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## 4.3.0

**`(feat):`** Add `clientDefault` support for headers, query parameters, and path
parameters. When a parameter has a `clientDefault` value (set via the
`x-fern-default` OpenAPI extension), the generated SDK uses that value
as a fallback when the caller does not provide one. Parameters with
`clientDefault` become optional in the wrapped request and use
`.orElse(defaultValue)` to apply the fallback.