diff --git a/lang_agent/fs_bkends/base.py b/lang_agent/fs_bkends/base.py
index 0ee0f7f..3b03f30 100644
--- a/lang_agent/fs_bkends/base.py
+++ b/lang_agent/fs_bkends/base.py
@@ -1,8 +1,10 @@
-from dataclasses import dataclass, field, is_dataclass
+import os
+from dataclasses import dataclass
 from typing import Any
-import tyro
-import os.path as osp
 from abc import ABC, abstractmethod
+from loguru import logger
+
+from lang_agent.config import InstantiateConfig
 
 
 class BaseFilesystemBackend(ABC):
@@ -25,4 +27,25 @@ class BaseFilesystemBackend(ABC):
         if hasattr(self.config, "rt_skills_dir"):
             return {"skills" : [self.config.rt_skills_dir]}
         else:
-            return {}
\ No newline at end of file
+            return {}
+
+
+@dataclass
+class FilesystemBackendConfig(InstantiateConfig):
+    """
+    Shared filesystem backend config behavior.
+    If subclasses define these fields, this hook ensures they exist:
+      - skills_dir
+      - workspace_dir
+    """
+
+    def _ensure_dir_if_present(self, attr_name: str) -> None:
+        path = getattr(self, attr_name, None)
+        if not isinstance(path, str) or not path.strip():
+            return
+        os.makedirs(path, exist_ok=True)
+        logger.info(f"Ensured {attr_name} exists: {path}")
+
+    def __post_init__(self) -> None:
+        self._ensure_dir_if_present("skills_dir")
+        self._ensure_dir_if_present("workspace_dir")
\ No newline at end of file
diff --git a/lang_agent/fs_bkends/daytona_sandbox.py b/lang_agent/fs_bkends/daytona_sandbox.py
index e1ae07d..ee74e0a 100644
--- a/lang_agent/fs_bkends/daytona_sandbox.py
+++ b/lang_agent/fs_bkends/daytona_sandbox.py
@@ -8,13 +8,12 @@ from loguru import logger
 from daytona import Daytona, DaytonaConfig, FileUpload
 from langchain_daytona import DaytonaSandbox
 
-from lang_agent.config import InstantiateConfig
-from lang_agent.fs_bkends import BaseFilesystemBackend
+from lang_agent.fs_bkends.base import BaseFilesystemBackend, FilesystemBackendConfig
 
 
 @tyro.conf.configure(tyro.conf.SuppressFixed)
 @dataclass
-class DaytonaSandboxConfig(InstantiateConfig):
+class DaytonaSandboxConfig(FilesystemBackendConfig):
     _target: Type = field(default_factory=lambda: DaytonaSandboxBk)
 
     api_key: Optional[str] = None
@@ -27,6 +26,7 @@ class DaytonaSandboxConfig(InstantiateConfig):
     """runtime skills path inside the sandbox (auto-set from sandbox workdir)"""
 
     def __post_init__(self):
+        super().__post_init__()
         if self.api_key is None:
             self.api_key = os.environ.get("DAYTONA_API_KEY")
             if self.api_key is None:
diff --git a/lang_agent/fs_bkends/localshell.py b/lang_agent/fs_bkends/localshell.py
index 3af8e0f..88113d9 100644
--- a/lang_agent/fs_bkends/localshell.py
+++ b/lang_agent/fs_bkends/localshell.py
@@ -1,21 +1,16 @@
-from dataclasses import dataclass, field, is_dataclass
-from typing import Type, TypedDict, Literal, Dict, List, Tuple, Optional
+from dataclasses import dataclass, field
+from typing import Type
 import tyro
-import os.path as osp
-from abc import ABC, abstractmethod
-import glob
 from loguru import logger
 
-from deepagents.backends.utils import create_file_data
 from deepagents.backends import LocalShellBackend
 
-from lang_agent.config import InstantiateConfig
-from lang_agent.fs_bkends import BaseFilesystemBackend
+from lang_agent.fs_bkends.base import BaseFilesystemBackend, FilesystemBackendConfig
 
 
 @tyro.conf.configure(tyro.conf.SuppressFixed)
 @dataclass
-class LocalShellConfig(InstantiateConfig):
+class LocalShellConfig(FilesystemBackendConfig):
     _target:Type = field(default_factory=lambda:LocalShell)
 
     workspace_dir:str = "./workspace"
diff --git a/lang_agent/fs_bkends/statebk.py b/lang_agent/fs_bkends/statebk.py
index 6176980..2f1309c 100644
--- a/lang_agent/fs_bkends/statebk.py
+++ b/lang_agent/fs_bkends/statebk.py
@@ -1,16 +1,14 @@
-from dataclasses import dataclass, field, is_dataclass
-from typing import Type, TypedDict, Literal, Dict, List, Tuple, Optional
+from dataclasses import dataclass, field
+from typing import Type
 import tyro
 import os.path as osp
-from abc import ABC, abstractmethod
 import glob
 from loguru import logger
 
 from deepagents.backends.utils import create_file_data
 from deepagents.backends import StateBackend
 
-from lang_agent.config import InstantiateConfig
-from lang_agent.fs_bkends import BaseFilesystemBackend
+from lang_agent.fs_bkends.base import BaseFilesystemBackend, FilesystemBackendConfig
 
 def read_as_utf8(file_path:str):
     with open(file_path, "r", encoding="utf-8") as f:
@@ -31,7 +29,7 @@ def build_skill_fs_dict(skill_dir:str, virt_path:str="/skills"):
 
 @tyro.conf.configure(tyro.conf.SuppressFixed)
 @dataclass
-class StateBkConfig(InstantiateConfig):
+class StateBkConfig(FilesystemBackendConfig):
     _target:Type = field(default_factory=lambda:StateBk)
 
     skills_dir:str = "./assets/skills"
@@ -40,10 +38,6 @@ class StateBkConfig(InstantiateConfig):
     rt_skills_dir:str = "/skills"
     """path to directory with skills in runtime directory"""
 
-    def __post_init__(self):
-        err_msg = f"{self.skills_dir} does not exist"
-        assert osp.exists(self.skills_dir), err_msg
-
 
 class StateBk(BaseFilesystemBackend):
     def __init__(self, config:StateBkConfig):