diff --git a/packages/core/src/agent/config-loader.ts b/packages/core/src/agent/config-loader.ts
index 74755f8..00c989a 100644
--- a/packages/core/src/agent/config-loader.ts
+++ b/packages/core/src/agent/config-loader.ts
@@ -1,67 +1,39 @@
 import * as fs from 'fs';
 import * as path from 'path';
+import * as os from 'os';
 import type { AgentConfigFile } from './types.js';
 
 /**
- * 配置文件搜索路径
+ * 全局配置目录
  */
-const CONFIG_PATHS = [
-  '.ai-assist/agents.yaml',
-  '.ai-assist/agents.yml',
-  '.ai-assist/agents.json',
-  '.ai-assist.yaml',
-  '.ai-assist.yml',
-];
-
-/**
- * 解析 YAML 内容
- */
-async function parseYaml(content: string): Promise<unknown> {
-  try {
-    const yaml = await import('js-yaml');
-    return yaml.load(content);
-  } catch {
-    console.warn('解析 YAML 配置文件失败');
-    return null;
-  }
-}
+const GLOBAL_CONFIG_DIR = path.join(os.homedir(), '.ai-terminal-assistant');
 
 /**
  * 加载用户自定义 Agent 配置
- * @param workdir 工作目录
+ * 从 ~/.ai-terminal-assistant/agents.json 读取
+ *
+ * @param _workdir 工作目录（保留参数以兼容现有调用，但不再使用）
  * @returns 配置对象或 null
  */
-export async function loadAgentConfig(workdir: string): Promise<AgentConfigFile | null> {
-  for (const configPath of CONFIG_PATHS) {
-    const fullPath = path.join(workdir, configPath);
+export async function loadAgentConfig(_workdir: string): Promise<AgentConfigFile | null> {
+  const configPath = path.join(GLOBAL_CONFIG_DIR, 'agents.json');
 
-    try {
-      if (!fs.existsSync(fullPath)) {
-        continue;
-      }
-
-      const content = await fs.promises.readFile(fullPath, 'utf-8');
-
-      let config: unknown;
-
-      if (configPath.endsWith('.json')) {
-        config = JSON.parse(content);
-      } else if (configPath.endsWith('.yaml') || configPath.endsWith('.yml')) {
-        config = await parseYaml(content);
-        if (!config) continue;
-      } else {
-        continue;
-      }
-
-      // 验证配置格式
-      if (isValidAgentConfig(config)) {
-        return config;
-      } else {
-        console.warn(`Agent 配置格式无效: ${fullPath}`);
-      }
-    } catch (error) {
-      console.warn(`加载 Agent 配置失败: ${fullPath}`, error);
+  try {
+    if (!fs.existsSync(configPath)) {
+      return null;
     }
+
+    const content = await fs.promises.readFile(configPath, 'utf-8');
+    const config = JSON.parse(content);
+
+    // 验证配置格式
+    if (isValidAgentConfig(config)) {
+      return config;
+    } else {
+      console.warn(`Agent 配置格式无效: ${configPath}`);
+    }
+  } catch (error) {
+    console.warn(`加载 Agent 配置失败: ${configPath}`, error);
   }
 
   return null;
@@ -92,39 +64,24 @@ function isValidAgentConfig(config: unknown): config is AgentConfigFile {
 
 /**
  * 保存 Agent 配置到文件
- * @param workdir 工作目录
+ * 保存到 ~/.ai-terminal-assistant/agents.json
+ *
+ * @param _workdir 工作目录（保留参数以兼容现有调用，但不再使用）
  * @param config 配置对象
- * @param format 文件格式
+ * @param _format 文件格式（保留参数以兼容现有调用，但只使用 json）
  */
 export async function saveAgentConfig(
-  workdir: string,
+  _workdir: string,
   config: AgentConfigFile,
-  format: 'json' | 'yaml' = 'json'
+  _format: 'json' | 'yaml' = 'json'
 ): Promise<void> {
-  const dir = path.join(workdir, '.ai-assist');
-
   // 确保目录存在
-  if (!fs.existsSync(dir)) {
-    await fs.promises.mkdir(dir, { recursive: true });
+  if (!fs.existsSync(GLOBAL_CONFIG_DIR)) {
+    await fs.promises.mkdir(GLOBAL_CONFIG_DIR, { recursive: true });
   }
 
-  const filename = format === 'json' ? 'agents.json' : 'agents.yaml';
-  const fullPath = path.join(dir, filename);
-
-  let content: string;
-
-  if (format === 'json') {
-    content = JSON.stringify(config, null, 2);
-  } else {
-    try {
-      const yaml = await import('js-yaml');
-      content = yaml.dump(config, { indent: 2, lineWidth: 120 });
-    } catch {
-      // 回退到 JSON
-      content = JSON.stringify(config, null, 2);
-      console.warn('保存 YAML 失败，已保存为 JSON 格式');
-    }
-  }
+  const fullPath = path.join(GLOBAL_CONFIG_DIR, 'agents.json');
+  const content = JSON.stringify(config, null, 2);
 
   await fs.promises.writeFile(fullPath, content, 'utf-8');
 }
diff --git a/packages/core/src/agent/types.ts b/packages/core/src/agent/types.ts
index e36b569..c15b912 100644
--- a/packages/core/src/agent/types.ts
+++ b/packages/core/src/agent/types.ts
@@ -109,16 +109,26 @@ export interface AgentInfo {
   maxSteps?: number;
 }
 
+/**
+ * Agent 配置文件默认配置
+ */
+export interface AgentConfigFileDefaults {
+  /** 最大执行步数 */
+  maxSteps?: number;
+  /** 默认模型配置（全局 Provider/Model 选择） */
+  model?: AgentModelConfig;
+  /** Vision 模型配置（用于图片理解） */
+  vision?: AgentModelConfig;
+  /** 默认权限配置 */
+  permission?: AgentPermission;
+}
+
 /**
  * Agent 配置文件格式（用户自定义）
  */
 export interface AgentConfigFile {
   /** 全局默认配置 */
-  defaults?: {
-    maxSteps?: number;
-    model?: AgentModelConfig;
-    permission?: AgentPermission;
-  };
+  defaults?: AgentConfigFileDefaults;
   /** Agent 定义 */
   agents?: Record<string, Omit<AgentInfo, 'name'>>;
 }
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index c28b0e1..bff5667 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -10,7 +10,7 @@ export {
 } from './core/doom-loop.js';
 export type { DoomLoopDetector } from './core/doom-loop.js';
 export { toolRegistry, todoManager, initTaskContext, updateTaskDescription, updateSkillDescription } from './tools/index.js';
-export { loadConfig, saveConfig, getConfig, loadVisionConfig, ConfigurationError } from './utils/config.js';
+export { loadConfig, loadVisionConfig, buildConfigFromModelConfig, ConfigurationError } from './utils/config.js';
 export type { VisionConfig } from './utils/config.js';
 
