diff --git a/scripts/patch-env-file.py b/scripts/patch-env-file.py
new file mode 100644
index 0000000..a6d893c
--- /dev/null
+++ b/scripts/patch-env-file.py
@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+from pathlib import Path
+from ruamel.yaml import YAML
+from ruamel.yaml.comments import CommentedSeq
+import sys
+
+yaml = YAML()
+yaml.preserve_quotes = True
+yaml.indent(mapping=2, sequence=4, offset=2)
+
+def ensure_env_file(service: dict, env_path: str = ".env") -> bool:
+    """
+    Ensure the service has:
+      env_file:
+        - .env
+
+    Returns True if the service was modified, else False.
+    """
+    changed = False
+
+    if "env_file" not in service:
+        seq = CommentedSeq()
+        seq.append(env_path)
+        service["env_file"] = seq
+        return True
+
+    env_file = service["env_file"]
+
+    if isinstance(env_file, str):
+        if env_file != env_path:
+            seq = CommentedSeq()
+            seq.append(env_file)
+            seq.append(env_path)
+            service["env_file"] = seq
+            changed = True
+
+    elif isinstance(env_file, list):
+        if env_path not in env_file:
+            env_file.append(env_path)
+            changed = True
+
+    else:
+        raise TypeError(f"Unsupported env_file type: {type(env_file).__name__}")
+
+    return changed
+
+
+def patch_file(path: Path, env_path: str = ".env") -> bool:
+    with path.open("r") as f:
+        data = yaml.load(f)
+
+    if not isinstance(data, dict) or "services" not in data:
+        print(f"[skip] {path}: no services section")
+        return False
+
+    services = data["services"]
+    changed = False
+
+    for service_name, service_def in services.items():
+        if not isinstance(service_def, dict):
+            print(f"[skip] {path}: service '{service_name}' is not a mapping")
+            continue
+
+        if ensure_env_file(service_def, env_path):
+            changed = True
+            print(f"[patched] {path}: service '{service_name}'")
+
+    if changed:
+        with path.open("w") as f:
+            yaml.dump(data, f)
+
+    return changed
+
+
+def main():
+    if len(sys.argv) < 2:
+        print(f"Usage: {sys.argv[0]} FILE [FILE ...]")
+        sys.exit(1)
+
+    paths = [Path(arg) for arg in sys.argv[1:]]
+    any_changed = False
+
+    for path in paths:
+        if not path.exists():
+            print(f"[error] {path}: file does not exist")
+            continue
+
+        try:
+            changed = patch_file(path)
+            if changed:
+                any_changed = True
+            else:
+                print(f"[ok] {path}: already patched or nothing to do")
+        except Exception as e:
+            print(f"[error] {path}: {e}")
+
+    sys.exit(0 if any_changed else 0)
+
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file