We found that AI coding agents get stuck when setting up internationalization in web apps from scratch. Too many interdependent steps - locale routing, middleware, translation files, provider wrappers, language switcher - and agents lose track of what's done and what's left.
Inspired by the Sequential Thinking MCP, we built a free MCP server that breaks i18n setup into a guided checklist the agent follows step by step. Connect it to your AI agent, type "Set up i18n," and the full setup completes in minutes.
What the MCP provides#
The server exposes four tools to the AI agent:
| Tool | Purpose |
|---|---|
i18n_checklist | A step-by-step implementation guide that coordinates the entire setup. The agent calls it at each step to know what to do next. |
get_project_context | Captures the project's architecture - framework, router, directory structure - to inform the implementation strategy. |
get_framework_docs | Retrieves official framework documentation for the detected framework (Next.js, React Router, TanStack Start). |
get_i18n_library_docs | Retrieves documentation for i18n libraries (e.g., react-intl) used during provider and component setup. |
The i18n_checklist tool is the coordinator. It walks the agent through 13 steps - from project analysis through locale routing, translation setup, language switcher, and build validation. Each step tells the agent exactly what to implement and which tools to call.
What gets implemented#
A typical MCP-guided setup produces:
- Locale-aware routes - URLs prefixed with the active locale (
/en/about,/es/about) - Language switcher - A UI component for switching between supported locales
- Locale detection - Automatic detection of the user's preferred language
- Translation infrastructure - Provider setup, translation files, and helper functions
Supported frameworks#
| Framework | Versions |
|---|---|
| Next.js App Router | v13-16 |
| Next.js Pages Router | v13-16 |
| TanStack Start | v1 |
| React Router | v7 |
Usage#
Once the MCP is connected to your AI coding assistant, prompt it:
Set up i18n
Or be specific about locales:
Set up i18n with the following locales: en, es, and pt-BR. The default locale is "en".
The agent calls i18n_checklist to start, then follows the guided steps - calling the other tools as needed. The result is a working i18n setup tailored to your framework and project structure.
AI-assisted coding is inherently non-deterministic. The MCP improves consistency through its checklist-driven approach, but exact results may vary between runs.