 // Context compression
diff --git a/packages/core/src/tools/web/web_extract.ts b/packages/core/src/tools/web/web_extract.ts
index d123c96..f435d5f 100644
--- a/packages/core/src/tools/web/web_extract.ts
+++ b/packages/core/src/tools/web/web_extract.ts
@@ -2,7 +2,6 @@ import { tavily } from '@tavily/core';
 import type { ToolResult } from '../../types/index.js';
 import type { ToolWithMetadata } from '../types.js';
 import { loadDescription } from '../load_description.js';
-import { getConfig } from '../../utils/config.js';
 import { getPermissionManager } from '../../permission/index.js';
 
 export const webExtractTool: ToolWithMetadata = {
@@ -73,15 +72,14 @@ export const webExtractTool: ToolWithMetadata = {
       };
     }
 
-    // 获取 Tavily API Key
-    const config = getConfig();
-    const apiKey = process.env.TAVILY_API_KEY || config.tavilyApiKey;
+    // 获取 Tavily API Key（从环境变量）
+    const apiKey = process.env.TAVILY_API_KEY;
 
     if (!apiKey) {
       return {
         success: false,
         output: '',
-        error: '未配置 Tavily API Key。请设置环境变量 TAVILY_API_KEY 或在配置文件中添加 tavilyApiKey。',
+        error: '未配置 Tavily API Key。请设置环境变量 TAVILY_API_KEY。',
       };
     }
 
diff --git a/packages/core/src/tools/web/web_search.ts b/packages/core/src/tools/web/web_search.ts
index 05e51fc..aaadef2 100644
--- a/packages/core/src/tools/web/web_search.ts
+++ b/packages/core/src/tools/web/web_search.ts
@@ -2,7 +2,6 @@ import { tavily } from '@tavily/core';
 import type { ToolResult } from '../../types/index.js';
 import type { ToolWithMetadata } from '../types.js';
 import { loadDescription } from '../load_description.js';
-import { getConfig } from '../../utils/config.js';
 import { getPermissionManager } from '../../permission/index.js';
 
 export const webSearchTool: ToolWithMetadata = {
@@ -75,15 +74,14 @@ export const webSearchTool: ToolWithMetadata = {
       };
     }
 
-    // 获取 Tavily API Key
-    const config = getConfig();
-    const apiKey = process.env.TAVILY_API_KEY || config.tavilyApiKey;
+    // 获取 Tavily API Key（从环境变量）
+    const apiKey = process.env.TAVILY_API_KEY;
 
     if (!apiKey) {
       return {
         success: false,
         output: '',
-        error: '未配置 Tavily API Key。请设置环境变量 TAVILY_API_KEY 或在配置文件中添加 tavilyApiKey。',
+        error: '未配置 Tavily API Key。请设置环境变量 TAVILY_API_KEY。',
       };
     }
 
diff --git a/packages/core/src/utils/config.ts b/packages/core/src/utils/config.ts
index c31a9db..eeba446 100644
--- a/packages/core/src/utils/config.ts
+++ b/packages/core/src/utils/config.ts
@@ -1,8 +1,14 @@
-import * as fs from 'fs';
-import * as path from 'path';
-import * as os from 'os';
+/**
+ * Agent 配置加载
+ *
+ * 从 agents.json 的 defaults.model 读取全局模型配置
+ * 从 providers.json 读取 API Key 和 baseUrl
+ */
+
 import type { AgentConfig, ProviderType } from '../types/index.js';
 import { providerRegistry, resolveApiKey } from '../provider/index.js';
+import { agentRegistry } from '../agent/registry.js';
+import type { AgentModelConfig } from '../agent/types.js';
 
 /**
  * 配置错误异常
@@ -21,32 +27,6 @@ export class ConfigurationError extends Error {
   }
 }
 
-const CONFIG_DIR = path.join(os.homedir(), '.ai-terminal-assistant');
-const CONFIG_FILE = path.join(CONFIG_DIR, 'config.json');
-
-interface StoredConfig {
-  provider?: ProviderType;
-  model?: string;
-  maxTokens?: number;
-  tavilyApiKey?: string;
-  /** 自定义 API 基础 URL（用于 OpenAI 兼容服务，如阿里云百炼） */
-  baseUrl?: string;
-  // Vision 配置
-  visionProvider?: ProviderType;
-  visionModel?: string;
-  /** Vision 专用的 Base URL（用于 OpenAI 兼容的 Vision 服务） */
-  visionBaseUrl?: string;
-}
-
-// Vision 配置接口
-export interface VisionConfig {
-  provider: ProviderType;
-  apiKey: string;
-  model: string;
-  /** 自定义 Base URL（用于 OpenAI 兼容的 Vision 服务） */
-  baseUrl?: string;
-}
-
 // 默认模型配置
 const DEFAULT_MODELS: Record<ProviderType, string> = {
   anthropic: 'claude-sonnet-4-20250514',
@@ -54,13 +34,6 @@ const DEFAULT_MODELS: Record<ProviderType, string> = {
   openai: 'gpt-4o',
 };
 
-// 默认 Vision 模型（需要支持图片理解）
-const DEFAULT_VISION_MODELS: Record<ProviderType, string> = {
-  anthropic: 'claude-sonnet-4-20250514',
-  deepseek: 'deepseek-chat', // DeepSeek 暂不支持 vision，占位用
-  openai: 'gpt-4o',
-};
-
 // 默认系统提示词
 const DEFAULT_SYSTEM_PROMPT = `你是一个运行在终端中的 AI 编程助手。你可以帮助用户：
 - 读取和写入文件
@@ -81,116 +54,159 @@ const DEFAULT_SYSTEM_PROMPT = `你是一个运行在终端中的 AI 编程助手
 当前工作目录: ${process.cwd()}
 操作系统: ${process.platform}`;
 
-// 获取原始配置（包含所有字段）
-export function getConfig(): StoredConfig {
-  if (fs.existsSync(CONFIG_FILE)) {
-    try {
-      const content = fs.readFileSync(CONFIG_FILE, 'utf-8');
-      return JSON.parse(content);
-    } catch {
-      return {};
+/**
+ * 查找第一个已配置 API Key 的 Provider
+ * 作为未配置 defaults.model 时的 fallback
+ */
+function findFirstConfiguredProvider(): ProviderType | null {
+  const providers: ProviderType[] = ['anthropic', 'openai', 'deepseek'];
+
+  for (const providerId of providers) {
+    const config = providerRegistry.getConfig(providerId);
+    const apiKey = resolveApiKey(config);
+    if (apiKey) {
+      return providerId;
     }
   }
-  return {};
+
+  return null;
 }
 
