What problem does it solve? Building a multi-language app requires locale-aware URLs, a reliable locale resolution strategy, and integration with a message library like react-intl. This Skill provides the patterns to mount routes under an optional locale prefix, resolve the active locale from URL, cookie, and Accept-Language headers, and wire react-intl into a React Server Components route tree. ## Core Features & Use Cases - Optional Locale Prefix Routing: Mount routes under /:locale? so the default locale lives at the bare URL while other locales get a prefix, with constraints to reject unknown locales. - Locale Resolution Chain: Resolve the active locale via URL prefix, cookie, Accept-Language header, then a default fallback, with optional middleware redirects to canonical URLs. - react-intl Integration: Load message bundles server-side and pass them to a client IntlProvider, keeping translations out of the client bundle. - Use Case: You are building a documentation site in English, British English, and French. Use this Skill to serve /, /en, and /fr variants, generate localized links with reverse(), and render translated UI strings through react-intl. ## Quick Start Use the i18n skill to add an optional locale prefix to my Rango routes and wire up react-intl with a locale resolution fallback chain.