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## 4.17.0

**`(feat):`** Add opt-in `allowUserAgentAppInfo` config. When enabled, the generated client's builder exposes
an `appInfo(name, version, comment)` option whose product token is appended to the `User-Agent`
header the SDK would otherwise send (`{sdk}/{version} ... {name}/{version} ({comment})`),
following RFC 9110. Disabled by default, so existing generated output is unchanged, and it
composes with `includePlatformHeaders`, the `runtime-version` jar-manifest path, the configured
`user-agent` template value, and the default `{coordinate}/{version}`. Caller-supplied values are
trimmed and sanitized (name/version percent-encoded to RFC 7230 tchars; comment delimiters,
control characters and any non-ASCII characters percent-encoded as UTF-8 bytes so OkHttp's header
validation never rejects them), so untrusted values cannot inject header content. Still overridable
by an explicit `User-Agent` and suppressed by `omit-fern-headers`.