refactor: update authentication handling and model configuration

- Enhanced authentication method validation in `auth.ts` and `auth.test.ts`.
- Introduced new model provider configuration logic
- Updated environment variable handling for various auth types.
- Removed deprecated utility functions and tests related to fallback mechanisms.

packages/cli/src/config/auth.ts

@@ -1,24 +1,97 @@
 /**
  * @license
- * Copyright 2025 Google LLC
+ * Copyright 2025 Qwen Team
  * SPDX-License-Identifier: Apache-2.0
  */
 
 import { AuthType } from '@qwen-code/qwen-code-core';
-import { loadEnvironment, loadSettings } from './settings.js';
+import type {
+  ModelProvidersConfig,
+  ProviderModelConfig,
+} from '@qwen-code/qwen-code-core';
+import { loadEnvironment, loadSettings, type Settings } from './settings.js';
+
+/**
+ * Default environment variable names for each auth type
+ */
+const DEFAULT_ENV_KEYS: Record<string, string> = {
+  [AuthType.USE_OPENAI]: 'OPENAI_API_KEY',
+  [AuthType.USE_ANTHROPIC]: 'ANTHROPIC_API_KEY',
+  [AuthType.USE_GEMINI]: 'GEMINI_API_KEY',
+  [AuthType.USE_VERTEX_AI]: 'GOOGLE_API_KEY',
+};
+
+/**
+ * Find model configuration from modelProviders by authType and modelId
+ */
+function findModelConfig(
+  modelProviders: ModelProvidersConfig | undefined,
+  authType: string,
+  modelId: string | undefined,
+): ProviderModelConfig | undefined {
+  if (!modelProviders || !modelId) {
+    return undefined;
+  }
+
+  const models = modelProviders[authType];
+  if (!Array.isArray(models)) {
+    return undefined;
+  }
+
+  return models.find((m) => m.id === modelId);
+}
+
+/**
+ * Check if API key is available for the given auth type and model configuration.
+ * Prioritizes custom envKey from modelProviders over default environment variables.
+ */
+function hasApiKeyForAuth(
+  authType: string,
+  settings: Settings,
+): { hasKey: boolean; checkedEnvKey: string | undefined } {
+  const modelProviders = settings.modelProviders as
+    | ModelProvidersConfig
+    | undefined;
+  const modelId = settings.model?.name;
+
+  // Try to find model-specific envKey from modelProviders
+  const modelConfig = findModelConfig(modelProviders, authType, modelId);
+  if (modelConfig?.envKey) {
+    const hasKey = !!process.env[modelConfig.envKey];
+    return { hasKey, checkedEnvKey: modelConfig.envKey };
+  }
+
+  // Fallback to default environment variable
+  const defaultEnvKey = DEFAULT_ENV_KEYS[authType];
+  if (defaultEnvKey) {
+    const hasKey = !!process.env[defaultEnvKey];
+    return { hasKey, checkedEnvKey: defaultEnvKey };
+  }
+
+  // Also check settings.security.auth.apiKey as fallback
+  if (settings.security?.auth?.apiKey) {
+    return { hasKey: true, checkedEnvKey: undefined };
+  }
+
+  return { hasKey: false, checkedEnvKey: undefined };
+}
 
 export function validateAuthMethod(authMethod: string): string | null {
   const settings = loadSettings();
   loadEnvironment(settings.merged);
 
   if (authMethod === AuthType.USE_OPENAI) {
-    const hasApiKey =
-      process.env['OPENAI_API_KEY'] || settings.merged.security?.auth?.apiKey;
-    if (!hasApiKey) {
+    const { hasKey, checkedEnvKey } = hasApiKeyForAuth(
+      authMethod,
+      settings.merged,
+    );
+    if (!hasKey) {
+      const envKeyHint = checkedEnvKey
+        ? `'${checkedEnvKey}'`
+        : "'OPENAI_API_KEY' (or configure modelProviders[].envKey)";
       return (
         'Missing API key for OpenAI-compatible auth. ' +
-        "Set settings.security.auth.apiKey, or set the 'OPENAI_API_KEY' environment variable. " +
-        'If you configured a model in settings.modelProviders with an envKey, set that env var as well.'
+        `Set settings.security.auth.apiKey, or set the ${envKeyHint} environment variable.`
       );
     }
     return null;
@@ -31,31 +104,50 @@ export function validateAuthMethod(authMethod: string): string | null {
   }
 
   if (authMethod === AuthType.USE_ANTHROPIC) {
-    const hasApiKey = process.env['ANTHROPIC_API_KEY'];
-    if (!hasApiKey) {
-      return 'ANTHROPIC_API_KEY environment variable not found.';
+    const { hasKey, checkedEnvKey } = hasApiKeyForAuth(
+      authMethod,
+      settings.merged,
+    );
+    if (!hasKey) {
+      const envKeyHint = checkedEnvKey || 'ANTHROPIC_API_KEY';
+      return `${envKeyHint} environment variable not found.`;
     }
 
-    const hasBaseUrl = process.env['ANTHROPIC_BASE_URL'];
+    // Check baseUrl - can come from modelProviders or environment
+    const modelProviders = settings.merged.modelProviders as
+      | ModelProvidersConfig
+      | undefined;
+    const modelId = settings.merged.model?.name;
+    const modelConfig = findModelConfig(modelProviders, authMethod, modelId);
+    const hasBaseUrl =
+      modelConfig?.baseUrl || process.env['ANTHROPIC_BASE_URL'];
     if (!hasBaseUrl) {
-      return 'ANTHROPIC_BASE_URL environment variable not found.';
+      return 'ANTHROPIC_BASE_URL environment variable not found (or configure modelProviders[].baseUrl).';
     }
 
     return null;
   }
 
   if (authMethod === AuthType.USE_GEMINI) {
-    const hasApiKey = process.env['GEMINI_API_KEY'];
-    if (!hasApiKey) {
-      return 'GEMINI_API_KEY environment variable not found. Please set it in your .env file or environment variables.';
+    const { hasKey, checkedEnvKey } = hasApiKeyForAuth(
+      authMethod,
+      settings.merged,
+    );
+    if (!hasKey) {
+      const envKeyHint = checkedEnvKey || 'GEMINI_API_KEY';
+      return `${envKeyHint} environment variable not found. Please set it in your .env file or environment variables.`;
     }
     return null;
   }
 
   if (authMethod === AuthType.USE_VERTEX_AI) {
-    const hasApiKey = process.env['GOOGLE_API_KEY'];
-    if (!hasApiKey) {
-      return 'GOOGLE_API_KEY environment variable not found. Please set it in your .env file or environment variables.';
+    const { hasKey, checkedEnvKey } = hasApiKeyForAuth(
+      authMethod,
+      settings.merged,
+    );
+    if (!hasKey) {
+      const envKeyHint = checkedEnvKey || 'GOOGLE_API_KEY';
+      return `${envKeyHint} environment variable not found. Please set it in your .env file or environment variables.`;
     }
 
     process.env['GOOGLE_GENAI_USE_VERTEXAI'] = 'true';