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## 2.25.0

**`(feat):`** Add support for SDK variables (`x-fern-sdk-variables` / `variables` in `api.yml`). Each variable
becomes an optional, named constructor parameter on the root client (also settable through the
`options` array and per request). Path parameters bound to a variable are removed from endpoint
method signatures and request classes and resolved from the client instead. String variables
that declare an environment variable fall back to `getenv()` when no value is passed, and a
clear `InvalidArgumentException` is thrown when a bound variable is still unset at call time.