feat: Add /config refresh command (#4993)

Co-authored-by: Bryan Morgan <bryanmorgan@google.com>

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -29,6 +29,7 @@ import { statsCommand } from '../ui/commands/statsCommand.js';
 import { themeCommand } from '../ui/commands/themeCommand.js';
 import { toolsCommand } from '../ui/commands/toolsCommand.js';
 import { vimCommand } from '../ui/commands/vimCommand.js';
+import { configCommand } from '../ui/commands/configCommand.js';
 
 /**
  * Loads the core, hard-coded slash commands that are an integral part
@@ -54,6 +55,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
       compressCommand,
       copyCommand,
       corgiCommand,
+      configCommand,
       docsCommand,
       editorCommand,
       extensionsCommand,

packages/cli/src/ui/App.tsx

@@ -39,8 +39,12 @@ import { EditorSettingsDialog } from './components/EditorSettingsDialog.js';
 import { ShellConfirmationDialog } from './components/ShellConfirmationDialog.js';
 import { Colors } from './colors.js';
 import { Help } from './components/Help.js';
-import { loadHierarchicalGeminiMemory } from '../config/config.js';
-import { LoadedSettings } from '../config/settings.js';
+import {
+  loadHierarchicalGeminiMemory,
+  loadCliConfig,
+  parseArguments,
+} from '../config/config.js';
+import { LoadedSettings, loadSettings } from '../config/settings.js';
 import { Tips } from './components/Tips.js';
 import { ConsolePatcher } from './utils/ConsolePatcher.js';
 import { registerCleanup } from '../utils/cleanup.js';
@@ -62,6 +66,7 @@ import {
   AuthType,
   type IdeContext,
   ideContext,
+  sessionId,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from '../config/auth.js';
 import { useLogger } from './hooks/useLogger.js';
@@ -89,6 +94,7 @@ import { OverflowProvider } from './contexts/OverflowContext.js';
 import { ShowMoreLines } from './components/ShowMoreLines.js';
 import { PrivacyNotice } from './privacy/PrivacyNotice.js';
 import { appEvents, AppEvent } from '../utils/events.js';
+import { loadExtensions } from '../config/extension.js';
 
 const CTRL_EXIT_PROMPT_DURATION_MS = 1000;
 
@@ -107,12 +113,14 @@ export const AppWrapper = (props: AppProps) => (
   </SessionStatsProvider>
 );
 
-const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
+const App = (props: AppProps) => {
+  const [config, setConfig] = useState<Config>(props.config);
+  const [settings, setSettings] = useState<LoadedSettings>(props.settings);
   const isFocused = useFocus();
   useBracketedPaste();
   const [updateMessage, setUpdateMessage] = useState<string | null>(null);
   const { stdout } = useStdout();
-  const nightly = version.includes('nightly');
+  const nightly = props.version.includes('nightly');
 
   useEffect(() => {
     checkForUpdates().then(setUpdateMessage);
@@ -307,6 +315,22 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
     }
   }, [config, addItem, settings.merged]);
 
+  const refreshConfig = useCallback(async () => {
+    const newSettings = loadSettings(process.cwd());
+    const newExtensions = loadExtensions(process.cwd());
+    const argv = await parseArguments();
+    const newConfig = await loadCliConfig(
+      newSettings.merged,
+      newExtensions,
+      sessionId,
+      argv,
+    );
+    await newConfig.initialize();
+    setConfig(newConfig);
+    setSettings(newSettings);
+    setGeminiMdFileCount(newConfig.getGeminiMdFileCount());
+  }, []);
+
   // Watch for model changes (e.g., from Flash fallback)
   useEffect(() => {
     const checkModelChange = () => {
@@ -474,6 +498,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
     openPrivacyNotice,
     toggleVimEnabled,
     setIsProcessing,
+    refreshConfig,
   );
 
   const {
@@ -777,7 +802,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
               {!settings.merged.hideBanner && (
                 <Header
                   terminalWidth={terminalWidth}
-                  version={version}
+                  version={props.version}
                   nightly={nightly}
                 />
               )}
@@ -821,7 +846,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
         {showHelp && <Help commands={slashCommands} />}
 
