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## 1.31.0

**`(feat):`** Add support for SDK variables (`x-fern-sdk-variables` / `variables` in `api.yml`).
Each variable is exposed as an optional keyword on the root client (e.g.
`Client.new(target_account_sid: "AC...")`); path parameters bound to a variable are
removed from the endpoint methods and request classes, and the value is read from
the client instead. String variables declared with an `env` fall back to
`ENV.fetch("<ENV_VAR>", nil)` when the keyword is omitted, and endpoints raise an
`ArgumentError` with a clear message when a required variable is still unset.