Changelog

July 10, 2026

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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.