diff --git a/opencode-container.py b/opencode-container.py
index 84a7919..2419caa 100755
--- a/opencode-container.py
+++ b/opencode-container.py
@@ -1,12 +1,20 @@
 #!/usr/bin/env python3
 
 import hashlib
+import logging
 import os
 import subprocess
 import sys
 import time
 from pathlib import Path
 
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(message)s',
+    stream=sys.stderr
+)
+logger = logging.getLogger(__name__)
+
 
 class OpenCodeContainer:
     IMAGE = "opencode-container:latest"
@@ -45,6 +53,14 @@ class OpenCodeContainer:
         # Ensure container home directory exists
         self.container_home_path.mkdir(parents=True, exist_ok=True)
 
+        # Check if this project already has a running container
+        if self.container_exists() and self.container_running():
+            logger.error(f"Project '{self.project_path.name}' already has a running OpenCode container.")
+            logger.error(f"Container name: {self.container_name}")
+            logger.error("Wait for the current instance to finish or manually stop it with:")
+            logger.error(f"  docker stop {self.container_name}")
+            sys.exit(1)
+
         # Pre-create project directory structure to prevent root-owned directories
         try:
             relative_path = self.project_path.relative_to(Path.home())
@@ -60,7 +76,7 @@ class OpenCodeContainer:
             self.create_container()
 
         if not self.start_container():
-            print("Recreating container due to failed start")
+            logger.warning("Recreating container due to failed start")
             self.remove_container()
             self.create_container()
             if not self.start_container():
@@ -83,7 +99,7 @@ class OpenCodeContainer:
         ).returncode == 0
 
     def build_image(self) -> None:
-        print(f"Building image '{self.IMAGE}' with user {self.host_username} ({self.host_uid}:{self.host_gid})")
+        logger.info(f"Building image '{self.IMAGE}' with user {self.host_username} ({self.host_uid}:{self.host_gid})")
         self._run([
             "docker", "build",
             "--build-arg", f"USERNAME={self.host_username}",
@@ -98,7 +114,7 @@ class OpenCodeContainer:
     # =========================
 
     def create_container(self) -> None:
-        print(f"Creating container '{self.container_name}'")
+        logger.info(f"Creating container '{self.container_name}'")
 
         self._run([
             "docker", "create",