diff --git a/simulation/halsim_gui/src/main/native/cpp/main.cpp b/simulation/halsim_gui/src/main/native/cpp/main.cpp
index 1f89929354..d0db8d4b16 100644
--- a/simulation/halsim_gui/src/main/native/cpp/main.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/main.cpp
@@ -23,6 +23,7 @@
 #include "DriverStationGui.h"
 #include "EncoderSimGui.h"
 #include "HALSimGui.h"
+#include "HALSimGuiExt.h"
 #include "NetworkTablesSimGui.h"
 #include "PCMSimGui.h"
 #include "PWMSimGui.h"
@@ -50,6 +51,17 @@ __declspec(dllexport)
 
   glass::SetStorageName("simgui");
 
+  HAL_RegisterExtension(HALSIMGUI_EXT_ADDGUIINIT,
+                        reinterpret_cast<void*>((AddGuiInitFn)&AddGuiInit));
+  HAL_RegisterExtension(
+      HALSIMGUI_EXT_ADDGUILATEEXECUTE,
+      reinterpret_cast<void*>((AddGuiLateExecuteFn)&AddGuiLateExecute));
+  HAL_RegisterExtension(
+      HALSIMGUI_EXT_ADDGUIEARLYEXECUTE,
+      reinterpret_cast<void*>((AddGuiEarlyExecuteFn)&AddGuiEarlyExecute));
+  HAL_RegisterExtension(HALSIMGUI_EXT_GUIEXIT,
+                        reinterpret_cast<void*>((GuiExitFn)&GuiExit));
+
   HALSimGui::GlobalInit();
   DriverStationGui::GlobalInit();
   gPlotProvider = std::make_unique<glass::PlotProvider>(
diff --git a/simulation/halsim_gui/src/main/native/include/HALSimGuiExt.h b/simulation/halsim_gui/src/main/native/include/HALSimGuiExt.h
new file mode 100644
index 0000000000..e60976e346
--- /dev/null
+++ b/simulation/halsim_gui/src/main/native/include/HALSimGuiExt.h
@@ -0,0 +1,26 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <functional>
+
+namespace halsimgui {
+
+// These functions can be used to hook into the GUI, and can be accessed
+// via HAL_RegisterExtensionListener
+
+#define HALSIMGUI_EXT_ADDGUIINIT "halsimgui::AddGuiInit"
+using AddGuiInitFn = void (*)(std::function<void()> initialize);
+
+#define HALSIMGUI_EXT_ADDGUILATEEXECUTE "halsimgui::AddGuiLateExecute"
+using AddGuiLateExecuteFn = void (*)(std::function<void()> execute);
+
+#define HALSIMGUI_EXT_ADDGUIEARLYEXECUTE "halsimgui::AddGuiEarlyExecute"
+using AddGuiEarlyExecuteFn = void (*)(std::function<void()> execute);
+
+#define HALSIMGUI_EXT_GUIEXIT "halsimgui::GuiExit"
+using GuiExitFn = void (*)();
+
+}  // namespace halsimgui