Lingui Skills

Implement internationalization with Lingui in React and JavaScript applications. Use when adding i18n, translating UI, working with Trans/useLingui/Plural, extracting messages, compiling catalogs, or when the user mentions Lingui, internationalization, i18n, translations, locales, message extraction, ICU MessageFormat, or working with .po files.

Audit a Lingui project for hardcoded user-facing strings that were never wrapped in macros. Use when asked to find untranslated, unwrapped, or hardcoded strings, to check i18n coverage, to audit what an i18n setup or migration missed, or when text renders in the source language after everything was supposedly translated.

Set up Lingui in a React framework. Use when adding Lingui to a Next.js App Router, Vite, React Router 7, Remix, or TanStack Start project, when wiring locale detection, locale-prefixed URLs, or SSR locale resolution, or when a working setup breaks after a framework or build-tool upgrade.

Add translator comments to Lingui messages so translations are accurate. Use when adding or modifying translatable messages, when strings are short or ambiguous ("Back", "Delete", "Post"), when placeholders are unclear ({count}, {name}), when deciding between comment and context, or when auditing extracted .po catalogs for missing translator context.

Diagnose and fix Lingui SWC plugin compatibility errors with Next.js, Vite, Rspack, or other SWC runtimes. Use when seeing errors like "failed to invoke plugin", "failed to run Wasm plugin transform", "Failed to deserialize program received from host", "Failed to execute SWC plugin", "out of bounds memory access", or "LayoutError" during builds with @lingui/swc-plugin — or when macros are silently not transformed (build succeeds but Trans/t render as raw untranslated output).

Migrate i18next/react-i18next projects to Lingui. Use when the user wants to replace i18next, react-i18next, useTranslation, i18n.t(), Trans i18nKey, or i18next JSON catalogs with Lingui equivalents. Covers package installation, config setup, code transformation patterns, plural migration, namespace handling, and catalog conversion.