-// 加载配置
+/**
+ * 加载 Agent 配置
+ *
+ * 配置来源优先级：
+ * 1. agents.json 的 defaults.model（用户配置的全局默认模型）
+ * 2. 第一个已配置 API Key 的 Provider（fallback）
+ * 3. 抛出 ConfigurationError（无可用配置）
+ */
 export function loadConfig(): AgentConfig {
-  // 从配置文件读取
-  const storedConfig = getConfig();
+  // 1. 从 AgentRegistry 获取 defaults.model 配置
+  const globalConfig = agentRegistry.getGlobalConfig();
+  const modelConfig = globalConfig?.model;
 
-  // 检查是否配置了 provider
-  const hasProviderConfig = !!storedConfig.provider;
-  const finalProvider = storedConfig.provider || 'anthropic';
+  // 2. 确定 provider（优先使用配置，否则使用第一个有 API Key 的 provider）
+  let provider: ProviderType;
+  let model: string;
 
-  // 通过 ProviderRegistry 获取 API Key
-  const providerConfig = providerRegistry.getConfig(finalProvider);
-  const finalApiKey = resolveApiKey(providerConfig);
-
-  if (!finalApiKey) {
-    // 根据是否已选择 provider 给出不同的提示
-    const message = hasProviderConfig
-      ? `请在 Providers 面板配置 ${finalProvider} 的 API Key`
-      : '请先在 Providers 面板选择并配置一个模型提供商';
-    throw new ConfigurationError(message, finalProvider, 'apiKey');
+  if (modelConfig?.provider) {
+    // 用户配置了 defaults.model.provider
+    provider = modelConfig.provider;
+    model = modelConfig.model || DEFAULT_MODELS[provider];
+  } else {
+    // 未配置，尝试找第一个有 API Key 的 provider
+    const fallbackProvider = findFirstConfiguredProvider();
+    if (!fallbackProvider) {
+      throw new ConfigurationError(
+        '请先在 Providers 面板配置一个模型提供商的 API Key',
+        'unknown',
+        'apiKey'
+      );
+    }
+    provider = fallbackProvider;
+    model = DEFAULT_MODELS[provider];
   }
 
-  // 确定模型
-  const finalModel = storedConfig.model || DEFAULT_MODELS[finalProvider];
+  // 3. 从 ProviderRegistry 获取 API Key 和 baseUrl
+  const providerConfig = providerRegistry.getConfig(provider);
+  const apiKey = resolveApiKey(providerConfig);
 
-  // 确定 baseUrl
-  const finalBaseUrl = storedConfig.baseUrl || providerConfig?.baseUrl;
+  if (!apiKey) {
+    throw new ConfigurationError(
+      `请在 Providers 面板配置 ${provider} 的 API Key`,
+      provider,
+      'apiKey'
+    );
+  }
 
-  // 获取模型的 contextWindow（从 ProviderRegistry 查询）
-  const modelInfo = providerRegistry.getModelInfo(finalProvider, finalModel);
+  // 4. 获取模型的 contextWindow
+  const modelInfo = providerRegistry.getModelInfo(provider, model);
   const contextWindow = modelInfo?.contextWindow;
 
+  // 5. 获取 maxTokens（从 modelConfig 或默认值）
+  const maxTokens = modelConfig?.maxTokens || 4096;
+
   return {
-    provider: finalProvider,
-    apiKey: finalApiKey,
-    model: finalModel,
-    maxTokens: storedConfig.maxTokens || 4096,
+    provider,
+    apiKey,
+    model,
+    maxTokens,
     systemPrompt: DEFAULT_SYSTEM_PROMPT,
-    baseUrl: finalBaseUrl,
+    baseUrl: providerConfig?.baseUrl,
     contextWindow,
   };
 }
 
+// Vision 配置接口
+export interface VisionConfig {
+  provider: ProviderType;
+  apiKey: string;
+  model: string;
+  baseUrl?: string;
+}
+
 /**
  * 加载 Vision 配置
+ *
+ * 从 agents.json 的 defaults.vision 读取配置
  * Vision 用于图片理解，当主模型不支持 vision 时使用
- * 通过 ProviderRegistry 获取 API Key
  */
 export function loadVisionConfig(): VisionConfig | null {
-  // 从配置文件读取
-  const storedConfig = getConfig();
+  // 从 AgentRegistry 获取 defaults.vision 配置
+  const globalConfig = agentRegistry.getGlobalConfig();
+  const visionConfig = globalConfig?.vision;
 
-  // 确定 vision provider（默认使用 anthropic，因为 Claude 支持 vision）
-  const finalProvider = storedConfig.visionProvider || 'anthropic';
-
-  // 通过 ProviderRegistry 获取 API Key
-  const providerConfig = providerRegistry.getConfig(finalProvider);
-  const finalApiKey = resolveApiKey(providerConfig);
-
-  // 如果没有 API Key，返回 null
-  if (!finalApiKey) {
+  if (!visionConfig?.provider) {
+    // 未配置 vision，返回 null
     return null;
   }
 
-  // 确定模型
-  const finalModel = storedConfig.visionModel || DEFAULT_VISION_MODELS[finalProvider];
+  // 从 ProviderRegistry 获取 API Key
+  const providerConfig = providerRegistry.getConfig(visionConfig.provider);
+  const apiKey = resolveApiKey(providerConfig);
 
-  // 确定 baseUrl
-  const finalBaseUrl = storedConfig.visionBaseUrl || providerConfig?.baseUrl;
+  if (!apiKey) {
+    // 没有 API Key，返回 null
+    return null;
+  }
+
+  // 确定模型（使用配置的或默认值）
+  const model = visionConfig.model || DEFAULT_MODELS[visionConfig.provider];
 
   return {
-    provider: finalProvider,
-    apiKey: finalApiKey,
-    model: finalModel,
-    baseUrl: finalBaseUrl,
+    provider: visionConfig.provider,
+    apiKey,
+    model,
+    baseUrl: providerConfig?.baseUrl,
   };
 }
 
