examples(foundational): use system_instruction in all examples

examples/foundational/15a-switch-languages.py

@@ -103,7 +103,10 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
 
     tts = SwitchLanguage()
 
-    llm = OpenAILLMService(api_key=os.getenv("OPENAI_API_KEY"))
+    llm = OpenAILLMService(
+        api_key=os.getenv("OPENAI_API_KEY"),
+        system_instruction="You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities. Respond to what the user said in a creative and helpful way. Your output should not include non-alphanumeric characters. You can speak the following languages: 'English' and 'Spanish'.",
+    )
     llm.register_function("switch_language", tts.switch_language)
 
     switch_language_function = FunctionSchema(
@@ -118,14 +121,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
         required=["language"],
     )
     tools = ToolsSchema(standard_tools=[switch_language_function])
-    messages = [
-        {
-            "role": "system",
-            "content": "You are a helpful LLM in a WebRTC call. Your goal is to demonstrate your capabilities. Respond to what the user said in a creative and helpful way. Your output should not include non-alphanumeric characters. You can speak the following languages: 'English' and 'Spanish'.",
-        },
-    ]
-
-    context = LLMContext(messages, tools)
+    context = LLMContext(tools=tools)
     user_aggregator, assistant_aggregator = LLMContextAggregatorPair(
         context,
         user_params=LLMUserAggregatorParams(vad_analyzer=SileroVADAnalyzer()),
@@ -156,7 +152,7 @@ async def run_bot(transport: BaseTransport, runner_args: RunnerArguments):
     async def on_client_connected(transport, client):
         logger.info(f"Client connected")
         # Kick off the conversation.
-        messages.append(
+        context.add_message(
             {
                 "role": "system",
                 "content": f"Please introduce yourself to the user and let them know the languages you speak. Your initial responses should be in {tts.current_language}.",