diff --git a/src/ollama_cli/tools/filesystem.py b/src/ollama_cli/tools/filesystem.py
index ebb02a9..6051c63 100644
--- a/src/ollama_cli/tools/filesystem.py
+++ b/src/ollama_cli/tools/filesystem.py
@@ -27,7 +27,9 @@ def read_file(path: str) -> str:
 def write_file(path: str, content: str) -> str:
     try:
         expanded_path = os.path.expanduser(path)
-        os.makedirs(os.path.dirname(expanded_path), exist_ok=True)
+        dir_name = os.path.dirname(expanded_path)
+        if dir_name:
+            os.makedirs(dir_name, exist_ok=True)
         with open(expanded_path, 'w') as f:
             f.write(content)
         return f"Successfully written to {path}"
diff --git a/tests/test_all.py b/tests/test_all.py
new file mode 100644
index 0000000..eb99c04
--- /dev/null
+++ b/tests/test_all.py
@@ -0,0 +1,133 @@
+import unittest
+import os
+import sys
+import json
+from pathlib import Path
+
+# Add src to path
+sys.path.append(str(Path(__file__).parent.parent / "src"))
+
+from ollama_cli.core.config import load_config, DEFAULT_CONFIG
+from ollama_cli.core.sessions import save_session, load_session, list_sessions
+from ollama_cli.tools.base import registry
+import ollama_cli.tools.filesystem as fs
+import ollama_cli.tools.system as system
+import ollama_cli.tools.code as code
+import ollama_cli.tools.knowledge as kb
+import ollama_cli.tools.memory as memory
+
+import ollama_cli.tools.execution as execution
+import ollama_cli.tools.media as media
+from unittest.mock import patch, MagicMock
+
+class TestOllamaCLI(unittest.TestCase):
+    def test_run_python(self):
+        """Test Python execution tool"""
+        code_str = "print(1 + 1)"
+        res = execution.run_python(code_str)
+        self.assertIn("Success", res)
+        self.assertIn("2", res)
+
+    @patch('requests.get')
+    @patch('requests.post')
+    def test_generate_image_mock(self, mock_post, mock_get):
+        """Test image generation logic (mocked)"""
+        # Mock server is up
+        mock_get.return_value.status_code = 200
+        # Mock successful queue
+        mock_post.return_value.status_code = 200
+        mock_post.return_value.json.return_value = {"prompt_id": "mock_id"}
+        
+        # We need to mock websocket or skip the monitoring part for unit test
+        with patch('websocket.WebSocket') as mock_ws:
+            # Short circuit the monitoring loop by making recv return empty
+            mock_ws.return_value.recv.return_value = None
+            res = media.generate_image("a test prompt")
+            self.assertIn("Image generation finished", res)
+
+    def test_config_loading(self):
+        """Test if config loads and has defaults"""
+        cfg = load_config()
+        self.assertIn("ollama_url", cfg)
+        self.assertIn("comfy_url", cfg)
+
+    def test_session_management(self):
+        """Test saving and loading sessions"""
+        test_msgs = [{"role": "user", "content": "test message"}]
+        name = "test_unit_session"
+        path = save_session(test_msgs, name)
+        self.assertTrue(os.path.exists(path))
+        
+        loaded = load_session(name)
+        self.assertEqual(loaded, test_msgs)
+        
+        sessions = list_sessions()
+        self.assertIn(name, sessions)
+        
+        # Cleanup
+        os.remove(path)
+
+    def test_tool_registry(self):
+        """Test if all tools are registered"""
+        tools = [t["name"] for t in registry.list_tools()]
+        expected = [
+            "read_file", "write_file", "list_directory", "grep_search", "get_tree",
+            "execute_bash", "get_env_info",
+            "code_analyze_file", "generate_readme", "run_linter", "replace_text",
+            "kb_add", "kb_search",
+            "remember_fact", "recall_facts", "clear_memory"
+        ]
+        for e in expected:
+            self.assertIn(e, tools, f"Tool {e} missing from registry")
+
+    def test_filesystem_tools(self):
+        """Test core filesystem tools"""
+        test_file = "test_fs_tool.txt"
+        content = "hello world"
+        
+        # Write
+        res = fs.write_file(test_file, content)
+        self.assertIn("Successfully", res)
+        
+        # Read
+        read_res = fs.read_file(test_file)
+        self.assertEqual(read_res, content)
+        
+        # Grep (search directly in the file path to be efficient)
+        grep_res = fs.grep_search("hello", test_file, "*")
+        self.assertIn("hello world", grep_res)
+        
+        # Cleanup
+        os.remove(test_file)
+
+    def test_code_tools(self):
+        """Test code manipulation tools"""
+        test_file = "test_code.py"
+        code_content = "def hello():\n    print('hi')"
+        fs.write_file(test_file, code_content)
+        
+        # Replace
+        code.replace_text(test_file, "'hi'", "'hello'")
+        new_content = fs.read_file(test_file)
+        self.assertIn("'hello'", new_content)
+        
+        # Analyze
+        analysis = code.code_analyze_file(test_file)
+        self.assertIn("Functions: 1", analysis)
+        
+        # Cleanup
+        os.remove(test_file)
+
+    def test_memory_tools(self):
+        """Test project memory tools"""
+        memory.clear_memory()
+        fact = "Unit test is running"
+        memory.remember_fact(fact)
+        
+        recall = memory.recall_facts()
+        self.assertIn(fact, recall)
+        
+        memory.clear_memory()
+
+if __name__ == "__main__":
+    unittest.main()