# I18n MCP

Max Prilutskiy·Updated 2 months ago·2 min read

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](https://github.com/modelcontextprotocol/servers/tree/main/src/sequentialthinking), 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.

## Next Steps

[Setup  
 Connect the MCP to your AI coding assistant](/content/en/docs/react/mcp/setup/index.html)  
 [Claude Code  
 Set up in Claude Code](/content/en/docs/react/mcp/claude-code/index.html)  
 [Cursor  
 Set up in Cursor](/content/en/docs/react/mcp/cursor/index.html)  
 [GitHub Copilot  
 Set up in GitHub Copilot Agents](/content/en/docs/react/mcp/github-copilot/index.html)