diff --git a/backend/app/main.py b/backend/app/main.py
index 160df65..1f1f30a 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -278,7 +278,7 @@ def extract_pdf_text_smart(pdf_content: bytes, max_chars: int = None) -> dict:
         }
 
 
-BACKEND_VERSION = "1.2.12"
+BACKEND_VERSION = "1.2.13"
 app = FastAPI(title="Checklist Inteligente API", version=BACKEND_VERSION)
 
 # S3/MinIO configuration
@@ -3453,6 +3453,11 @@ async def chat_with_ai_assistant(
     print(f"📝 Context answers: {len(context_answers_list)} respuestas previas")
     print(f"💭 Chat history: {len(chat_history_list)} mensajes previos")
     
+    # Detectar si es el mensaje inicial de bienvenida
+    is_initial_greeting = (user_message == "__INITIAL_GREETING__")
+    if is_initial_greeting:
+        print("🎉 MENSAJE INICIAL DE BIENVENIDA")
+    
     # Procesar archivos adjuntos
     attached_files_data = []
     if files:
@@ -3564,6 +3569,36 @@ INFORMACIÓN DEL VEHÍCULO:
                 if observations:
                     answers_context += f"   Observaciones: {observations}\n"
         
+        # Si es mensaje inicial, generar saludo contextualizado
+        if is_initial_greeting:
+            greeting_parts = ["¡Hola! Soy tu Asistente Ayutec."]
+            
+            # Mencionar instrucciones específicas si existen
+            if assistant_instructions:
+                greeting_parts.append(f"\n\n{assistant_instructions}")
+            elif assistant_prompt:
+                greeting_parts.append(f"\n\nEstoy aquí para ayudarte con: {assistant_prompt}")
+            
+            # Mencionar contexto disponible
+            context_info = []
+            if context_answers_list:
+                context_info.append(f"{len(context_answers_list)} respuestas anteriores")
+            if context_photos_list:
+                context_info.append(f"{len(context_photos_list)} fotografías")
+            
+            if context_info:
+                greeting_parts.append(f"\n\nHe analizado {' y '.join(context_info)} de esta inspección del vehículo {vehicle_info_dict.get('brand', '')} {vehicle_info_dict.get('model', '')} (Placa: {vehicle_info_dict.get('plate', '')}).")
+            
+            # Pregunta específica o solicitud de información
+            if assistant_prompt:
+                greeting_parts.append("\n\n¿Qué información necesitas o deseas que analice?")
+            else:
+                greeting_parts.append("\n\n¿En qué puedo ayudarte con esta inspección?")
+            
+            # Reemplazar el mensaje especial con el saludo generado
+            user_message = "".join(greeting_parts)
+            print(f"✅ Mensaje de bienvenida generado: {user_message[:100]}...")
+        
         # Definir la longitud de respuesta
         max_tokens_map = {
             'short': 200,
diff --git a/frontend/package.json b/frontend/package.json
index 907c90e..a307bd6 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
 {
   "name": "checklist-frontend",
   "private": true,
-  "version": "1.3.8",
+  "version": "1.3.9",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/frontend/public/service-worker.js b/frontend/public/service-worker.js
index 464b954..a470c2e 100644
--- a/frontend/public/service-worker.js
+++ b/frontend/public/service-worker.js
@@ -1,6 +1,6 @@
 // Service Worker para PWA con detección de actualizaciones
 // IMPORTANTE: Actualizar esta versión cada vez que se despliegue una nueva versión
-const CACHE_NAME = 'ayutec-v1.3.8';
+const CACHE_NAME = 'ayutec-v1.3.9';
 const urlsToCache = [
   '/',
   '/index.html'
diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 7ae0bb0..e6fc0f7 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -4384,6 +4384,7 @@ function InspectionModal({ checklist, existingInspection, user, onClose, onCompl
   const [showAIChat, setShowAIChat] = useState(false)
   const [aiChatMessages, setAiChatMessages] = useState([])
   const [aiChatLoading, setAiChatLoading] = useState(false)
+  const [initialMessageSent, setInitialMessageSent] = useState(false)
   
