feat: add a subagent frame

agentlite/examples/single_agent.py

@@ -0,0 +1,42 @@
+"""Example: Single Agent Usage
+
+This example demonstrates basic usage of the AgentLite Agent class.
+"""
+
+import asyncio
+import os
+
+from agentlite import Agent, OpenAIProvider
+
+
+async def main():
+    """Run the single agent example."""
+    # Create provider
+    provider = OpenAIProvider(
+        api_key=os.getenv("OPENAI_API_KEY", "your-api-key"),
+        model="gpt-4o-mini",
+    )
+
+    # Create agent
+    agent = Agent(
+        provider=provider,
+        system_prompt="You are a helpful assistant. Be concise.",
+    )
+
+    # Run conversation
+    print("User: What is Python?")
+    response = await agent.run("What is Python?")
+    print(f"Agent: {response}\n")
+
+    print("User: What are its main features?")
+    response = await agent.run("What are its main features?")
+    print(f"Agent: {response}\n")
+
+    # Show conversation history
+    print("--- Conversation History ---")
+    for msg in agent.history:
+        print(f"{msg.role}: {msg.extract_text()[:100]}...")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())