API Docs – Language Settings

API Development And
Integration Guide

Language Settings

Overview

The Accept-Language HTTP header lets clients specify their preferred locale (e.g., en-US). WUPEX uses this header to tailor localization, including translated messages, date/time, and currency formats.

How Accept-Language Works

It's part of standard HTTP content negotiation, widely supported across browsers and APIs using tags like en-US, fr-FR, or even weighted lists (e.g., en-US, en;q=0.9) community.fitbit.com+3localizely.com+3googlecloudcommunity.com+3stackoverflow.com+7developer.mozilla.org+7stackoverflow.com+7.
WUPEX looks at the primary tag (first in the list) and responds in that locale if supported. If not, it defaults to English (en-US) or the closest available match.
Use it in every request header to ensure consistent localization of user-facing strings and response formats:

http

Accept-Language: en-US

Examples

http

Accept-Language: en-US

http

Accept-Language: fr-FR, en-US;q=0.8

http

Accept-Language: es-MX

Best Practices

Developer Integration Tips

Include Accept-Language: en-US (or user’s locale) in all API requests.
Implement user preferences in applications so that requests automatically include the correct locale.
Use the response to render UI strings and data formats (mm/dd/yyyy vs dd/mm/yyyy, currency format, etc.).
For multilingual product catalogs or error messages, always request via Accept-Language.