From 678c58634b208b78e0be3bfa99142c650abb024e Mon Sep 17 00:00:00 2001
From: joshualitt <joshualitt@google.com>
Date: Thu, 22 Jan 2026 16:22:22 -0800
Subject: [PATCH] feat(core): Refresh agents after loading an extension.
 (#17355)

---
 packages/core/src/utils/extensionLoader.test.ts | 11 +++++++++++
 packages/core/src/utils/extensionLoader.ts      |  1 +
 2 files changed, 12 insertions(+)

diff --git a/packages/core/src/utils/extensionLoader.test.ts b/packages/core/src/utils/extensionLoader.test.ts
index 4ec6f3641b..351dc19067 100644
--- a/packages/core/src/utils/extensionLoader.test.ts
+++ b/packages/core/src/utils/extensionLoader.test.ts
@@ -36,6 +36,7 @@ describe('SimpleExtensionLoader', () => {
     typeof GeminiClient.prototype.setTools
   >;
   let mockHookSystemInit: MockInstance;
+  let mockAgentRegistryReload: MockInstance;
 
   const activeExtension: GeminiCLIExtension = {
     name: 'test-extension',
@@ -63,6 +64,7 @@ describe('SimpleExtensionLoader', () => {
     extensionReloadingEnabled = false;
     mockGeminiClientSetTools = vi.fn();
     mockHookSystemInit = vi.fn();
+    mockAgentRegistryReload = vi.fn();
     mockConfig = {
       getMcpClientManager: () => mockMcpClientManager,
       getEnableExtensionReloading: () => extensionReloadingEnabled,
@@ -73,6 +75,9 @@ describe('SimpleExtensionLoader', () => {
       getHookSystem: () => ({
         initialize: mockHookSystemInit,
       }),
+      getAgentRegistry: () => ({
+        reload: mockAgentRegistryReload,
+      }),
     } as unknown as Config;
   });
 
@@ -132,15 +137,18 @@ describe('SimpleExtensionLoader', () => {
             expect(mockRefreshServerHierarchicalMemory).toHaveBeenCalledOnce();
             expect(mockHookSystemInit).toHaveBeenCalledOnce();
             expect(mockGeminiClientSetTools).toHaveBeenCalledOnce();
+            expect(mockAgentRegistryReload).toHaveBeenCalledOnce();
           } else {
             expect(mockMcpClientManager.startExtension).not.toHaveBeenCalled();
             expect(mockRefreshServerHierarchicalMemory).not.toHaveBeenCalled();
             expect(mockHookSystemInit).not.toHaveBeenCalled();
             expect(mockGeminiClientSetTools).not.toHaveBeenCalledOnce();
+            expect(mockAgentRegistryReload).not.toHaveBeenCalled();
           }
           mockRefreshServerHierarchicalMemory.mockClear();
           mockHookSystemInit.mockClear();
           mockGeminiClientSetTools.mockClear();
+          mockAgentRegistryReload.mockClear();
 
           await loader.unloadExtension(activeExtension);
           if (reloadingEnabled) {
@@ -150,11 +158,13 @@ describe('SimpleExtensionLoader', () => {
             expect(mockRefreshServerHierarchicalMemory).toHaveBeenCalledOnce();
             expect(mockHookSystemInit).toHaveBeenCalledOnce();
             expect(mockGeminiClientSetTools).toHaveBeenCalledOnce();
+            expect(mockAgentRegistryReload).toHaveBeenCalledOnce();
           } else {
             expect(mockMcpClientManager.stopExtension).not.toHaveBeenCalled();
             expect(mockRefreshServerHierarchicalMemory).not.toHaveBeenCalled();
             expect(mockHookSystemInit).not.toHaveBeenCalled();
             expect(mockGeminiClientSetTools).not.toHaveBeenCalledOnce();
+            expect(mockAgentRegistryReload).not.toHaveBeenCalled();
           }
         });
 
@@ -175,6 +185,7 @@ describe('SimpleExtensionLoader', () => {
             ]);
             expect(mockRefreshServerHierarchicalMemory).toHaveBeenCalledOnce();
             expect(mockHookSystemInit).toHaveBeenCalledOnce();
+            expect(mockAgentRegistryReload).toHaveBeenCalledOnce();
           },
         );
       },
diff --git a/packages/core/src/utils/extensionLoader.ts b/packages/core/src/utils/extensionLoader.ts
index 45ad37bfcc..61091ed405 100644
--- a/packages/core/src/utils/extensionLoader.ts
+++ b/packages/core/src/utils/extensionLoader.ts
@@ -112,6 +112,7 @@ export abstract class ExtensionLoader {
       // cache, we want to only do it once.
       await refreshServerHierarchicalMemory(this.config);
       await this.config.getHookSystem()?.initialize();
+      await this.config.getAgentRegistry().reload();
     }
   }