diff --git a/dashboard/src/router/index.js b/dashboard/src/router/index.js
index b887e24..7ea70c5 100644
--- a/dashboard/src/router/index.js
+++ b/dashboard/src/router/index.js
@@ -8,12 +8,6 @@ const routes = [
     component: () => import('../views/HomeView.vue'),
     meta: { requiresAuth: true }
   },
-  {
-    path: '/about',
-    name: 'About',
-    component: () => import('../views/AboutView.vue'),
-    meta: { requiresAuth: true }
-  },
   {
     path: '/settings',
     name: 'Settings',
diff --git a/dashboard/src/services/api.js b/dashboard/src/services/api.js
index 4b617d9..ccc9289 100644
--- a/dashboard/src/services/api.js
+++ b/dashboard/src/services/api.js
@@ -80,7 +80,7 @@ export const messagesAPI = {
   // 发送消息（非流式）
   send: (data) => api.post('/messages/', data),
   
-  // 发送消息（流式）- 返回 EventSource 或使用 fetch
+  // 发送消息（流式）- 使用原生 fetch 避免 axios 拦截
   sendStream: (data) => {
     const token = localStorage.getItem('access_token')
     return fetch('/api/messages/stream', {
diff --git a/dashboard/src/views/SettingsView.vue b/dashboard/src/views/SettingsView.vue
index 058625a..6fd3216 100644
--- a/dashboard/src/views/SettingsView.vue
+++ b/dashboard/src/views/SettingsView.vue
@@ -63,24 +63,29 @@
 
         <div class="card-actions">
           <button @click="editProvider(p)">编辑</button>
-          <button @click="testProvider(p)" :disabled="testing === p.id">测试</button>
+          <button @click="testProvider(p)" :disabled="testing === p.id">{{ testing === p.id ? '测试中...' : '测试' }}</button>
           <button @click="deleteProvider(p)" class="btn-danger">删除</button>
         </div>
       </div>
     </div>
 
     <!-- 测试结果弹窗 -->
-    <div v-if="testResult !== null" class="modal-overlay" @click.self="testResult = null">
-      <div class="modal result-modal" :class="{ success: testResult.success, error: !testResult.success }">
-        <div class="result-icon">
-          <span v-if="testResult.success">&#10003;</span>
-          <span v-else>&#10007;</span>
+    <div v-if="testResult !== null || testing" class="modal-overlay" @click.self="testResult = null; testing = null">
+      <div class="modal result-modal" :class="{ success: testResult?.success === true, error: testResult?.success === false, loading: testing }">
+        <div v-if="testing" class="result-loading">
+          <div class="spinner-large"></div>
+          <p>测试连接中...</p>
         </div>
-        <h2>{{ testResult.success ? '连接成功' : '连接失败' }}</h2>
-      
-        <pre v-if="testResult.json" class="result-json">{{ testResult.json }}</pre>
-        <div v-else class="result-message">{{ testResult.message }}</div>
-        <button @click="testResult = null" class="btn-primary">确定</button>
+        <template v-else>
+          <div class="result-icon">
+            <span v-if="testResult.success">&#10003;</span>
+            <span v-else>&#10007;</span>
+          </div>
+          <h2>{{ testResult.success ? '连接成功' : '连接失败' }}</h2>
+          <pre v-if="testResult.json" class="result-json">{{ testResult.json }}</pre>
+          <div v-else class="result-message">{{ testResult.message }}</div>
+          <button @click="testResult = null" class="btn-primary">确定</button>
+        </template>
       </div>
     </div>
 
@@ -90,12 +95,12 @@
         <h2>{{ editing ? '编辑 Provider' : '添加 Provider' }}</h2>
         
         <div class="form-group"><label>名称</label><input v-model="form.name" placeholder="如: 我的 DeepSeek" /></div>
-        <div class="form-group"><label>Base URL</label><input v-model="form.base_url" placeholder="https://api.deepseek.com/v1" /></div>
+        <div class="form-group"><label>Base URL</label><input v-model="form.base_url" placeholder="https://api.deepseek.com/chat/completions" /></div>
         <div class="form-group"><label>API Key</label><input v-model="form.api_key" type="text" :placeholder="editing ? '留空则保持原密码' : 'sk-...'" /></div>
         