-// 保存配置
-export function saveConfig(config: Partial<StoredConfig>): void {
-  // 确保目录存在
-  if (!fs.existsSync(CONFIG_DIR)) {
-    fs.mkdirSync(CONFIG_DIR, { recursive: true });
+/**
+ * 从 AgentModelConfig 构建完整配置
+ * 用于 Task 工具动态构建 Agent 配置
+ */
+export function buildConfigFromModelConfig(modelConfig: AgentModelConfig): AgentConfig | null {
+  if (!modelConfig.provider) {
+    return null;
   }
 
-  // 读取现有配置
-  let existingConfig: StoredConfig = {};
-  if (fs.existsSync(CONFIG_FILE)) {
-    try {
-      const content = fs.readFileSync(CONFIG_FILE, 'utf-8');
-      existingConfig = JSON.parse(content);
-    } catch {
-      // 忽略
-    }
+  const providerConfig = providerRegistry.getConfig(modelConfig.provider);
+  const apiKey = resolveApiKey(providerConfig);
+
+  if (!apiKey) {
+    return null;
   }
 
-  // 合并并保存
-  const newConfig = { ...existingConfig, ...config };
-  fs.writeFileSync(CONFIG_FILE, JSON.stringify(newConfig, null, 2));
+  const model = modelConfig.model || DEFAULT_MODELS[modelConfig.provider];
+  const modelInfo = providerRegistry.getModelInfo(modelConfig.provider, model);
+
+  return {
+    provider: modelConfig.provider,
+    apiKey,
+    model,
+    maxTokens: modelConfig.maxTokens || 4096,
+    systemPrompt: DEFAULT_SYSTEM_PROMPT,
+    baseUrl: providerConfig?.baseUrl,
+    contextWindow: modelInfo?.contextWindow,
+  };
 }
-
diff --git a/packages/core/tests/unit/tools/web/web_extract.test.ts b/packages/core/tests/unit/tools/web/web_extract.test.ts
index 8d4b306..ba9c6f1 100644
--- a/packages/core/tests/unit/tools/web/web_extract.test.ts
+++ b/packages/core/tests/unit/tools/web/web_extract.test.ts
@@ -8,12 +8,8 @@ vi.mock('@tavily/core', () => ({
   })),
 }));
 
-// Mock config
-vi.mock('../../../../src/utils/config.js', () => ({
-  getConfig: vi.fn(() => ({
-    tavilyApiKey: 'test-api-key',
-  })),
-}));
+// Mock environment variable for Tavily API Key
+vi.stubEnv('TAVILY_API_KEY', 'test-api-key');
 
 // Mock permission manager
 vi.mock('../../../../src/permission/index.js', () => ({
@@ -32,7 +28,6 @@ vi.mock('../../../../src/tools/load_description.js', () => ({
 
 import { webExtractTool } from '../../../../src/tools/web/web_extract.js';
 import { getPermissionManager } from '../../../../src/permission/index.js';
-import { getConfig } from '../../../../src/utils/config.js';
 
 describe('webExtractTool - 网页内容提取工具', () => {
   beforeEach(() => {
@@ -198,9 +193,7 @@ describe('webExtractTool - 网页内容提取工具', () => {
     });
 
     it('无 API Key 返回错误', async () => {
-      vi.mocked(getConfig).mockReturnValue({} as any);
-      const originalEnv = process.env.TAVILY_API_KEY;
-      delete process.env.TAVILY_API_KEY;
+      vi.unstubAllEnvs();
 
       const result = await webExtractTool.execute({
         urls: ['https://example.com'],
@@ -209,7 +202,7 @@ describe('webExtractTool - 网页内容提取工具', () => {
       expect(result.success).toBe(false);
       expect(result.error).toContain('未配置 Tavily API Key');
 
-      process.env.TAVILY_API_KEY = originalEnv;
+      vi.stubEnv('TAVILY_API_KEY', 'test-api-key');
     });
 
     it('权限被拒绝时返回错误', async () => {
diff --git a/packages/core/tests/unit/tools/web/web_search.test.ts b/packages/core/tests/unit/tools/web/web_search.test.ts
index b0ae5ed..7cdccfa 100644
--- a/packages/core/tests/unit/tools/web/web_search.test.ts
+++ b/packages/core/tests/unit/tools/web/web_search.test.ts
@@ -8,12 +8,8 @@ vi.mock('@tavily/core', () => ({
   })),
 }));
 
-// Mock config
-vi.mock('../../../../src/utils/config.js', () => ({
-  getConfig: vi.fn(() => ({
-    tavilyApiKey: 'test-api-key',
-  })),
-}));
+// Mock environment variable for Tavily API Key
+vi.stubEnv('TAVILY_API_KEY', 'test-api-key');
 
 // Mock permission manager
 vi.mock('../../../../src/permission/index.js', () => ({
@@ -32,7 +28,6 @@ vi.mock('../../../../src/tools/load_description.js', () => ({
 
 import { webSearchTool } from '../../../../src/tools/web/web_search.js';
 import { getPermissionManager } from '../../../../src/permission/index.js';
-import { getConfig } from '../../../../src/utils/config.js';
 
 describe('webSearchTool - 网络搜索工具', () => {
   beforeEach(() => {
@@ -131,16 +126,14 @@ describe('webSearchTool - 网络搜索工具', () => {
     });
 
     it('无 API Key 返回错误', async () => {
-      vi.mocked(getConfig).mockReturnValue({} as any);
-      const originalEnv = process.env.TAVILY_API_KEY;
-      delete process.env.TAVILY_API_KEY;
+      vi.unstubAllEnvs();
 
       const result = await webSearchTool.execute({ query: 'test' });
 
       expect(result.success).toBe(false);
       expect(result.error).toContain('未配置 Tavily API Key');
 
-      process.env.TAVILY_API_KEY = originalEnv;
+      vi.stubEnv('TAVILY_API_KEY', 'test-api-key');
     });
 
