feat: integrated with sandbox

backend/src/agents/__init__.py

@@ -1,3 +1,4 @@
 from .lead_agent import lead_agent
+from .thread_state import SandboxState, ThreadState
 
-__all__ = ["lead_agent"]
+__all__ = ["lead_agent", "SandboxState", "ThreadState"]

backend/src/agents/lead_agent/agent.py

@@ -1,11 +1,15 @@
 from langchain.agents import create_agent
 
 from src.agents.lead_agent.prompt import apply_prompt_template
+from src.agents.thread_state import ThreadState
 from src.models import create_chat_model
+from src.sandbox.middleware import SandboxMiddleware
 from src.tools import get_available_tools
 
 lead_agent = create_agent(
     model=create_chat_model(thinking_enabled=True),
     tools=get_available_tools(),
+    middleware=[SandboxMiddleware()],
     system_prompt=apply_prompt_template(),
+    state_schema=ThreadState,
 )

backend/src/agents/thread_state.py

@@ -0,0 +1,11 @@
+from typing import TypedDict
+
+from langchain.agents import AgentState
+
+
+class SandboxState(TypedDict):
+    sandbox_id: str | None = None
+
+
+class ThreadState(AgentState):
+    sandbox: SandboxState | None = None