
+    [[maybe_unused]] const auto fqdn_array_buffer = ctx.ReadBuffer(0);
+
+    // For now, assume it's not test mode or doesn't matter for stub
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::SetApplicationServerEnvironmentType(HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    [[maybe_unused]] const auto env_type = rp.PopEnum<ServerEnvironmentType>();
+    LOG_WARNING(Service, "(STUBBED) SetApplicationServerEnvironmentType called, type={}", static_cast<u8>(env_type));
+
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
+void NSD::DeleteApplicationServerEnvironmentType(HLERequestContext& ctx) {
+    LOG_WARNING(Service, "(STUBBED) DeleteApplicationServerEnvironmentType called");
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(ResultSuccess);
+}
+
 NSD::~NSD() = default;
 
 } // namespace Service::Sockets
diff --git a/src/core/hle/service/sockets/nsd.h b/src/core/hle/service/sockets/nsd.h
index b0cfec507..eaa3aefa1 100644
--- a/src/core/hle/service/sockets/nsd.h
+++ b/src/core/hle/service/sockets/nsd.h
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
@@ -21,6 +22,31 @@ private:
     void ResolveEx(HLERequestContext& ctx);
     void GetEnvironmentIdentifier(HLERequestContext& ctx);
     void GetApplicationServerEnvironmentType(HLERequestContext& ctx);
+
+    bool IsNsdA() const;
+
+    void GetSettingUrl(HLERequestContext& ctx);
+    void GetSettingName(HLERequestContext& ctx);
+    void GetDeviceId(HLERequestContext& ctx);
+    void DeleteSettings(HLERequestContext& ctx);
+    void ImportSettings(HLERequestContext& ctx);
+    void SetChangeEnvironmentIdentifierDisabled(HLERequestContext& ctx);
+    void GetNasServiceSetting(HLERequestContext& ctx);
+    void GetNasServiceSettingEx(HLERequestContext& ctx);
+    void GetNasRequestFqdn(HLERequestContext& ctx);
+    void GetNasRequestFqdnEx(HLERequestContext& ctx);
+    void GetNasApiFqdn(HLERequestContext& ctx);
+    void GetNasApiFqdnEx(HLERequestContext& ctx);
+    void GetCurrentSetting(HLERequestContext& ctx);
+    void WriteTestParameter(HLERequestContext& ctx);
+    void ReadTestParameter(HLERequestContext& ctx);
+    void ReadSaveDataFromFsForTest(HLERequestContext& ctx);
+    void WriteSaveDataToFsForTest(HLERequestContext& ctx);
+    void DeleteSaveDataOfFsForTest(HLERequestContext& ctx);
+    void IsChangeEnvironmentIdentifierDisabled(HLERequestContext& ctx);
+    void SetWithoutDomainExchangeFqdns(HLERequestContext& ctx);
+    void SetApplicationServerEnvironmentType(HLERequestContext& ctx);
+    void DeleteApplicationServerEnvironmentType(HLERequestContext& ctx);
 };
 
 } // namespace Service::Sockets
diff --git a/src/core/hle/service/sockets/sockets.cpp b/src/core/hle/service/sockets/sockets.cpp
index 676d24e03..1b2d58812 100644
--- a/src/core/hle/service/sockets/sockets.cpp
+++ b/src/core/hle/service/sockets/sockets.cpp
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
+// SPDX-FileCopyrightText: Copyright 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include "core/hle/service/server_manager.h"
@@ -12,6 +13,7 @@ namespace Service::Sockets {
 void LoopProcess(Core::System& system) {
     auto server_manager = std::make_unique<ServerManager>(system);
 
+    server_manager->RegisterNamedService("bsd:a", std::make_shared<BSD>(system, "bsd:a"));
     server_manager->RegisterNamedService("bsd:s", std::make_shared<BSD>(system, "bsd:s"));
     server_manager->RegisterNamedService("bsd:u", std::make_shared<BSD>(system, "bsd:u"));
     server_manager->RegisterNamedService("bsdcfg", std::make_shared<BSDCFG>(system));