     it('权限被拒绝时返回错误', async () => {
diff --git a/packages/core/tests/unit/utils/config-extended.test.ts b/packages/core/tests/unit/utils/config-extended.test.ts
deleted file mode 100644
index 88280ee..0000000
--- a/packages/core/tests/unit/utils/config-extended.test.ts
+++ /dev/null
@@ -1,243 +0,0 @@
-import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
-import * as fs from 'fs';
-import * as os from 'os';
-import * as path from 'path';
-
-// Mock fs module
-vi.mock('fs', () => ({
-  existsSync: vi.fn(),
-  readFileSync: vi.fn(),
-  writeFileSync: vi.fn(),
-  mkdirSync: vi.fn(),
-}));
-
-// Mock provider registry
-vi.mock('../../../src/provider/index.js', () => ({
-  providerRegistry: {
-    getInfo: vi.fn(),
-    getConfig: vi.fn(),
-  },
-  resolveApiKey: vi.fn(),
-}));
-
-// Mock process.exit
-const mockExit = vi.spyOn(process, 'exit').mockImplementation(() => {
-  throw new Error('process.exit called');
-});
-
-// Mock console.error
-const mockConsoleError = vi.spyOn(console, 'error').mockImplementation(() => {});
-
-describe('Config - 配置管理扩展测试', () => {
-  const CONFIG_DIR = path.join(os.homedir(), '.ai-terminal-assistant');
-  const CONFIG_FILE = path.join(CONFIG_DIR, 'config.json');
-
-  beforeEach(() => {
-    vi.clearAllMocks();
-  });
-
-  afterEach(() => {
-    mockExit.mockClear();
-    mockConsoleError.mockClear();
-  });
-
-  describe('getConfig - 获取原始配置', () => {
-    it('配置文件不存在返回空对象', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { getConfig } = await import('../../../src/utils/config.js');
-
-      const config = getConfig();
-      expect(config).toEqual({});
-    });
-
-    it('配置文件存在返回解析后的内容', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-        model: 'claude-sonnet-4-20250514',
-      }));
-
-      vi.resetModules();
-      const { getConfig } = await import('../../../src/utils/config.js');
-
-      const config = getConfig();
-      expect(config.provider).toBe('anthropic');
-      expect(config.model).toBe('claude-sonnet-4-20250514');
-    });
-
-    it('配置文件解析错误返回空对象', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue('invalid json');
-
-      vi.resetModules();
-      const { getConfig } = await import('../../../src/utils/config.js');
-
-      const config = getConfig();
-      expect(config).toEqual({});
-    });
-  });
-
-  describe('loadConfig - 加载配置', () => {
-    it('通过 ProviderRegistry 获取 API Key', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-      }));
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue('resolved-api-key');
-
-      const config = loadConfig();
-      expect(config.apiKey).toBe('resolved-api-key');
-    });
-
-    it('使用配置文件中的 provider', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'deepseek',
-      }));
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue('deepseek-key');
-
-      const config = loadConfig();
-      expect(config.provider).toBe('deepseek');
-      expect(config.apiKey).toBe('deepseek-key');
-    });
-
-    it('使用默认模型', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue('test-key');
-
-      const config = loadConfig();
-      expect(config.model).toBe('claude-sonnet-4-20250514');
-    });
-
-    it('无 API Key 时退出程序', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue(undefined);
-
-      expect(() => loadConfig()).toThrow('process.exit called');
-      expect(mockConsoleError).toHaveBeenCalled();
-    });
-  });
-
-  describe('loadVisionConfig - 加载 Vision 配置', () => {
-    it('返回 null 当没有 API Key', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadVisionConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue(undefined);
-
-      const config = loadVisionConfig();
-      expect(config).toBeNull();
-    });
-
-    it('从配置文件获取 Vision 设置', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        visionProvider: 'openai',
-        visionModel: 'gpt-4o',
-        visionBaseUrl: 'https://config-vision.example.com',
-      }));
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadVisionConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue('config-vision-key');
-
-      const config = loadVisionConfig();
-      expect(config).not.toBeNull();
-      expect(config!.provider).toBe('openai');
-      expect(config!.model).toBe('gpt-4o');
-      expect(config!.apiKey).toBe('config-vision-key');
-    });
-
-    it('默认使用 anthropic provider', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { resolveApiKey } = await import('../../../src/provider/index.js');
-      const { loadVisionConfig } = await import('../../../src/utils/config.js');
-
-      vi.mocked(resolveApiKey).mockReturnValue('anthropic-key');
-
-      const config = loadVisionConfig();
-      expect(config).not.toBeNull();
-      expect(config!.provider).toBe('anthropic');
-    });
-  });
-
-  describe('saveConfig - 保存配置', () => {
-    it('创建配置目录（如果不存在）', async () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      vi.resetModules();
-      const { saveConfig } = await import('../../../src/utils/config.js');
-
-      saveConfig({ provider: 'anthropic' });
-
-      expect(fs.mkdirSync).toHaveBeenCalledWith(CONFIG_DIR, { recursive: true });
-    });
-
-    it('合并现有配置', async () => {
-      vi.mocked(fs.existsSync).mockImplementation((p) => p === CONFIG_FILE);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-      }));
-
-      vi.resetModules();
-      const { saveConfig } = await import('../../../src/utils/config.js');
-
-      saveConfig({ model: 'claude-opus-4-20250514' });
-
-      expect(fs.writeFileSync).toHaveBeenCalledWith(
-        CONFIG_FILE,
-        expect.stringContaining('"model": "claude-opus-4-20250514"')
-      );
-      expect(fs.writeFileSync).toHaveBeenCalledWith(
-        CONFIG_FILE,
-        expect.stringContaining('"provider": "anthropic"')
-      );
-    });
-
-    it('覆盖相同字段', async () => {
-      vi.mocked(fs.existsSync).mockImplementation((p) => p === CONFIG_FILE);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-        model: 'old-model',
-      }));
-
-      vi.resetModules();
-      const { saveConfig } = await import('../../../src/utils/config.js');
-
-      saveConfig({ model: 'new-model' });
-
-      const writeCall = vi.mocked(fs.writeFileSync).mock.calls[0];
-      const savedConfig = JSON.parse(writeCall[1] as string);
-      expect(savedConfig.model).toBe('new-model');
-    });
-  });
-});
diff --git a/packages/core/tests/unit/utils/config.test.ts b/packages/core/tests/unit/utils/config.test.ts
index 0377985..89c7ea7 100644
--- a/packages/core/tests/unit/utils/config.test.ts
+++ b/packages/core/tests/unit/utils/config.test.ts
@@ -1,108 +1,103 @@
 import { describe, it, expect, beforeEach, vi } from 'vitest';
 
-// Mock fs
-vi.mock('fs', () => ({
-  existsSync: vi.fn(),
-  readFileSync: vi.fn(),
-  writeFileSync: vi.fn(),
-  mkdirSync: vi.fn(),
-}));
-
 // Mock provider registry
 vi.mock('../../../src/provider/index.js', () => ({
   providerRegistry: {
     getInfo: vi.fn(),
     getConfig: vi.fn(),
+    getModelInfo: vi.fn(),
   },
   resolveApiKey: vi.fn(),
 }));
 