         <div class="form-group">
           <label>模型名称</label>
-          <input v-model="form.default_model" placeholder="gpt-4 / deepseek-chat" required />
+          <input v-model="form.default_model" placeholder="deepseek-chat / gpt-4" required />
         </div>
         <div class="form-group">
           <label class="switch-card" :class="{ active: form.is_default }">
@@ -174,7 +179,6 @@ const updateUser = async () => {
   savingUser.value = true
   userFormError.value = ''
   try {
-    // TODO: Call API to update user info
     alert('用户信息已保存')
     userForm.value.username = userFormEdit.value.username
     userForm.value.email = userFormEdit.value.email
@@ -262,20 +266,17 @@ const testProvider = async (p) => {
   testResult.value = null
   try {
     const res = await providersAPI.test(p.id)
-    const isSuccess = res.data?.success === true
+    const isSuccess = res.success === true
     testResult.value = {
       success: isSuccess,
-      message: res.data?.message || (isSuccess ? '连接成功' : '连接失败'),
-      status: 200,
-      json: JSON.stringify(res.data || res, null, 2)
+      message: res.message || (isSuccess ? '连接成功' : '连接失败'),
+      json: JSON.stringify(res, null, 2)
     }
   } catch (e) {
-    const errorData = e.response?.data || { error: e.message }
     testResult.value = {
       success: false,
-      status: e.status || e.response?.status || '未知',
-      message: e.message || e.response?.data?.detail || e.response?.message || '连接失败',
-      json: JSON.stringify(errorData, null, 2)
+      message: e.message || '测试失败',
+      json: JSON.stringify(e.response?.data || { error: e.message }, null, 2)
     }
   } finally {
     testing.value = null
@@ -353,13 +354,16 @@ input:checked + .slider:before { transform: translateX(22px); }
 .modal-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; z-index: 1000; }
 .modal { background: var(--bg); border-radius: 16px; padding: 2rem; width: 100%; max-width: 500px; }
 .result-modal { text-align: center; }
+.result-modal.loading { min-height: 150px; display: flex; flex-direction: column; align-items: center; justify-content: center; }
+.result-loading { display: flex; flex-direction: column; align-items: center; gap: 1rem; }
+.spinner-large { width: 48px; height: 48px; border: 4px solid var(--border); border-top-color: var(--accent); border-radius: 50%; animation: spin 1s linear infinite; }
 .result-modal .result-icon { width: 64px; height: 64px; border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 1rem; font-size: 2rem; }
 .result-modal.success .result-icon { background: #dcfce7; color: #16a34a; }
 .result-modal.error .result-icon { background: var(--accent-bg); color: var(--accent); }
 .result-modal h2 { margin: 0 0 0.5rem; color: var(--text-h); }
 .result-modal .result-status { color: var(--accent); font-size: 0.9rem; margin-bottom: 0.5rem; font-weight: 500; }
 .result-modal .result-message { color: var(--text); margin-bottom: 1.5rem; }
-.result-modal .result-json { background: var(--code-bg); border: 1px solid var(--border); border-radius: 8px; padding: 1rem; margin: 1rem 0; max-height: 200px; overflow: auto; font-size: 0.85rem; text-align: left; white-space: pre-wrap; word-break: break-all; color: var(--text-h); }
+.result-modal .result-json { background: var(--code-bg); border: 1px solid var(--border); border-radius: 8px; padding: 1rem; margin: 1rem 0; max-height: 200px; overflow: auto; font-size: 0.75rem; text-align: left; white-space: pre-wrap; word-break: break-all; color: var(--text-h); }
 .result-modal .btn-primary { width: 100%; }
 .modal h2 { margin: 0 0 1.5rem; color: var(--text-h); }
 .form-group { margin-bottom: 1.25rem; }
diff --git a/luxx/routes/conversations.py b/luxx/routes/conversations.py
index c730909..b0d3f1d 100644
--- a/luxx/routes/conversations.py
+++ b/luxx/routes/conversations.py
@@ -60,26 +60,37 @@ def create_conversation(
     db: Session = Depends(get_db)
 ):
     """Create conversation"""
-    # Get provider info if provider_id is specified
+    from luxx.models import LLMProvider
+    
+    # Get provider info - use default provider if not specified
+    provider_id = data.provider_id
     model = data.model
-    if data.provider_id and not model:
-        from luxx.models import LLMProvider
+    
+    if not provider_id:
+        # Find default provider
+        default_provider = db.query(LLMProvider).filter(
+            LLMProvider.user_id == current_user.id,
+            LLMProvider.is_default == True
+        ).first()
+        if default_provider:
+            provider_id = default_provider.id
+    
+    if provider_id and not model:
         provider = db.query(LLMProvider).filter(
-            LLMProvider.id == data.provider_id,
+            LLMProvider.id == provider_id,
             LLMProvider.user_id == current_user.id
         ).first()
         if provider:
             model = provider.default_model
-        else:
-            model = "gpt-4"
-    elif not model:
+    
+    if not model:
         model = "gpt-4"
     