   // Signature canvas
   const mechanicSigRef = useRef(null)
@@ -5309,9 +5310,10 @@ function InspectionModal({ checklist, existingInspection, user, onClose, onCompl
                     <button
                       type="button"
                       onClick={() => {
+                        const existingHistory = answers[currentQuestion.id]?.chatHistory || []
+                        setAiChatMessages(existingHistory)
+                        setInitialMessageSent(existingHistory.length > 0) // Solo enviar inicial si no hay historial
                         setShowAIChat(true)
-                        // SIEMPRE inicializar - cargar historial guardado O array vacío para nueva sesión
-                        setAiChatMessages(answers[currentQuestion.id]?.chatHistory || [])
                       }}
                       className="w-full mt-3 px-4 py-3 bg-gradient-to-r from-purple-600 to-blue-600 text-white rounded-lg hover:from-purple-700 hover:to-blue-700 transition flex items-center justify-center gap-2 font-semibold shadow-lg"
                     >
@@ -5647,12 +5649,14 @@ function InspectionModal({ checklist, existingInspection, user, onClose, onCompl
       {showAIChat && currentQuestion && (
         <AIAssistantChatModal
           question={currentQuestion}
-          inspection={{ id: inspectionId, ...vehicleData }}
+          inspection={{ id: inspectionId, ...vehicleData, checklist: checklist }}
           allAnswers={answers}
           messages={aiChatMessages}
           setMessages={setAiChatMessages}
           loading={aiChatLoading}
           setLoading={setAiChatLoading}
+          initialMessageSent={initialMessageSent}
+          setInitialMessageSent={setInitialMessageSent}
           onClose={() => {
             setShowAIChat(false)
             // Guardar historial del chat en la respuesta
@@ -5673,7 +5677,7 @@ function InspectionModal({ checklist, existingInspection, user, onClose, onCompl
 }
 
 // Componente Modal de Chat IA Asistente
-function AIAssistantChatModal({ question, inspection, allAnswers, messages, setMessages, loading, setLoading, onClose }) {
+function AIAssistantChatModal({ question, inspection, allAnswers, messages, setMessages, loading, setLoading, initialMessageSent, setInitialMessageSent, onClose }) {
   const [inputMessage, setInputMessage] = useState('')
   const [attachedFiles, setAttachedFiles] = useState([])
   const [selectedImage, setSelectedImage] = useState(null) // Para lightbox
@@ -5686,6 +5690,14 @@ function AIAssistantChatModal({ question, inspection, allAnswers, messages, setM
     chatEndRef.current?.scrollIntoView({ behavior: 'smooth' })
   }, [messages])
 
+  // Generar mensaje de bienvenida automático al abrir el chat
+  useEffect(() => {
+    if (!initialMessageSent && messages.length === 0) {
+      sendInitialMessage()
+      setInitialMessageSent(true)
+    }
+  }, [initialMessageSent])
+
   // Limpiar URLs temporales al desmontar el componente
   useEffect(() => {
     return () => {
@@ -5697,6 +5709,122 @@ function AIAssistantChatModal({ question, inspection, allAnswers, messages, setM
     }
   }, [attachedFiles])
 
