Reflection (Reference)

Models and classes provide built-in reflection helpers for runtime introspection.

__class_name__() -> str

Returns the type's name as a string.

model User:
    name: str

def main() -> None:
    u = User(name="Alice")
    println(u.__class_name__())  # "User"

__fields__() -> FrozenList[FieldInfo]

Returns field metadata for the type.

model User:
    name: str
    email: str

def main() -> None:
    u = User(name="Alice", email="alice@example.com")
    for info in u.__fields__():
        println(f"{info.name}: {info.type_name}")

FieldInfo structure

Each FieldInfo record contains:

Field	Type	Description
name	FrozenStr	Canonical Incan field identifier
alias	Option[FrozenStr]	Wire name, if set via [alias="..."]
description	Option[FrozenStr]	Documentation string, if set via [description="..."]
wire_name	FrozenStr	Effective wire name (alias if present, else canonical name)
type_name	FrozenStr	Incan type display (e.g. "str", "int", "Option[str]")
has_default	bool	Whether the field has a default value
extra	FrozenDict[FrozenStr, FrozenStr]	Reserved for future metadata; always empty in current version

Notes:

• Field metadata like [alias="..."] and [description="..."] is model-only.
• For a class, FieldInfo.alias and FieldInfo.description are always None and FieldInfo.wire_name == FieldInfo.name.

Common patterns

If you only need canonical field names:

field_names = [f.name for f in model.__fields__()]

Check if a field exists:

has_email = any(f.name == "email" for f in user.__fields__())