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

backend/src/config/app_config.py

@@ -26,7 +26,7 @@ class AppConfig(BaseModel):
         Priority:
         1. If provided `config_path` argument, use it.
         2. If provided `DEER_FLOW_CONFIG_PATH` environment variable, use it.
-        3. Otherwise, first check the `config.yaml` in the current directory, then use `config.yaml` in the parent directory.
+        3. Otherwise, first check the `config.yaml` in the current directory, then fallback to `config.yaml` in the parent directory.
         """
         if config_path:
             path = Path(config_path)
@@ -39,10 +39,13 @@ class AppConfig(BaseModel):
                 raise FileNotFoundError(f"Config file specified by environment variable `DEER_FLOW_CONFIG_PATH` not found at {path}")
             return path
         else:
-            # Check if the config.yaml is in the parent directory of CWD
+            # Check if the config.yaml is in the current directory
-            path = Path(os.getcwd()).parent / "config.yaml"
+            path = Path(os.getcwd()) / "config.yaml"
             if not path.exists():
-                raise FileNotFoundError(f"Config file not found at {path}")
+                # Check if the config.yaml is in the parent directory of CWD
+                path = Path(os.getcwd()).parent / "config.yaml"
+                if not path.exists():
+                    raise FileNotFoundError("`config.yaml` file not found at the current directory nor its parent directory")
             return path
 
     @classmethod

backend/src/sandbox/local/local_sandbox_provider.py

@@ -13,9 +13,11 @@ class LocalSandboxProvider(SandboxProvider):
         return _singleton.id
 
     def get(self, sandbox_id: str) -> None:
-        if _singleton is None:
+        if sandbox_id == "local":
-            self.acquire()
+            if _singleton is None:
-        return _singleton
+                self.acquire()
+            return _singleton
+        return None
 
     def release(self, sandbox_id: str) -> None:
         pass

backend/src/sandbox/middleware.py

@@ -0,0 +1,33 @@
+from typing import override
+
+from langchain.agents import AgentState
+from langchain.agents.middleware import AgentMiddleware
+from langgraph.runtime import Runtime
+
+from src.agents.thread_state import SandboxState
+from src.sandbox import get_sandbox_provider
+
+
+class SandboxMiddlewareState(AgentState):
+    """Compatible with the `ThreadState` schema."""
+
+    sandbox: SandboxState | None = None
+
+
+class SandboxMiddleware(AgentMiddleware[SandboxMiddlewareState]):
+    """Create a sandbox environment and assign it to an agent."""
+
+    state_schema = SandboxMiddlewareState
+
+    def _acquire_sandbox(self) -> str:
+        provider = get_sandbox_provider()
+        sandbox_id = provider.acquire()
+        print(f"Acquiring sandbox {sandbox_id}")
+        return sandbox_id
+
+    @override
+    def before_agent(self, state: SandboxMiddlewareState, runtime: Runtime) -> dict | None:
+        if "sandbox" not in state or state["sandbox"] is None:
+            sandbox_id = self._acquire_sandbox()
+            return {"sandbox": {"sandbox_id": sandbox_id}}
+        return super().before_agent(state, runtime)

backend/src/sandbox/sandbox_provider.py

@@ -10,7 +10,7 @@ class SandboxProvider(ABC):
 
     @abstractmethod
     def acquire(self) -> str:
-        """Acquire a sandbox environment.
+        """Acquire a sandbox environment and return its ID.
 
         Returns:
             The ID of the acquired sandbox environment.
@@ -18,7 +18,7 @@ class SandboxProvider(ABC):
         pass
 
     @abstractmethod
-    def get(self, sandbox_id: str) -> Sandbox:
+    def get(self, sandbox_id: str) -> Sandbox | None:
         """Get a sandbox environment by ID.
 
         Args:

backend/src/sandbox/tools.py

@@ -1,10 +1,28 @@
-from langchain.tools import tool
+from langchain.tools import ToolRuntime, tool
+from langgraph.typing import ContextT
 
+from src.agents.thread_state import ThreadState
+from src.sandbox.sandbox import Sandbox
 from src.sandbox.sandbox_provider import get_sandbox_provider
 
 
+def sandbox_from_runtime(runtime: ToolRuntime[ContextT, ThreadState] | None = None) -> Sandbox:
+    if runtime is None:
+        raise ValueError("No sandbox found: No runtime found")
+    sandbox_state = runtime.state.get("sandbox")
+    if sandbox_state is None:
+        raise ValueError("No sandbox found: No sandbox state found in runtime")
+    sandbox_id = sandbox_state.get("sandbox_id")
+    if sandbox_id is None:
+        raise ValueError("No sandbox ID found: No sandbox ID found in sandbox state")
+    sandbox = get_sandbox_provider().get(sandbox_id)
+    if sandbox is None:
+        raise ValueError(f"No sandbox found: sandbox with ID {sandbox_id} not found")
+    return sandbox
+
+
 @tool("bash", parse_docstring=True)
-def bash_tool(description: str, command: str) -> str:
+def bash_tool(runtime: ToolRuntime[ContextT, ThreadState], description: str, command: str) -> str:
     """Execute a bash command in a Linux environment.
 
