Default Parameter

The default values of Parameter can be configured via App.default_parameter.

For example, to disable the negative flag feature across your entire app:

from cyclopts import App, Parameter

app = App(default_parameter=Parameter(negative=()))

@app.command
def foo(*, flag: bool):
    pass

app()

Consequently, --no-flag is no longer provided:

$ my-script foo --help
Usage: my-script foo [ARGS] [OPTIONS]

╭─ Parameters ──────────────────────────────────────────────────╮
│ *  --flag  [required]                                         │
╰───────────────────────────────────────────────────────────────╯

Explicitly setting negative in the function signature overrides this configuration and works as expected:

@app.command
def foo(*, flag: Annotated[bool, Parameter(negative="--anti-flag")]):
    pass

$ my-script foo --help
Usage: my-script foo [ARGS] [OPTIONS]

╭─ Parameters ──────────────────────────────────────────────────╮
│ *  --flag,--anti-flag  [required]                             │
╰───────────────────────────────────────────────────────────────╯

Resolution Order

When resolving what the Parameter values for an individual function parameter should be, explicitly set attributes of higher priority Parameters override lower priority Parameters. The resolution order is as follows:

Highest Priority: Parameter-annotated command function signature Annotated[..., Parameter()].
Group.default_parameter that the parameter belongs to.
App.default_parameter of the app that registered the command.
Group.default_parameter of the app that the function belongs to.
Lowest Priority: (2-4) recursively of the parenting app call-chain.

Any of Parameter's fields can be set to None to revert back to the true-original Cyclopts default. All App/Group/Parameter default_parameter values default to None.