feat: Add startup profiler to measure and record application initialization phases. (#13638)

packages/cli/src/core/initializer.ts

@@ -12,6 +12,7 @@ import {
   type Config,
   StartSessionEvent,
   logCliConfiguration,
+  startupProfiler,
 } from '@google/gemini-cli-core';
 import { type LoadedSettings } from '../config/settings.js';
 import { performInitialAuth } from './auth.js';
@@ -35,10 +36,12 @@ export async function initializeApp(
   config: Config,
   settings: LoadedSettings,
 ): Promise<InitializationResult> {
+  const authHandle = startupProfiler.start('authenticate');
   const authError = await performInitialAuth(
     config,
     settings.merged.security?.auth?.selectedType,
   );
+  authHandle?.end();
   const themeError = validateTheme(settings);
 
   const shouldOpenAuthDialog =

packages/cli/src/gemini.tsx

@@ -56,6 +56,7 @@ import {
   enterAlternateScreen,
   disableLineWrapping,
   shouldEnterAlternateScreen,
+  startupProfiler,
   ExitCodes,
 } from '@google/gemini-cli-core';
 import {
@@ -281,6 +282,7 @@ export async function startInteractiveUI(
 }
 
 export async function main() {
+  const cliStartupHandle = startupProfiler.start('cli_startup');
   const cleanupStdio = patchStdio();
   registerSyncCleanup(() => {
     // This is needed to ensure we don't lose any buffered output.
@@ -289,7 +291,11 @@ export async function main() {
   });
 
   setupUnhandledRejectionHandler();
+  const loadSettingsHandle = startupProfiler.start('load_settings');
   const settings = loadSettings();
+  loadSettingsHandle?.end();
+
+  const migrateHandle = startupProfiler.start('migrate_settings');
   migrateDeprecatedSettings(
     settings,
     // Temporary extension manager only used during this non-interactive UI phase.
@@ -301,9 +307,12 @@ export async function main() {
       requestSetting: null,
     }),
   );
+  migrateHandle?.end();
   await cleanupCheckpoints();
 
+  const parseArgsHandle = startupProfiler.start('parse_arguments');
   const argv = await parseArguments(settings.merged);
+  parseArgsHandle?.end();
 
   // Check for invalid input combinations early to prevent crashes
   if (argv.promptInteractive && !process.stdin.isTTY) {
@@ -446,7 +455,9 @@ export async function main() {
   // to run Gemini CLI. It is now safe to perform expensive initialization that
   // may have side effects.
   {
+    const loadConfigHandle = startupProfiler.start('load_cli_config');
     const config = await loadCliConfig(settings.merged, sessionId, argv);
+    loadConfigHandle?.end();
 
     const policyEngine = config.getPolicyEngine();
     const messageBus = config.getMessageBus();
@@ -514,7 +525,9 @@ export async function main() {
     }
 
     setMaxSizedBoxDebugging(isDebugMode);
+    const initAppHandle = startupProfiler.start('initialize_app');
     const initializationResult = await initializeApp(config, settings);
+    initAppHandle?.end();
 
     if (
       settings.merged.security?.auth?.selectedType ===
@@ -556,6 +569,7 @@ export async function main() {
       }
     }
 
+    cliStartupHandle?.end();
     // Render UI, passing necessary config values. Check that there is no command line question.
     if (config.isInteractive()) {
       await startInteractiveUI(
@@ -570,6 +584,7 @@ export async function main() {
     }
 
     await config.initialize();
+    startupProfiler.flush(config);
 
     // If not a TTY, read from stdin
     // This is for cases where the user pipes input directly into the command

packages/cli/src/services/BuiltinCommandLoader.ts

@@ -8,6 +8,7 @@ import { isDevelopment } from '../utils/installationInfo.js';
 import type { ICommandLoader } from './types.js';
 import type { SlashCommand } from '../ui/commands/types.js';
 import type { Config } from '@google/gemini-cli-core';
+import { startupProfiler } from '@google/gemini-cli-core';
 import { aboutCommand } from '../ui/commands/aboutCommand.js';
 import { authCommand } from '../ui/commands/authCommand.js';
 import { bugCommand } from '../ui/commands/bugCommand.js';
@@ -56,6 +57,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
    * @returns A promise that resolves to an array of `SlashCommand` objects.
    */
   async loadCommands(_signal: AbortSignal): Promise<SlashCommand[]> {
+    const handle = startupProfiler.start('load_builtin_commands');
     const allDefinitions: Array<SlashCommand | null> = [
       aboutCommand,
       authCommand,
@@ -92,7 +94,7 @@ export class BuiltinCommandLoader implements ICommandLoader {
       setupGithubCommand,
       terminalSetupCommand,
     ];
-
+    handle?.end();
     return allDefinitions.filter((cmd): cmd is SlashCommand => cmd !== null);
   }
 }

packages/cli/src/ui/AppContainer.tsx

@@ -58,6 +58,7 @@ import {
   enableMouseEvents,
   disableLineWrapping,
   shouldEnterAlternateScreen,
+  startupProfiler,
 } from '@google/gemini-cli-core';
 import { validateAuthMethod } from '../config/auth.js';
 import process from 'node:process';
@@ -282,6 +283,7 @@ export const AppContainer = (props: AppContainerProps) => {
       // handled by the global catch.
       await config.initialize();
       setConfigInitialized(true);
+      startupProfiler.flush(config);
     })();
     registerCleanup(async () => {
       // Turn off mouse scroll.

packages/cli/src/zed-integration/zedIntegration.ts

@@ -30,6 +30,7 @@ import {
   debugLogger,
   ReadManyFilesTool,
   getEffectiveModel,
+  startupProfiler,
 } from '@google/gemini-cli-core';
 import * as acp from './acp.js';
 import { AcpFileSystemService } from './fileSystemService.js';
@@ -189,6 +190,7 @@ export class GeminiAgent {
     const config = await loadCliConfig(settings, sessionId, this.argv, cwd);
 
     await config.initialize();
+    startupProfiler.flush(config);
     return config;
   }