diff --git a/docker-compose.yml b/docker-compose.yml
index 4c5ef6da85132867d93d174fd015fd2437a85e67..fd952ac4fcbf5e6583661860b7dcb53b255eb352 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -38,6 +38,7 @@ services:
       SPRING_AI_OLLAMA_BASE_URL: http://ollama:11434
       SPRING_AI_OLLAMA_CHAT_MODEL:  gpt-oss:20b
       SPRING_AI_OLLAMA_CHAT_TEMPERATURE: 0.7
+      SPRING_AI_CHAT_SYSTEM_PROMPT: "You are an OpenSlice AI assistant"
       
       # MCP Client Configuration
       SPRING_AI_MCP_CLIENT_TYPE: SYNC
diff --git a/src/main/java/org/etsi/osl/mcp/backend/ChatController.java b/src/main/java/org/etsi/osl/mcp/backend/ChatController.java
index 2d9fbcca118d11ba3c94395e9d5619953fcc9176..ff0bc740cb2241fe690db977ab9882fda636bba6 100644
--- a/src/main/java/org/etsi/osl/mcp/backend/ChatController.java
+++ b/src/main/java/org/etsi/osl/mcp/backend/ChatController.java
@@ -1,27 +1,39 @@
 package org.etsi.osl.mcp.backend;
 
 import java.util.Map;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.ai.chat.client.ChatClient;
 import org.springframework.ai.chat.client.advisor.SimpleLoggerAdvisor;
 import org.springframework.ai.tool.ToolCallbackProvider;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.annotation.Lazy;
-import org.springframework.web.bind.annotation.*;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 public class ChatController {
     private static final Logger log = LoggerFactory.getLogger(ChatController.class);
     private final ChatClient chatClient;
+    private final String systemPrompt;
     
 
     public ChatController(ChatClient.Builder chatClientBuilder,
-                           ToolCallbackProvider tools) {
+                           ToolCallbackProvider tools,
+                           @Value("${spring.ai.chat.system-prompt}") String systemPrompt) {
+        // Validate that system prompt is not empty
+        if (systemPrompt == null || systemPrompt.trim().isEmpty()) {
+            throw new IllegalArgumentException("System prompt cannot be null or empty. Please configure SPRING_AI_CHAT_SYSTEM_PROMPT with a valid value.");
+        }
+        
+        this.systemPrompt = systemPrompt;
         this.chatClient = chatClientBuilder
                 .defaultAdvisors(new SimpleLoggerAdvisor())
                 .defaultToolCallbacks(tools)
+                .defaultSystem(systemPrompt)
                 .build();
+        log.info("ChatController initialized with system prompt: {}", systemPrompt);
     }
 
     @PostMapping("/ask")
diff --git a/src/main/resources/application.yaml b/src/main/resources/application.yaml
index 83819de6ff53a1adecd2858ac086e459b8d3250a..a485f68d912af1e7c12e3cd964cd91805d032c60 100644
--- a/src/main/resources/application.yaml
+++ b/src/main/resources/application.yaml
@@ -12,6 +12,8 @@ spring:
         options:
           model: ${SPRING_AI_OLLAMA_CHAT_MODEL:gpt-oss:20b}
           temperature: ${SPRING_AI_OLLAMA_CHAT_TEMPERATURE:0.7}
+    chat:
+      system-prompt: ${SPRING_AI_CHAT_SYSTEM_PROMPT:You are an OpenSlice AI assistant.}
     mcp:
       client:
         type: ${SPRING_AI_MCP_CLIENT_TYPE:SYNC}  # or ASYNC