         <Box flexDirection="column" ref={mainControlsRef}>
-          {startupWarnings.length > 0 && (
+          {props.startupWarnings && props.startupWarnings.length > 0 && (
             <Box
               borderStyle="round"
               borderColor={Colors.AccentYellow}
@@ -829,7 +854,7 @@ const App = ({ config, settings, startupWarnings = [], version }: AppProps) => {
               marginY={1}
               flexDirection="column"
             >
-              {startupWarnings.map((warning, index) => (
+              {props.startupWarnings.map((warning, index) => (
                 <Text key={index} color={Colors.AccentYellow}>
                   {warning}
                 </Text>

packages/cli/src/ui/commands/configCommand.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  CommandKind,
+  SlashCommand,
+  SlashCommandActionReturn,
+} from './types.js';
+
+export const configCommand: SlashCommand = {
+  name: 'config',
+  description: 'Commands for interacting with the CLI configuration.',
+  kind: CommandKind.BUILT_IN,
+  subCommands: [
+    {
+      name: 'refresh',
+      description: 'Reload settings and extensions from the filesystem.',
+      kind: CommandKind.BUILT_IN,
+      action: async (context): Promise<SlashCommandActionReturn> => {
+        await context.ui.refreshConfig();
+        return {
+          type: 'message',
+          messageType: 'info',
+          content:
+            'Configuration, extensions, memory, and tools have been refreshed.',
+        };
+      },
+    },
+  ],
+};

packages/cli/src/ui/commands/types.ts

@@ -59,6 +59,7 @@ export interface CommandContext {
     /** Toggles a special display mode. */
     toggleCorgiMode: () => void;
     toggleVimEnabled: () => Promise<boolean>;
+    refreshConfig: () => Promise<void>;
   };
   // Session-specific data
   session: {

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -50,6 +50,7 @@ export const useSlashCommandProcessor = (
   openPrivacyNotice: () => void,
   toggleVimEnabled: () => Promise<boolean>,
   setIsProcessing: (isProcessing: boolean) => void,
+  refreshConfig: () => Promise<void>,
 ) => {
   const session = useSessionStats();
   const [commands, setCommands] = useState<readonly SlashCommand[]>([]);
@@ -158,6 +159,7 @@ export const useSlashCommandProcessor = (
         setPendingItem: setPendingCompressionItem,
         toggleCorgiMode,
         toggleVimEnabled,
+        refreshConfig,
       },
       session: {
         stats: session.stats,
@@ -180,6 +182,7 @@ export const useSlashCommandProcessor = (
       toggleCorgiMode,
       toggleVimEnabled,
       sessionShellAllowlist,
+      refreshConfig,
     ],
   );
 

packages/core/src/config/config.ts

@@ -188,60 +188,62 @@ export interface ConfigParameters {
 export class Config {
   private toolRegistry!: ToolRegistry;
   private promptRegistry!: PromptRegistry;
-  private readonly sessionId: string;
+  private sessionId: string;
   private contentGeneratorConfig!: ContentGeneratorConfig;
-  private readonly embeddingModel: string;
-  private readonly sandbox: SandboxConfig | undefined;
-  private readonly targetDir: string;
-  private readonly debugMode: boolean;
-  private readonly question: string | undefined;
-  private readonly fullContext: boolean;
-  private readonly coreTools: string[] | undefined;
-  private readonly excludeTools: string[] | undefined;
-  private readonly toolDiscoveryCommand: string | undefined;
-  private readonly toolCallCommand: string | undefined;
-  private readonly mcpServerCommand: string | undefined;
-  private readonly mcpServers: Record<string, MCPServerConfig> | undefined;
+  private embeddingModel: string;
+  private sandbox: SandboxConfig | undefined;
+  private targetDir: string;
+  private debugMode: boolean;
+  private question: string | undefined;
+  private fullContext: boolean;
+  private coreTools: string[] | undefined;
+  private excludeTools: string[] | undefined;
+  private toolDiscoveryCommand: string | undefined;
+  private toolCallCommand: string | undefined;
+  private mcpServerCommand: string | undefined;
+  private mcpServers: Record<string, MCPServerConfig> | undefined;
   private userMemory: string;
   private geminiMdFileCount: number;
   private approvalMode: ApprovalMode;
-  private readonly showMemoryUsage: boolean;
-  private readonly accessibility: AccessibilitySettings;
-  private readonly telemetrySettings: TelemetrySettings;
-  private readonly usageStatisticsEnabled: boolean;
+  private showMemoryUsage: boolean;
+  private accessibility: AccessibilitySettings;
+  private telemetrySettings: TelemetrySettings;
+  private usageStatisticsEnabled: boolean;
   private geminiClient!: GeminiClient;
-  private readonly fileFiltering: {
+  private fileFiltering: {
     respectGitIgnore: boolean;
     respectGeminiIgnore: boolean;
     enableRecursiveFileSearch: boolean;
   };
   private fileDiscoveryService: FileDiscoveryService | null = null;
   private gitService: GitService | undefined = undefined;
-  private readonly checkpointing: boolean;
-  private readonly proxy: string | undefined;
-  private readonly cwd: string;
-  private readonly bugCommand: BugCommandSettings | undefined;
-  private readonly model: string;
-  private readonly extensionContextFilePaths: string[];
-  private readonly noBrowser: boolean;
-  private readonly ideMode: boolean;
-  private readonly ideClient: IdeClient | undefined;
+  private checkpointing: boolean;
+  private proxy: string | undefined;
+  private cwd: string;
+  private bugCommand: BugCommandSettings | undefined;
+  private model: string;
+  private extensionContextFilePaths: string[];
+  private noBrowser: boolean;
+  private ideMode: boolean;
+  private ideClient: IdeClient | undefined;
   private modelSwitchedDuringSession: boolean = false;
-  private readonly maxSessionTurns: number;
-  private readonly listExtensions: boolean;
-  private readonly _extensions: GeminiCLIExtension[];
-  private readonly _blockedMcpServers: Array<{
+  private maxSessionTurns: number;
+  private listExtensions: boolean;
+  private _extensions: GeminiCLIExtension[];
+  private _blockedMcpServers: Array<{
     name: string;
     extensionName: string;
   }>;
   flashFallbackHandler?: FlashFallbackHandler;
   private quotaErrorOccurred: boolean = false;
-  private readonly summarizeToolOutput:
+  private summarizeToolOutput:
     | Record<string, SummarizeToolOutputSettings>
     | undefined;
-  private readonly experimentalAcp: boolean = false;
+  private experimentalAcp: boolean = false;
+  private _params: ConfigParameters;
 