+  // Enviar mensaje inicial de bienvenida del asistente
+  const sendInitialMessage = async () => {
+    setLoading(true)
+
+    try {
+      const token = localStorage.getItem('token')
+      const API_URL = import.meta.env.VITE_API_URL || ''
+
+      // Preparar contexto para el mensaje inicial
+      const contextPhotos = []
+      const contextAnswers = []
+      const config = question.options || {}
+      
+      const contextQuestionIds = config.context_questions 
+        ? config.context_questions.split(',').map(id => parseInt(id.trim()))
+        : Object.keys(allAnswers).map(id => parseInt(id))
+
+      const previousQuestionIds = contextQuestionIds.filter(id => id < question.id)
+
+      previousQuestionIds.forEach(qId => {
+        const answer = allAnswers[qId]
+        
+        if (answer?.photos && answer.photos.length > 0) {
+          answer.photos.forEach(photoUrl => {
+            contextPhotos.push({
+              questionId: qId,
+              url: photoUrl,
+              aiAnalysis: answer.aiAnalysis
+            })
+          })
+        }
+        
+        if (answer?.value || answer?.observations) {
+          const questionData = inspection?.checklist?.questions?.find(q => q.id === qId)
+          
+          let formattedAnswer = answer.value || ''
+          if (questionData?.options?.type) {
+            const qType = questionData.options.type
+            
+            if (qType === 'boolean') {
+              formattedAnswer = answer.value === 'true' ? 'Sí' : answer.value === 'false' ? 'No' : formattedAnswer
+            } else if (qType === 'single_choice' && questionData.options.choices) {
+              const selectedChoice = questionData.options.choices.find(c => c.value === answer.value)
+              formattedAnswer = selectedChoice?.label || answer.value
+            } else if (qType === 'scale') {
+              formattedAnswer = `${answer.value} (escala ${questionData.options.min || 1}-${questionData.options.max || 10})`
+            }
+          }
+          
+          contextAnswers.push({
+            questionId: qId,
+            questionText: questionData?.text || `Pregunta ${qId}`,
+            questionType: questionData?.options?.type || 'text',
+            answer: formattedAnswer,
+            observations: answer.observations || ''
+          })
+        }
+      })
+
+      const formData = new FormData()
+      formData.append('question_id', question.id)
+      formData.append('inspection_id', inspection.id)
+      formData.append('user_message', '__INITIAL_GREETING__') // Mensaje especial para identificar inicio
+      formData.append('chat_history', JSON.stringify([]))
+      formData.append('assistant_prompt', config.assistant_prompt || '')
+      formData.append('assistant_instructions', config.assistant_instructions || '')
+      formData.append('response_length', config.response_length || 'medium')
+      formData.append('context_photos', JSON.stringify(contextPhotos))
+      formData.append('context_answers', JSON.stringify(contextAnswers))
+      formData.append('vehicle_info', JSON.stringify({
+        brand: inspection.vehicle_brand,
+        model: inspection.vehicle_model,
+        plate: inspection.vehicle_plate,
+        km: inspection.vehicle_km
+      }))
+
+      console.log('📤 Generando mensaje de bienvenida del asistente...')
+
+      const response = await fetch(`${API_URL}/api/ai/chat-assistant`, {
+        method: 'POST',
+        headers: {
+          'Authorization': `Bearer ${token}`
+        },
+        body: formData
+      })
+
+      if (!response.ok) {
+        throw new Error('Error en respuesta del servidor')
+      }
+
+      const data = await response.json()
+
+      // Crear solo el mensaje del asistente (sin mensaje del usuario)
+      const assistantMessage = {
+        role: 'assistant',
+        content: data.response,
+        timestamp: new Date().toISOString(),
+        confidence: data.confidence
+      }
+
+      setMessages([assistantMessage])
+
+    } catch (error) {
+      console.error('Error al generar mensaje inicial:', error)
+      const errorMessage = {
+        role: 'assistant',
+        content: '❌ Error al inicializar el chat. Por favor intenta nuevamente.',
+        timestamp: new Date().toISOString(),
+        isError: true
+      }
+      setMessages([errorMessage])
+    } finally {
+      setLoading(false)
+    }
+  }
+
   // Manejar adjuntos de archivos
   const handleFileAttach = (e) => {
     const files = Array.from(e.target.files)
diff --git a/frontend/src/Sidebar.jsx b/frontend/src/Sidebar.jsx
index 1f19e9f..7e38e3f 100644
--- a/frontend/src/Sidebar.jsx
+++ b/frontend/src/Sidebar.jsx
@@ -153,7 +153,7 @@ export default function Sidebar({ user, activeTab, setActiveTab, sidebarOpen, se
                 className="w-10 h-10 object-contain bg-white rounded p-1"
               />
               <p className="text-xs text-indigo-300 font-medium hover:text-indigo-200">
-                Ayutec v1.3.8
+                Ayutec v1.3.9
               </p>
             </a>
           </div>