3 files changed, 51 insertions, 13 deletions
diff --git a/packages/cli/src/config/config.test.ts b/packages/cli/src/config/config.test.ts
index 9f288372..a39278bc 100644
--- a/packages/cli/src/config/config.test.ts
+++ b/packages/cli/src/config/config.test.ts
@@ -82,29 +82,29 @@ describe('loadCliConfig', () => {
   it('should set showMemoryUsage to true when --memory flag is present', async () => {
     process.argv = ['node', 'script.js', '--show_memory_usage'];
     const settings: Settings = {};
-    const config = await loadCliConfig(settings);
-    expect(config.getShowMemoryUsage()).toBe(true);
+    const result = await loadCliConfig(settings);
+    expect(result.config.getShowMemoryUsage()).toBe(true);
   });
 
   it('should set showMemoryUsage to false when --memory flag is not present', async () => {
     process.argv = ['node', 'script.js'];
     const settings: Settings = {};
-    const config = await loadCliConfig(settings);
-    expect(config.getShowMemoryUsage()).toBe(false);
+    const result = await loadCliConfig(settings);
+    expect(result.config.getShowMemoryUsage()).toBe(false);
   });
 
   it('should set showMemoryUsage to false by default from settings if CLI flag is not present', async () => {
     process.argv = ['node', 'script.js'];
     const settings: Settings = { showMemoryUsage: false };
-    const config = await loadCliConfig(settings);
-    expect(config.getShowMemoryUsage()).toBe(false);
+    const result = await loadCliConfig(settings);
+    expect(result.config.getShowMemoryUsage()).toBe(false);
   });
 
   it('should prioritize CLI flag over settings for showMemoryUsage (CLI true, settings false)', async () => {
     process.argv = ['node', 'script.js', '--show_memory_usage'];
     const settings: Settings = { showMemoryUsage: false };
-    const config = await loadCliConfig(settings);
-    expect(config.getShowMemoryUsage()).toBe(true);
+    const result = await loadCliConfig(settings);
+    expect(result.config.getShowMemoryUsage()).toBe(true);
   });
 });
 
diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
index ee1c9d36..2429ad64 100644
--- a/packages/cli/src/config/config.ts
+++ b/packages/cli/src/config/config.ts
@@ -19,6 +19,10 @@ import {
 } from '@gemini-code/core';
 import { Settings } from './settings.js';
 import { readPackageUp } from 'read-package-up';
+import {
+  getEffectiveModel,
+  type EffectiveModelCheckResult,
+} from '../utils/modelCheck.js';
 
 // Simple console logger for now - replace with actual logger if available
 const logger = {
@@ -30,7 +34,8 @@ const logger = {
   error: (...args: any[]) => console.error('[ERROR]', ...args),
 };
 
-const DEFAULT_GEMINI_MODEL = 'gemini-2.5-pro-preview-05-06';
+export const DEFAULT_GEMINI_MODEL = 'gemini-2.5-pro-preview-05-06';
+export const DEFAULT_GEMINI_FLASH_MODEL = 'gemini-2.5-flash-preview-05-20';
 
 interface CliArgs {
   model: string | undefined;
@@ -114,7 +119,16 @@ export async function loadHierarchicalGeminiMemory(
   return loadServerHierarchicalMemory(currentWorkingDirectory, debugMode);
 }
 
-export async function loadCliConfig(settings: Settings): Promise<Config> {
+export interface LoadCliConfigResult {
+  config: Config;
+  modelWasSwitched: boolean;
+  originalModelBeforeSwitch?: string;
+  finalModel: string;
+}
+
+export async function loadCliConfig(
+  settings: Settings,
+): Promise<LoadCliConfigResult> {
   loadEnvironment();
 
   const geminiApiKey = process.env.GEMINI_API_KEY;
@@ -164,9 +178,27 @@ export async function loadCliConfig(settings: Settings): Promise<Config> {
   const apiKeyForServer = geminiApiKey || googleApiKey || '';
   const useVertexAI = hasGeminiApiKey ? false : undefined;
 
+  let modelToUse = argv.model || DEFAULT_GEMINI_MODEL;
+  let modelSwitched = false;
+  let originalModel: string | undefined = undefined;
+
+  if (apiKeyForServer) {
+    const checkResult: EffectiveModelCheckResult = await getEffectiveModel(
+      apiKeyForServer,
+      modelToUse,
+    );
+    if (checkResult.switched) {
+      modelSwitched = true;
+      originalModel = checkResult.originalModelIfSwitched;
+      modelToUse = checkResult.effectiveModel;
+    }
+  } else {
+    // logger.debug('API key not available during config load. Skipping model availability check.');
+  }
+
   const configParams: ConfigParameters = {
     apiKey: apiKeyForServer,
-    model: argv.model || DEFAULT_GEMINI_MODEL,
+    model: modelToUse,
     sandbox: argv.sandbox ?? settings.sandbox ?? argv.yolo ?? false,
     targetDir: process.cwd(),
     debugMode,
@@ -186,7 +218,13 @@ export async function loadCliConfig(settings: Settings): Promise<Config> {
       argv.show_memory_usage || settings.showMemoryUsage || false,
   };
 
-  return createServerConfig(configParams);
+  const config = createServerConfig(configParams);
+  return {
+    config,
+    modelWasSwitched: modelSwitched,
+    originalModelBeforeSwitch: originalModel,
+    finalModel: modelToUse,
+  };
 }
 
 async function createUserAgent(): Promise<string> {
diff --git a/packages/cli/src/config/settings.ts b/packages/cli/src/config/settings.ts
index 5d51ba15..6c14a6dc 100644
--- a/packages/cli/src/config/settings.ts
+++ b/packages/cli/src/config/settings.ts
@@ -7,7 +7,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import { homedir } from 'os';
-import { MCPServerConfig } from '@gemini-code/core/src/config/config.js';
+import { MCPServerConfig } from '@gemini-code/core';
 import stripJsonComments from 'strip-json-comments';
 import { DefaultLight } from '../ui/themes/default-light.js';
 import { DefaultDark } from '../ui/themes/default.js';