 
@@ -12,29 +30,26 @@ def bash_tool(description: str, command: str) -> str:
     - Use `pip install` to install Python packages.
 
     Args:
-        description: Explain why you are running this command in short words.
+        description: Explain why you are running this command in short words. ALWAYS PROVIDE THIS PARAMETER FIRST.
         command: The bash command to execute. Always use absolute paths for files and directories.
     """
-    # TODO: get sandbox ID from LangGraph's context
-    sandbox_id = "local"
-    sandbox = get_sandbox_provider().get(sandbox_id)
     try:
+        sandbox = sandbox_from_runtime(runtime)
         return sandbox.execute_command(command)
     except Exception as e:
         return f"Error: {e}"
 
 
 @tool("ls", parse_docstring=True)
-def ls_tool(description: str, path: str) -> str:
+def ls_tool(runtime: ToolRuntime[ContextT, ThreadState], description: str, path: str) -> str:
     """List the contents of a directory up to 2 levels deep in tree format.
 
     Args:
-        description: Explain why you are listing this directory in short words.
+        description: Explain why you are listing this directory in short words. ALWAYS PROVIDE THIS PARAMETER FIRST.
         path: The **absolute** path to the directory to list.
     """
     try:
-        # TODO: get sandbox ID from LangGraph's context
+        sandbox = sandbox_from_runtime(runtime)
-        sandbox = get_sandbox_provider().get("local")
         children = sandbox.list_dir(path)
         if not children:
             return "(empty)"
@@ -45,6 +60,7 @@ def ls_tool(description: str, path: str) -> str:
 
 @tool("read_file", parse_docstring=True)
 def read_file_tool(
+    runtime: ToolRuntime[ContextT, ThreadState],
     description: str,
     path: str,
     view_range: tuple[int, int] | None = None,
@@ -52,13 +68,12 @@ def read_file_tool(
     """Read the contents of a text file.
 
     Args:
-        description: Explain why you are viewing this file in short words.
+        description: Explain why you are viewing this file in short words. ALWAYS PROVIDE THIS PARAMETER FIRST.
         path: The **absolute** path to the file to read.
         view_range: The range of lines to view. The range is inclusive and starts at 1. For example, (1, 10) will view the first 10 lines of the file.
     """
     try:
-        # TODO: get sandbox ID from LangGraph's context
+        sandbox = sandbox_from_runtime(runtime)
-        sandbox = get_sandbox_provider().get("local")
         content = sandbox.read_file(path)
         if not content:
             return "(empty)"
@@ -72,6 +87,7 @@ def read_file_tool(
 
 @tool("write_file", parse_docstring=True)
 def write_file_tool(
+    runtime: ToolRuntime[ContextT, ThreadState],
     description: str,
     path: str,
     content: str,
@@ -80,13 +96,12 @@ def write_file_tool(
     """Write text content to a file.
 
     Args:
-        description: Explain why you are writing to this file in short words.
+        description: Explain why you are writing to this file in short words. ALWAYS PROVIDE THIS PARAMETER FIRST.
-        path: The **absolute** path to the file to write to.
+        path: The **absolute** path to the file to write to. ALWAYS PROVIDE THIS PARAMETER SECOND.
-        content: The content to write to the file.
+        content: The content to write to the file. ALWAYS PROVIDE THIS PARAMETER THIRD.
     """
     try:
-        # TODO: get sandbox ID from LangGraph's context
+        sandbox = sandbox_from_runtime(runtime)
-        sandbox = get_sandbox_provider().get("local")
         sandbox.write_file(path, content, append)
         return "OK"
     except Exception as e:
@@ -95,6 +110,7 @@ def write_file_tool(
 
 @tool("str_replace", parse_docstring=True)
 def str_replace_tool(
+    runtime: ToolRuntime[ContextT, ThreadState],
     description: str,
     path: str,
     old_str: str,
@@ -105,15 +121,14 @@ def str_replace_tool(
     If `replace_all` is False (default), the substring to replace must appear **exactly once** in the file.
 
     Args:
-        description: Explain why you are replacing the substring in short words.
+        description: Explain why you are replacing the substring in short words. ALWAYS PROVIDE THIS PARAMETER FIRST.
-        path: The **absolute** path to the file to replace the substring in.
+        path: The **absolute** path to the file to replace the substring in. ALWAYS PROVIDE THIS PARAMETER SECOND.
-        old_str: The substring to replace.
+        old_str: The substring to replace. ALWAYS PROVIDE THIS PARAMETER THIRD.
-        new_str: The new substring.
+        new_str: The new substring. ALWAYS PROVIDE THIS PARAMETER FOURTH.
         replace_all: Whether to replace all occurrences of the substring. If False, only the first occurrence will be replaced. Default is False.
     """
     try:
-        # TODO: get sandbox ID from LangGraph's context
+        sandbox = sandbox_from_runtime(runtime)
-        sandbox = get_sandbox_provider().get("local")
         content = sandbox.read_file(path)
         if not content:
             return "OK"