better-i18n

name

better-i18n

description

Guides all better-i18n integration decisions — SDK selection (Next.js, React, Expo, Swift, Flutter, Remix), CDN vs GitHub workflow, AI-powered translation management via MCP tools, CLI health checks (scan, doctor, sync), Content CMS (localized models, entries, custom fields), file format conventions (flat / nested / namespaced), key naming, publish flows, and quality analytics. Use whenever building, modifying, or reviewing any localization feature — including i18n setup, adding languages, managing translation keys, publishing, or integrating AI workflows.

better-i18n — Localization infrastructure for modern apps. CMS + TMS + CDN + AI + MCP. Dashboard: https://better-i18n.com · Docs: https://docs.better-i18n.com · CDN: https://cdn.better-i18n.com · Skills: https://github.com/better-i18n/skills

Package versions

Package	Version	Install
@better-i18n/next	0.7.6	npm install @better-i18n/next@0.7.6
@better-i18n/use-intl	0.8.0	npm install @better-i18n/use-intl@0.8.0
@better-i18n/core	0.7.0	npm install @better-i18n/core@0.7.0
@better-i18n/server	0.4.0	npm install @better-i18n/server@0.4.0
@better-i18n/vite	0.2.6	npm install @better-i18n/vite@0.2.6
@better-i18n/expo	0.8.2	npm install @better-i18n/expo@0.8.2
@better-i18n/remix	0.6.2	npm install @better-i18n/remix@0.6.2
@better-i18n/sdk	3.2.1	npm install @better-i18n/sdk@3.2.1
@better-i18n/cli	0.2.6	npx @better-i18n/cli@0.2.6
@better-i18n/mcp	0.15.5	npx -y @better-i18n/mcp@0.15.5
@better-i18n/mcp-content	0.8.1	npx -y @better-i18n/mcp-content@0.8.1

Always check npm for the latest version before installing.

SDK selection

Framework	Package	Reference
Next.js (App Router or Pages Router)	@better-i18n/next	<references/sdk-next.md>
React + TanStack Router / use-intl	@better-i18n/use-intl	<references/sdk-react.md>
Vite + React (SPA or SSR)	@better-i18n/vite + use-intl	<references/sdk-react.md>
Hono / Node.js server	@better-i18n/server	<references/sdk-react.md>
Better Auth (error translation)	@better-i18n/server	<references/locale-persistence.md>
Remix / Shopify Hydrogen	@better-i18n/remix	<references/sdk-react.md>
React Native / Expo	@better-i18n/expo	<references/sdk-mobile.md>
Swift (iOS / macOS / visionOS)	BetterI18n via SPM	<references/sdk-mobile.md>
Flutter / Dart	better_i18n pub.dev	<references/sdk-mobile.md>
Headless / Vanilla JS	@better-i18n/core	<references/sdk-react.md>

Framework quick-start

Framework	Docs page
Next.js App Router	https://docs.better-i18n.com/frameworks/nextjs.mdx
TanStack Start (SSR)	https://docs.better-i18n.com/frameworks/tanstack-start.mdx
Vite + React	https://docs.better-i18n.com/frameworks/vite.mdx
Vite + React Router	https://docs.better-i18n.com/frameworks/vite/react-router.mdx
Remix / Hydrogen	https://docs.better-i18n.com/frameworks/remix.mdx
Expo / React Native	https://docs.better-i18n.com/frameworks/expo.mdx
iOS / Swift	https://docs.better-i18n.com/frameworks/ios.mdx
Flutter / Dart	https://docs.better-i18n.com/frameworks/flutter.mdx
Hono / Node.js	https://docs.better-i18n.com/frameworks/server-sdk/hono.mdx
Express / Fastify	https://docs.better-i18n.com/frameworks/server-sdk/node.mdx
Better Auth	https://docs.better-i18n.com/frameworks/server-sdk/better-auth.mdx
tRPC	https://docs.better-i18n.com/frameworks/server-sdk/trpc.mdx
Supabase Edge	https://docs.better-i18n.com/frameworks/server-sdk/supabase.mdx

Workflow selection

Task	Approach	Reference
Upload JSON files, no GitHub needed	CDN-first	<references/cdn.md>
GitHub PR-based translation sync	GitHub App + publish flow	<references/github-sync.md>
AI-assisted key and translation management	MCP tools	<references/mcp.md>
Localized CMS content (blog, docs, pages)	Content CMS + SDK	<references/content.md>
Scan codebase for hardcoded strings	CLI scan	<references/cli.md>
Check translation coverage and key sync	CLI sync / check	<references/cli.md>
Full i18n health analysis with score	CLI doctor	<references/cli.md>
Define key naming and namespace structure	Key conventions	<references/key-naming.md>
Choose JSON file format	File formats	<references/file-formats.md>
Publish translations to CDN or GitHub	Publish flows	<references/publish-and-analytics.md>
Track coverage, health trends, CDN usage	Analytics	<references/publish-and-analytics.md>
Persist locale across refreshes / auth requests	Locale persistence	<references/locale-persistence.md>
Translate Better Auth error messages	Auth + i18n	<references/locale-persistence.md>
Send app locale in fetch / auth headers	Locale headers	<references/locale-persistence.md>
Format dates, numbers, currencies, relative time	Formatting	<references/sdk-react.md>
Detect locale from country / Accept-Language	Geo detection	<references/cdn.md>
Type-safe t("key") autocomplete	TypeScript	<references/sdk-react.md>
Webhooks on publish / key change events	Outgoing webhooks	<references/publish-and-analytics.md>

Read the relevant reference before writing any code.

Critical rules (apply everywhere)

• Project identifier is always "org/project" — e.g. "acme/dashboard" or "stripe/web"
• Locale codes are lowercase BCP 47 on the CDN: "pt-BR" → "pt-br". Always call normalizeLocale() before constructing CDN paths.
• Singletons — createI18n (Next.js), createServerI18n, createRemixI18n, createI18nCore must be instantiated once at module scope. Never inside a function, request handler, or component.
• createKeys vs updateKeys — createKeys creates NEW keys only. Using it on existing keys causes phantom key accumulation (documented incident: 1,005 duplicates in one operation). Always fetch the key ID with listKeys first, then call updateKeys.
• CDN always returns HTTP 200 — check for { fallback: true } in the JSON body, not HTTP status codes.
• Default namespace → "translations" in CDN paths — the namespace "default" is stored as "translations" internally. Use null namespace for flat-key projects.
• Free to get started — all SDKs and CLI are open-source. Paid plans unlock more languages, history, and team features.