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## 5.18.1

**`(fix):`** Normalize the architecture label in the structured `User-Agent` (emitted when
`include_platform_headers` is enabled) so the 64-bit x86 aliases (`x64`,
`amd64`, `x86_64`) all report as the canonical `x86_64`, keeping the value
consistent across generators.

## 5.18.0

**`(feat):`** Add opt-in support for a structured `User-Agent` header of the form
`{sdkName}/{version} ({os}; {arch}) Python/{pythonVersion}`, matching the
Twilio helper-library shape. This is gated behind the `include_platform_headers`
config option and is disabled by default. When enabled, the platform + runtime
information is consolidated into the `User-Agent` header, superseding the
default `{package}/{version}` value, and the discrete `X-Fern-Runtime` /
`X-Fern-Platform` headers are no longer emitted. The platform group and runtime
segment are dropped gracefully when they cannot be determined, and the header
remains subject to `omit_fern_headers`.