-import * as fs from 'fs';
+// Mock agent registry
+vi.mock('../../../src/agent/registry.js', () => ({
+  agentRegistry: {
+    getGlobalConfig: vi.fn(),
+  },
+}));
+
 import { providerRegistry, resolveApiKey } from '../../../src/provider/index.js';
-import { getConfig, loadConfig, saveConfig, loadVisionConfig } from '../../../src/utils/config.js';
+import { agentRegistry } from '../../../src/agent/registry.js';
+import { loadConfig, loadVisionConfig, ConfigurationError } from '../../../src/utils/config.js';
 
 describe('Config - 配置管理', () => {
   beforeEach(() => {
     vi.clearAllMocks();
   });
 
-  describe('getConfig - 获取原始配置', () => {
-    it('配置文件存在时返回内容', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-        model: 'claude-3-opus',
-      }));
-
-      const config = getConfig();
-
-      expect(config.provider).toBe('anthropic');
-      expect(config.model).toBe('claude-3-opus');
-    });
-
-    it('配置文件不存在时返回空对象', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      const config = getConfig();
-
-      expect(config).toEqual({});
-    });
-
-    it('配置文件解析错误时返回空对象', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue('invalid json');
-
-      const config = getConfig();
-
-      expect(config).toEqual({});
-    });
-  });
-
   describe('loadConfig - 加载完整配置', () => {
-    it('通过 ProviderRegistry 获取 Anthropic 配置', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-      vi.mocked(providerRegistry.getConfig).mockReturnValue(undefined);
-      vi.mocked(resolveApiKey).mockReturnValue('resolved-anthropic-key');
+    it('从 AgentRegistry defaults.model 获取配置', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        model: {
+          provider: 'openai',
+          model: 'gpt-4o',
+          maxTokens: 8192,
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({
+        id: 'openai',
+        baseUrl: 'https://api.openai.com/v1',
+      });
+      vi.mocked(resolveApiKey).mockReturnValue('openai-api-key');
 
       const config = loadConfig();
 
-      expect(config.provider).toBe('anthropic');
-      expect(config.apiKey).toBe('resolved-anthropic-key');
-      expect(config.model).toBe('claude-sonnet-4-20250514');
-    });
-
-    it('从配置文件获取 DeepSeek provider', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'deepseek',
-      }));
-      vi.mocked(providerRegistry.getConfig).mockReturnValue(undefined);
-      vi.mocked(resolveApiKey).mockReturnValue('resolved-deepseek-key');
-
-      const config = loadConfig();
-
-      expect(config.provider).toBe('deepseek');
-      expect(config.apiKey).toBe('resolved-deepseek-key');
-      expect(config.model).toBe('deepseek-chat');
-    });
-
-    it('配置文件中的 model 和 maxTokens', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        model: 'custom-model',
-        maxTokens: 8192,
-      }));
-      vi.mocked(providerRegistry.getConfig).mockReturnValue(undefined);
-      vi.mocked(resolveApiKey).mockReturnValue('test-key');
-
-      const config = loadConfig();
-
-      expect(config.model).toBe('custom-model');
+      expect(config.provider).toBe('openai');
+      expect(config.model).toBe('gpt-4o');
+      expect(config.apiKey).toBe('openai-api-key');
       expect(config.maxTokens).toBe(8192);
+      expect(config.baseUrl).toBe('https://api.openai.com/v1');
+    });
+
+    it('未配置 defaults.model 时使用第一个有 API Key 的 provider', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue(null);
+      // anthropic 没有 API Key
+      vi.mocked(providerRegistry.getConfig).mockImplementation((id) => {
+        if (id === 'openai') {
+          return { id: 'openai' };
+        }
+        return undefined;
+      });
+      vi.mocked(resolveApiKey).mockImplementation((config) => {
+        if (config?.id === 'openai') {
+          return 'openai-fallback-key';
+        }
+        return undefined;
+      });
+
+      const config = loadConfig();
+
+      expect(config.provider).toBe('openai');
+      expect(config.apiKey).toBe('openai-fallback-key');
+      expect(config.model).toBe('gpt-4o'); // 默认模型
+    });
+
+    it('没有任何 provider 配置 API Key 时抛出错误', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue(null);
+      vi.mocked(providerRegistry.getConfig).mockReturnValue(undefined);
+      vi.mocked(resolveApiKey).mockReturnValue(undefined);
+
+      expect(() => loadConfig()).toThrow(ConfigurationError);
+      expect(() => loadConfig()).toThrow('请先在 Providers 面板配置一个模型提供商的 API Key');
+    });
+
+    it('配置了 provider 但没有 API Key 时抛出错误', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        model: {
+          provider: 'deepseek',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'deepseek' });
+      vi.mocked(resolveApiKey).mockReturnValue(undefined);
+
+      expect(() => loadConfig()).toThrow(ConfigurationError);
+      expect(() => loadConfig()).toThrow('请在 Providers 面板配置 deepseek 的 API Key');
     });
 
     it('包含系统提示词', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue(null);
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'anthropic' });
       vi.mocked(resolveApiKey).mockReturnValue('test-key');
 
       const config = loadConfig();
@@ -112,7 +107,12 @@ describe('Config - 配置管理', () => {
     });
 
     it('默认 maxTokens 为 4096', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        model: {
+          provider: 'anthropic',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'anthropic' });
       vi.mocked(resolveApiKey).mockReturnValue('test-key');
 
       const config = loadConfig();
@@ -120,11 +120,16 @@ describe('Config - 配置管理', () => {
       expect(config.maxTokens).toBe(4096);
     });
 
-    it('从配置文件获取 baseUrl', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
+    it('从 ProviderConfig 获取 baseUrl', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        model: {
+          provider: 'openai',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({
+        id: 'openai',
         baseUrl: 'https://custom.api.com/v1',
-      }));
+      });
       vi.mocked(resolveApiKey).mockReturnValue('test-key');
 
       const config = loadConfig();
@@ -132,67 +137,44 @@ describe('Config - 配置管理', () => {
       expect(config.baseUrl).toBe('https://custom.api.com/v1');
     });
 
-    it('从 ProviderConfig 获取 baseUrl', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-      vi.mocked(providerRegistry.getConfig).mockReturnValue({
-        id: 'anthropic',
-        baseUrl: 'https://provider-config.api.com/v1',
+    it('获取模型的 contextWindow', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        model: {
+          provider: 'anthropic',
+          model: 'claude-sonnet-4-20250514',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'anthropic' });
+      vi.mocked(providerRegistry.getModelInfo).mockReturnValue({
+        id: 'claude-sonnet-4-20250514',
+        name: 'Claude Sonnet 4',
+        contextWindow: 200000,
       });
       vi.mocked(resolveApiKey).mockReturnValue('test-key');
 
       const config = loadConfig();
 
