microsoft/autogen · error · ValueError
No annotation
Error message
No annotation
What it means
Error "No annotation" thrown in microsoft/autogen.
Source
Thrown at python/packages/autogen-core/src/autogen_core/_function_utils.py:316
def normalize_annotated_type(type_hint: Type[Any]) -> Type[Any]:
"""Normalize typing.Annotated types to the inner type."""
if get_origin(type_hint) is Annotated:
# Extract the inner type from Annotated
return get_args(type_hint)[0] # type: ignore
return type_hint
def args_base_model_from_signature(name: str, sig: inspect.Signature) -> Type[BaseModel]:
fields: Dict[str, tuple[Type[Any], Any]] = {}
for param_name, param in sig.parameters.items():
# This is handled externally
if param_name == "cancellation_token":
continue
if param.annotation is inspect.Parameter.empty:
raise ValueError("No annotation")
type = normalize_annotated_type(param.annotation)
description = type2description(param_name, param.annotation)
default_value = param.default if param.default is not inspect.Parameter.empty else PydanticUndefined
fields[param_name] = (type, Field(default=default_value, description=description))
return cast(BaseModel, create_model(name, **fields)) # type: ignore
View on GitHub (pinned to 027ecf0a37)
Solutions
- Add a type annotation to the parameter
Example fix
def f(x: int): ...
When it happens
Trigger: Thrown at python/packages/autogen-core/src/autogen_core/_function_utils.py:316 when the library encounters an invalid state.
Common situations: See trigger scenarios.
AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15).
Data as JSON: /api/errors/faa4530984a86a8f.
Report an issue: GitHub.