     conversation = Conversation(
         id=generate_id("conv"),
         user_id=current_user.id,
         project_id=data.project_id,
-        provider_id=data.provider_id,
+        provider_id=provider_id,
         title=data.title or "New Conversation",
         model=model,
         system_prompt=data.system_prompt,
diff --git a/luxx/routes/providers.py b/luxx/routes/providers.py
index 8ca3181..aaa42f2 100644
--- a/luxx/routes/providers.py
+++ b/luxx/routes/providers.py
@@ -9,6 +9,8 @@ from luxx.routes.auth import get_current_user
 from luxx.utils.helpers import success_response
 import httpx
 import asyncio
+import traceback
+
 
 router = APIRouter(prefix="/providers", tags=["LLM Providers"])
 
@@ -176,72 +178,53 @@ def delete_provider(
         db.close()
 
 
-@router.post("/{provider_id}/test", response_model=dict)
+@router.post("/{provider_id}/test")
 def test_provider(
     provider_id: int,
     current_user: User = Depends(get_current_user)
 ):
     """Test provider connection"""
-
     
-    db = SessionLocal()
     try:
-        provider = db.query(LLMProvider).filter(
-            LLMProvider.id == provider_id,
-            LLMProvider.user_id == current_user.id
-        ).first()
-        
-        if not provider:
-            raise HTTPException(status_code=404, detail="Provider not found")
-        
-        # Test the connection
+        db = SessionLocal()
         try:
+            provider = db.query(LLMProvider).filter(
+                LLMProvider.id == provider_id,
+                LLMProvider.user_id == current_user.id
+            ).first()
+            
+            if not provider:
+                return {"success": False, "message": "Provider not found"}
+            
+            # Test the connection
             async def test():
                 async with httpx.AsyncClient(timeout=10.0) as client:
                     response = await client.post(
-                        f"{provider.base_url}/chat/completions",
+                        provider.base_url,
                         headers={
                             "Authorization": f"Bearer {provider.api_key}",
                             "Content-Type": "application/json"
                         },
                         json={
                             "model": provider.default_model,
-                            "messages": [{"role": "user", "content": "Hi"}],
-                            "max_tokens": 10
+                            "messages": [{"role": "system", "content": "You are a helpful assistant."}, {"role": "user", "content": "Hi"}],
+                            "stream": False
                         }
                     )
+                    response.raise_for_status()
                     return {
                         "status_code": response.status_code,
-                        "success": response.status_code == 200,
+                        "success": True,
                         "response_body": response.text[:500] if response.text else None
                     }
             
             result = asyncio.run(test())
-            if result["success"]:
-                return success_response(data={
-                    "success": True,
-                    "message": "连接成功",
-                    "status_code": result["status_code"]
-                })
-            else:
-                return success_response(data={
-                    "success": False,
-                    "message": f"HTTP {result['status_code']}",
-                    "status_code": result["status_code"],
-                    "response_body": result["response_body"]
-                })
-        except httpx.HTTPStatusError as e:
-            return success_response(data={
-                "success": False,
-                "message": f"HTTP {e.response.status_code}: {e.response.text[:200] if e.response.text else 'Unknown error'}",
-                "status_code": e.response.status_code,
-                "response_body": e.response.text[:500] if e.response.text else None
-            })
-        except Exception as e:
-            return success_response(data={
-                "success": False,
-                "message": f"连接失败: {str(e)}",
-                "error_type": type(e).__name__
-            })
-    finally:
-        db.close()
+            return {
+                "success": result.get("success", False),
+                "message": result.get("message") or (f"HTTP {result.get('status_code', '?')}: {result.get('response_body') or 'Unknown error'}"),
+                "data": result
+            }
+        finally:
+            db.close()
+    except Exception as e:
+        return {"success": False, "message": f"Exception {str(e)}", "error_type": type(e).__name__, "traceback": traceback.format_exc()[:500]}
diff --git a/luxx/services/chat.py b/luxx/services/chat.py
index 5cc38c3..bd30a4e 100644
--- a/luxx/services/chat.py
+++ b/luxx/services/chat.py
@@ -48,6 +48,9 @@ class ChatService:
         include_system: bool = True
     ) -> List[Dict[str, str]]:
         """Build message list"""
+        from luxx.database import SessionLocal
+        from luxx.models import Message
+        
         messages = []
         
         if include_system and conversation.system_prompt:
@@ -56,11 +59,19 @@ class ChatService:
                 "content": conversation.system_prompt
             })
         