-      expect(config.baseUrl).toBe('https://provider-config.api.com/v1');
-    });
-  });
-
-  describe('saveConfig - 保存配置', () => {
-    it('创建目录并保存配置', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-
-      saveConfig({ provider: 'anthropic' });
-
-      expect(fs.mkdirSync).toHaveBeenCalledWith(
-        expect.any(String),
-        { recursive: true }
-      );
-      expect(fs.writeFileSync).toHaveBeenCalledWith(
-        expect.any(String),
-        expect.stringContaining('anthropic')
-      );
-    });
-
-    it('合并现有配置', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        provider: 'anthropic',
-        model: 'old-model',
-      }));
-
-      saveConfig({ model: 'new-model' });
-
-      const writeCall = vi.mocked(fs.writeFileSync).mock.calls[0];
-      const savedConfig = JSON.parse(writeCall[1] as string);
-
-      expect(savedConfig.provider).toBe('anthropic');
-      expect(savedConfig.model).toBe('new-model');
-    });
-
-    it('目录已存在时不重新创建', () => {
-      vi.mocked(fs.existsSync)
-        .mockReturnValueOnce(true)  // 目录存在
-        .mockReturnValueOnce(true); // 配置文件存在
-      vi.mocked(fs.readFileSync).mockReturnValue('{}');
-
-      saveConfig({ provider: 'test' });
-
-      expect(fs.mkdirSync).not.toHaveBeenCalled();
+      expect(config.contextWindow).toBe(200000);
     });
   });
 
   describe('loadVisionConfig - Vision 配置', () => {
-    it('返回 null 当没有配置 Vision API Key', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
+    it('返回 null 当没有配置 defaults.vision', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue(null);
+
+      const visionConfig = loadVisionConfig();
+
+      expect(visionConfig).toBeNull();
+    });
+
+    it('返回 null 当 vision provider 没有 API Key', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        vision: {
+          provider: 'openai',
+          model: 'gpt-4o',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'openai' });
       vi.mocked(resolveApiKey).mockReturnValue(undefined);
 
       const visionConfig = loadVisionConfig();
@@ -200,12 +182,17 @@ describe('Config - 配置管理', () => {
       expect(visionConfig).toBeNull();
     });
 
-    it('通过 ProviderRegistry 获取 Vision 配置', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        visionProvider: 'openai',
-        visionModel: 'gpt-4-vision',
-      }));
+    it('从 defaults.vision 获取 Vision 配置', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        vision: {
+          provider: 'openai',
+          model: 'gpt-4o',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({
+        id: 'openai',
+        baseUrl: 'https://api.openai.com/v1',
+      });
       vi.mocked(resolveApiKey).mockReturnValue('vision-api-key');
 
       const visionConfig = loadVisionConfig();
@@ -213,33 +200,17 @@ describe('Config - 配置管理', () => {
       expect(visionConfig).not.toBeNull();
       expect(visionConfig?.provider).toBe('openai');
       expect(visionConfig?.apiKey).toBe('vision-api-key');
-      expect(visionConfig?.model).toBe('gpt-4-vision');
+      expect(visionConfig?.model).toBe('gpt-4o');
+      expect(visionConfig?.baseUrl).toBe('https://api.openai.com/v1');
     });
 
-    it('默认使用 anthropic provider', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
-      vi.mocked(resolveApiKey).mockReturnValue('anthropic-key');
-
-      const visionConfig = loadVisionConfig();
-
-      expect(visionConfig).not.toBeNull();
-      expect(visionConfig?.provider).toBe('anthropic');
-    });
-
-    it('Vision baseUrl 配置', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(true);
-      vi.mocked(fs.readFileSync).mockReturnValue(JSON.stringify({
-        visionBaseUrl: 'https://vision.api.com/v1',
-      }));
-      vi.mocked(resolveApiKey).mockReturnValue('vision-key');
-
-      const visionConfig = loadVisionConfig();
-
-      expect(visionConfig?.baseUrl).toBe('https://vision.api.com/v1');
-    });
-
-    it('使用默认 Vision 模型', () => {
-      vi.mocked(fs.existsSync).mockReturnValue(false);
+    it('使用默认模型当 vision.model 未指定', () => {
+      vi.mocked(agentRegistry.getGlobalConfig).mockReturnValue({
+        vision: {
+          provider: 'anthropic',
+        },
+      });
+      vi.mocked(providerRegistry.getConfig).mockReturnValue({ id: 'anthropic' });
       vi.mocked(resolveApiKey).mockReturnValue('test-key');
 
       const visionConfig = loadVisionConfig();
@@ -247,4 +218,15 @@ describe('Config - 配置管理', () => {
       expect(visionConfig?.model).toBe('claude-sonnet-4-20250514');
     });
   });
+
+  describe('ConfigurationError', () => {
+    it('包含 provider 和 missingKey 信息', () => {
+      const error = new ConfigurationError('Test error', 'openai', 'apiKey');
+
+      expect(error.name).toBe('ConfigurationError');
+      expect(error.message).toBe('Test error');
+      expect(error.provider).toBe('openai');
+      expect(error.missingKey).toBe('apiKey');
+    });
+  });
 });
diff --git a/packages/server/src/agent/adapter.ts b/packages/server/src/agent/adapter.ts
index a872569..91af6ec 100644
--- a/packages/server/src/agent/adapter.ts
+++ b/packages/server/src/agent/adapter.ts
@@ -12,6 +12,7 @@ import { getSessionManager } from '../session/manager.js';
 import { broadcastToSession } from '../ws.js';
 import { emitStatusEvent, emitLogEvent } from '../sse.js';
 import { createServerPermissionCallback, setSessionAutoApprove } from '../permission/handler.js';
+import { getConfig } from '../routes/config.js';
 
 // ============================================================================
 // Core 模块接口定义（避免直接依赖 @ai-assistant/core 类型）
@@ -220,18 +221,22 @@ export async function initCore(): Promise<boolean> {
       return false;
     }
 
+    // 获取服务器配置的工作目录
+    const config = getConfig();
+    const workdir = config.workdir;
+
     // 初始化 ProviderRegistry（加载用户配置）
     const providerRegistry = core.getProviderRegistry();
     if (!providerRegistry.isInitialized()) {
-      await providerRegistry.init();
-      console.log('[Agent] ProviderRegistry initialized');
+      await providerRegistry.init(workdir);
+      console.log('[Agent] ProviderRegistry initialized with workdir:', workdir);
     }
 