   constructor(params: ConfigParameters) {
+    this._params = params;
     this.sessionId = params.sessionId;
     this.embeddingModel =
       params.embeddingModel ?? DEFAULT_GEMINI_EMBEDDING_MODEL;
@@ -310,6 +312,68 @@ export class Config {
     }
   }
 
+  async refresh() {
+    // Re-run initialization logic.
+    await this.initialize();
+    // After re-initializing, the tool registry will be updated.
+    // We need to update the gemini client with the new tools.
+    await this.geminiClient.setTools();
+  }
+
+  update(params: ConfigParameters) {
+    this._params = params;
+    // Re-assign all properties from the new params.
+    this.sessionId = params.sessionId;
+    this.embeddingModel =
+      params.embeddingModel ?? DEFAULT_GEMINI_EMBEDDING_MODEL;
+    this.sandbox = params.sandbox;
+    this.targetDir = path.resolve(params.targetDir);
+    this.debugMode = params.debugMode;
+    this.question = params.question;
+    this.fullContext = params.fullContext ?? false;
+    this.coreTools = params.coreTools;
+    this.excludeTools = params.excludeTools;
+    this.toolDiscoveryCommand = params.toolDiscoveryCommand;
+    this.toolCallCommand = params.toolCallCommand;
+    this.mcpServerCommand = params.mcpServerCommand;
+    this.mcpServers = params.mcpServers;
+    this.userMemory = params.userMemory ?? '';
+    this.geminiMdFileCount = params.geminiMdFileCount ?? 0;
+    this.approvalMode = params.approvalMode ?? ApprovalMode.DEFAULT;
+    this.showMemoryUsage = params.showMemoryUsage ?? false;
+    this.accessibility = params.accessibility ?? {};
+    this.telemetrySettings = {
+      enabled: params.telemetry?.enabled ?? false,
+      target: params.telemetry?.target ?? DEFAULT_TELEMETRY_TARGET,
+      otlpEndpoint: params.telemetry?.otlpEndpoint ?? DEFAULT_OTLP_ENDPOINT,
+      logPrompts: params.telemetry?.logPrompts ?? true,
+      outfile: params.telemetry?.outfile,
+    };
+    this.usageStatisticsEnabled = params.usageStatisticsEnabled ?? true;
+    this.fileFiltering = {
+      respectGitIgnore: params.fileFiltering?.respectGitIgnore ?? true,
+      respectGeminiIgnore: params.fileFiltering?.respectGeminiIgnore ?? true,
+      enableRecursiveFileSearch:
+        params.fileFiltering?.enableRecursiveFileSearch ?? true,
+    };
+    this.checkpointing = params.checkpointing ?? false;
+    this.proxy = params.proxy;
+    this.cwd = params.cwd ?? process.cwd();
+    this.fileDiscoveryService = params.fileDiscoveryService ?? null;
+    this.bugCommand = params.bugCommand;
+    this.model = params.model;
+    this.extensionContextFilePaths = params.extensionContextFilePaths ?? [];
+    this.maxSessionTurns = params.maxSessionTurns ?? -1;
+    this.experimentalAcp = params.experimentalAcp ?? false;
+    this.listExtensions = params.listExtensions ?? false;
+    this._extensions = params.extensions ?? [];
+    this._blockedMcpServers = params.blockedMcpServers ?? [];
+    this.noBrowser = params.noBrowser ?? false;
+    this.summarizeToolOutput = params.summarizeToolOutput;
+    this.ideMode = params.ideMode ?? false;
+    this.ideClient = params.ideClient;
+  }
+
   async initialize(): Promise<void> {
     // Initialize centralized FileDiscoveryService
     this.getFileService();