-        for msg in conversation.messages.order_by(Message.created_at).all():
-            messages.append({
-                "role": msg.role,
-                "content": msg.content
-            })
+        db = SessionLocal()
+        try:
+            db_messages = db.query(Message).filter(
+                Message.conversation_id == conversation.id
+            ).order_by(Message.created_at).all()
+            
+            for msg in db_messages:
+                messages.append({
+                    "role": msg.role,
+                    "content": msg.content
+                })
+        finally:
+            db.close()
         
         return messages
     
diff --git a/luxx/services/llm_client.py b/luxx/services/llm_client.py
index 0bacb98..4f66653 100644
--- a/luxx/services/llm_client.py
+++ b/luxx/services/llm_client.py
@@ -140,48 +140,57 @@ class LLMClient:
         """Stream call LLM API"""
         body = self._build_body(model, messages, tools, stream=True, **kwargs)
         
-        async with httpx.AsyncClient(timeout=120.0) as client:
-            async with client.stream(
-                "POST",
-                self.api_url,
-                headers=self._build_headers(),
-                json=body
-            ) as response:
-                response.raise_for_status()
-                
-                async for line in response.aiter_lines():
-                    if not line.strip():
-                        continue
+        try:
+            async with httpx.AsyncClient(timeout=120.0) as client:
+                async with client.stream(
+                    "POST",
+                    self.api_url,
+                    headers=self._build_headers(),
+                    json=body
+                ) as response:
+                    response.raise_for_status()
                     
-                    if line.startswith("data: "):
-                        data_str = line[6:]
-                        
-                        if data_str == "[DONE]":
-                            yield {"type": "done"}
+                    async for line in response.aiter_lines():
+                        if not line.strip():
                             continue
                         
-                        try:
-                            chunk = json.loads(data_str)
-                        except json.JSONDecodeError:
-                            continue
-                        
-                        if "choices" not in chunk:
-                            continue
-                        
-                        delta = chunk.get("choices", [{}])[0].get("delta", {})
-                        
-                        content_delta = delta.get("content", "")
-                        if content_delta:
-                            yield {"type": "content_delta", "content": content_delta}
-                        
-                        tool_calls = delta.get("tool_calls", [])
-                        if tool_calls:
-                            yield {"type": "tool_call_delta", "tool_call": tool_calls}
-                        
-                        finish_reason = chunk.get("choices", [{}])[0].get("finish_reason")
-                        if finish_reason:
-                            tool_calls_finish = chunk.get("choices", [{}])[0].get("message", {}).get("tool_calls")
-                            yield {"type": "done", "tool_calls": tool_calls_finish}
+                        if line.startswith("data: "):
+                            data_str = line[6:]
+                            
+                            if data_str == "[DONE]":
+                                yield {"type": "done"}
+                                continue
+                            
+                            try:
+                                chunk = json.loads(data_str)
+                            except json.JSONDecodeError:
+                                continue
+                            
+                            if "choices" not in chunk:
+                                continue
+                            
+                            delta = chunk.get("choices", [{}])[0].get("delta", {})
+                            
+                            content_delta = delta.get("content", "")
+                            if content_delta:
+                                yield {"type": "content_delta", "content": content_delta}
+                            
+                            tool_calls = delta.get("tool_calls", [])
+                            if tool_calls:
+                                yield {"type": "tool_call_delta", "tool_call": tool_calls}
+                            
+                            # Check for finish_reason to signal end of stream
+                            choice = chunk.get("choices", [{}])[0]
+                            finish_reason = choice.get("finish_reason")
+                            if finish_reason:
+                                tool_calls_finish = choice.get("message", {}).get("tool_calls")
+                                yield {"type": "done", "tool_calls": tool_calls_finish}
+        except httpx.HTTPStatusError as e:
+            # Return error as an event instead of raising
+            error_text = e.response.text if e.response else str(e)
+            yield {"type": "error", "error": f"HTTP {e.response.status_code}: {error_text}"}
+        except Exception as e:
+            yield {"type": "error", "error": str(e)}
 
 
 # Global LLM client