     // 初始化 AgentRegistry（加载用户自定义 Agent 配置）
     const agentRegistry = core.agentRegistry;
     if (!agentRegistry.isInitialized()) {
-      await agentRegistry.init(process.cwd());
-      console.log('[Agent] AgentRegistry initialized');
+      await agentRegistry.init(workdir);
+      console.log('[Agent] AgentRegistry initialized with workdir:', workdir);
     }
 
     coreModule = core;
diff --git a/packages/server/src/routes/providers.ts b/packages/server/src/routes/providers.ts
index 05f393b..98cb4dd 100644
--- a/packages/server/src/routes/providers.ts
+++ b/packages/server/src/routes/providers.ts
@@ -5,6 +5,7 @@
  */
 
 import { Hono } from 'hono';
+import { getConfig } from './config.js';
 
 // Types from core - dynamically import to avoid build dependency
 interface ProviderListItem {
@@ -246,7 +247,7 @@ providersRouter.post('/', async (c) => {
 
     const registry = core.getProviderRegistry();
     registry.registerCustom(body);
-    await registry.saveConfig();
+    await registry.saveConfig(getConfig().workdir);
 
     return c.json({
       success: true,
@@ -284,7 +285,7 @@ providersRouter.put('/:id', async (c) => {
     }
 
     registry.setConfig(id, { ...body, id });
-    await registry.saveConfig();
+    await registry.saveConfig(getConfig().workdir);
 
     return c.json({
       success: true,
@@ -320,7 +321,7 @@ providersRouter.delete('/:id', async (c) => {
       return c.json({ success: false, error: `Provider not found: ${id}` }, 404);
     }
 
-    await registry.saveConfig();
+    await registry.saveConfig(getConfig().workdir);
 
     return c.json({
       success: true,
@@ -364,7 +365,7 @@ providersRouter.post('/:id/models', async (c) => {
 
     const registry = core.getProviderRegistry();
     registry.addCustomModel(providerId, body);
-    await registry.saveConfig();
+    await registry.saveConfig(getConfig().workdir);
 
     return c.json({
       success: true,
@@ -407,7 +408,7 @@ providersRouter.delete('/:id/models/:modelId', async (c) => {
       );
     }
 
-    await registry.saveConfig();
+    await registry.saveConfig(getConfig().workdir);
 
     return c.json({
       success: true,
diff --git a/packages/ui/src/api/types.ts b/packages/ui/src/api/types.ts
index 659e587..a0eeb01 100644
--- a/packages/ui/src/api/types.ts
+++ b/packages/ui/src/api/types.ts
@@ -496,6 +496,8 @@ export interface AgentDefaults {
   maxSteps?: number;
   /** 模型配置 */
   model?: AgentModelConfig;
+  /** Vision 模型配置（用于图片理解） */
+  vision?: AgentModelConfig;
   /** 权限配置 */
   permission?: AgentPermission;
 }
diff --git a/packages/ui/src/components/AgentDefaultsEditor.tsx b/packages/ui/src/components/AgentDefaultsEditor.tsx
index b20bd20..ca02cde 100644
--- a/packages/ui/src/components/AgentDefaultsEditor.tsx
+++ b/packages/ui/src/components/AgentDefaultsEditor.tsx
@@ -44,6 +44,10 @@ export function AgentDefaultsEditor({
   const [temperature, setTemperature] = useState<number | undefined>(undefined);
   const [maxTokens, setMaxTokens] = useState<number | undefined>(undefined);
 
+  // Vision 模型配置
+  const [visionProvider, setVisionProvider] = useState<string>('');
+  const [visionModel, setVisionModel] = useState('');
+
   // UI 状态
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
@@ -66,6 +70,11 @@ export function AgentDefaultsEditor({
             setTemperature(defaults.model.temperature);
             setMaxTokens(defaults.model.maxTokens);
           }
+
+          if (defaults.vision) {
+            setVisionProvider(defaults.vision.provider || '');
+            setVisionModel(defaults.vision.model || '');
+          }
         }
       } catch (err) {
         setError(err instanceof Error ? err.message : 'Failed to load defaults');
@@ -103,6 +112,18 @@ export function AgentDefaultsEditor({
       defaults.model = model;
     }
 
+    // Vision 配置
+    const vision: AgentModelConfig = {};
+    if (visionProvider) {
+      vision.provider = visionProvider as 'anthropic' | 'deepseek' | 'openai';
+    }
+    if (visionModel) {
+      vision.model = visionModel;
+    }
+    if (Object.keys(vision).length > 0) {
+      defaults.vision = vision;
+    }
+
     return defaults;
   };
 
@@ -225,6 +246,9 @@ export function AgentDefaultsEditor({
                 {/* Model Configuration */}
                 <div className="space-y-4">
                   <h3 className="text-sm font-medium text-fg-secondary">Default Model</h3>
+                  <p className="text-xs text-fg-subtle -mt-2">
+                    The main model used for all conversations
+                  </p>
                   <div className="grid grid-cols-2 gap-4">
                     {/* Provider */}
                     <div>
@@ -287,6 +311,41 @@ export function AgentDefaultsEditor({
                   </div>
                 </div>
 
+                {/* Vision Model Configuration */}
+                <div className="space-y-4">
+                  <h3 className="text-sm font-medium text-fg-secondary">Vision Model</h3>
+                  <p className="text-xs text-fg-subtle -mt-2">
+                    Used for image understanding when the default model doesn't support vision
+                  </p>
+                  <div className="grid grid-cols-2 gap-4">
+                    {/* Vision Provider */}
+                    <div>
+                      <label className="block text-xs text-fg-muted mb-1">Provider</label>
+                      <select
+                        value={visionProvider}
+                        onChange={(e) => setVisionProvider(e.target.value)}
+                        className="w-full px-3 py-2 bg-surface-base border border-line rounded-lg text-sm focus:outline-none focus:border-primary-500"
+                      >
+                        <option value="">Not configured</option>
+                        <option value="anthropic">Anthropic</option>
+                        <option value="openai">OpenAI</option>
+                      </select>
+                    </div>
+
+                    {/* Vision Model */}
+                    <div>
+                      <label className="block text-xs text-fg-muted mb-1">Model</label>
+                      <input
+                        type="text"
+                        value={visionModel}
+                        onChange={(e) => setVisionModel(e.target.value)}
+                        placeholder="gpt-4o"
+                        className="w-full px-3 py-2 bg-surface-base border border-line rounded-lg text-sm focus:outline-none focus:border-primary-500"
+                      />
+                    </div>
+                  </div>
+                </div>
+
                 {/* Info */}
                 <div className="p-3 bg-blue-500/10 border border-blue-500/30 rounded-lg text-blue-400 text-xs">
                   <p>