From 5b4fc18339e9e59ecfce5ce007cf8e4d1b934813 Mon Sep 17 00:00:00 2001
From: Sehoon Shon <sshon@google.com>
Date: Mon, 23 Mar 2026 19:03:24 -0400
Subject: [PATCH] perf(core): parallelize tool discovery and background IDE
 client to speed up initialization

---
 packages/cli/src/core/initializer.test.ts |  3 +++
 packages/cli/src/core/initializer.ts      | 16 +++++++++++++---
 packages/core/src/config/config.ts        | 15 ++++++++++++---
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/packages/cli/src/core/initializer.test.ts b/packages/cli/src/core/initializer.test.ts
index e4fdb2cba5..9093ad54ee 100644
--- a/packages/cli/src/core/initializer.test.ts
+++ b/packages/cli/src/core/initializer.test.ts
@@ -105,6 +105,9 @@ describe('initializer', () => {
       mockSettings,
     );
 
+    // Wait for the background promise to resolve
+    await new Promise((resolve) => setTimeout(resolve, 0));
+
     expect(result).toEqual({
       authError: null,
       accountSuspensionInfo: null,
diff --git a/packages/cli/src/core/initializer.ts b/packages/cli/src/core/initializer.ts
index f27e9a9511..607129ae3e 100644
--- a/packages/cli/src/core/initializer.ts
+++ b/packages/cli/src/core/initializer.ts
@@ -13,6 +13,7 @@ import {
   StartSessionEvent,
   logCliConfiguration,
   startupProfiler,
+  debugLogger,
 } from '@google/gemini-cli-core';
 import { type LoadedSettings } from '../config/settings.js';
 import { performInitialAuth } from './auth.js';
@@ -55,9 +56,18 @@ export async function initializeApp(
   );
 
   if (config.getIdeMode()) {
-    const ideClient = await IdeClient.getInstance();
-    await ideClient.connect();
-    logIdeConnection(config, new IdeConnectionEvent(IdeConnectionType.START));
+    IdeClient.getInstance()
+      .then(async (ideClient) => {
+        await ideClient.connect();
+        logIdeConnection(
+          config,
+          new IdeConnectionEvent(IdeConnectionType.START),
+        );
+      })
+      .catch((e) => {
+        // We log locally if IDE connection setup fails in the background.
+        debugLogger.error('Failed to initialize IDE client:', e);
+      });
   }
 
   return {
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index e52a286e7a..5e9f6af653 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -1288,18 +1288,27 @@ export class Config implements McpContext, AgentLoopContext {
     // Initialize centralized FileDiscoveryService
     const discoverToolsHandle = startupProfiler.start('discover_tools');
     this.getFileService();
+
+    const discoveryPromises: Array<Promise<unknown>> = [];
+
     if (this.getCheckpointingEnabled()) {
-      await this.getGitService();
+      discoveryPromises.push(this.getGitService());
     }
+
     this._promptRegistry = new PromptRegistry();
     this._resourceRegistry = new ResourceRegistry();
 
     this.agentRegistry = new AgentRegistry(this);
-    await this.agentRegistry.initialize();
+    discoveryPromises.push(this.agentRegistry.initialize());
 
     coreEvents.on(CoreEvent.AgentsRefreshed, this.onAgentsRefreshed);
 
-    this._toolRegistry = await this.createToolRegistry();
+    const toolRegistryPromise = this.createToolRegistry().then((registry) => {
+      this._toolRegistry = registry;
+    });
+    discoveryPromises.push(toolRegistryPromise);
+
+    await Promise.all(discoveryPromises);
     discoverToolsHandle?.end();
     this.mcpClientManager = new McpClientManager(
       this.clientVersion,