typeddicts_required error

Required / NotRequired used in an invalid context

PEP 655 and the typing spec restrict RequiredT and NotRequiredT to:

- Annotations of TypedDict fields

Using them outside of a TypedDict body (in regular classes, function parameters, variable annotations, etc.) is an error.

Additionally, nesting Required or NotRequired inside each other is forbidden even within a TypedDict.

class NotTypedDict:
    x: Required[int]       # E0035 — not a TypedDict

def func(x: NotRequired[int]) -> None:   # E0035 — not a TypedDict field
    ...

class TD(TypedDict):
    a: Required[Required[int]]  # E0035 — nested Required

How to handle it

Every rule is on by default — strict is the default, not a cage. You can dial typeddicts_required down per-file or per-path from your editor or pyproject.toml, or fix the code so it type-checks. See the Type System rules and the complete diagnostic reference.

Canonical URL: https://www.basilisk-python.dev/errors/typeddicts_required