diff --git a/funcs_common.py b/funcs_common.py
index 7bd5789..c05db3e 100644
--- a/funcs_common.py
+++ b/funcs_common.py
@@ -5,8 +5,13 @@ Code shared between various `funcs_*` modules.
 
 import typing as _t
 
+import re as _re
+
 from server import PromptServer as _PromptServer
 
+from .enums import T as _T
+
+
 def _show_text_on_node(text: str = None, unique_id: str = None):
 	if not text:
 		# TODO: Planned for the future - currently, there's no point removing the text since it's box is shown anyway
@@ -16,3 +21,61 @@ def _show_text_on_node(text: str = None, unique_id: str = None):
 
 	# Snatched from: https://github.com/comfyanonymous/ComfyUI/blob/27870ec3c30e56be9707d89a120eb7f0e2836be1/comfy_extras/nodes_images.py#L581-L582
 	_PromptServer.instance.send_progress_text(text, unique_id)
+
+
+_re_valid_key_match = _re.compile("[a-zA-Z_][a-zA-Z_0-9]*$").match
+_re_starting_digits_match = _re.compile("[0-9]+").match
+
+
+def _validate_key(key: str, errors_dict: _t.Dict[_t.Any, str]) -> _t.Union[str, None]:
+	"""Verify that the given string can be a key. Otherwise, append a message to `errors_dict`."""
+	if not isinstance(key, str):
+		errors_dict[key] = f"Not a valid key (string name): {key!r}"
+		return None
+	key = str(key).strip()
+	if not key:
+		errors_dict[key] = f"Key (string name) can't be empty. Got: {key!r}"
+		return None
+	if not _re_valid_key_match(key):
+		if _re_starting_digits_match(key):
+			errors_dict[key] = f"Key (string name) can't start with a digit. Got: {key!r}"
+		else:
+			errors_dict[key] = f"Key (string name) must contain only numbers, latin letters and underscores. Got: {key!r}"
+		return None
+	return key
+
+
+def _raise_from_errors_dict(
+	errors_dict: _t.Dict[_t.Any, str],
+	single_error_format: str = '{}',
+	multi_errors_format: str = "Invalid keys (string names):\n{}",
+):
+	if not errors_dict:
+		return
+
+	if len(errors_dict) == 1:
+		msg = single_error_format.format(next(iter(errors_dict.values())))
+	else:
+		msg = multi_errors_format.format('\n'.join(repr(x) for x in errors_dict.keys()))
+	raise KeyError(msg)
+
+
+def _verify_input_dict(input_dict: _t.Dict[str, _T] = None) -> _t.Dict[str, _T]:
+	"""
+	Verify input dict to have only valid keys. Raises errors if invalid ones found.
+	Always returns a new dict instance (shallow copy if non-empty dict passed).
+	"""
+	if input_dict is None:
+		return dict()
+	if not isinstance(input_dict, dict):
+		raise TypeError(f"Input-dict isn't a dict. Got: {input_dict!r}")
+
+	errors_dict: _t.Dict[_t.Any, str] = dict()
+	for key in input_dict.keys():
+		_validate_key(key, errors_dict)
+
+	_raise_from_errors_dict(
+		errors_dict,
+		"Invalid input-dict:\n{}", "Invalid keys (string names) in input-dict:\n{}"
+	)
+	return dict(input_dict)