Function find_context_parameter

src/google/adk/utils/context_utils.py:67–99

Find the parameter name that has a Context type annotation. This function inspects the signature of a callable and returns the name of the first parameter that is annotated with Context or a type alias of Context (e.g., ToolContext, CallbackContext). Args: func: The callable to inspect

(func: Callable[..., Any])

@functools.lru_cache(maxsize=1024)
def find_context_parameter(func: Callable[..., Any]) -> str | None:
  """Find the parameter name that has a Context type annotation.

  This function inspects the signature of a callable and returns the name
  of the first parameter that is annotated with Context or a type alias of
  Context (e.g., ToolContext, CallbackContext).

  Args:
    func: The callable to inspect.

  Returns:
    The parameter name if found, None otherwise.
  """
  if func is None:
    return None
  try:
    signature = inspect.signature(func)
  except (ValueError, TypeError):
    return None
  # Resolve string annotations (e.g., 'Context')
  try:
    type_hints = typing.get_type_hints(func)
  except Exception:
    # get_type_hints can fail for various reasons (e.g., unresolvable forward
    # references). In such cases, we fall back to inspecting the parameter
    # annotations directly.
    type_hints = {}

  for name, param in signature.parameters.items():
    annotation = type_hints.get(name, param.annotation)
    if _is_context_type(annotation):
      return name
  return None