# modal.parameter | Modal Docs

- **URL:** https://modal.com/docs/sdk/py/latest/modal.parameter
- **Summary:** Used to specify options for modal.cls parameters, similar to dataclass.field for dataclasses

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modal.parameter
===============

    parameter(*, default=_no_default, init=True)

Used to specify options for modal.cls parameters, similar to dataclass.field for dataclasses

    class A:
        a: str = modal.parameter()

If `init=False` is specified, the field is not considered a parameter for the Modal class and not used in the synthesized constructor. This can be used to optionally annotate the type of a field that’s used internally, for example values being set by @enter lifecycle methods, without breaking type checkers, but it has no runtime effect on the class.

[modal.parameter](https://modal.com/docs/sdk/py/latest/modal.parameter#modalparameter)