Extensions

MCP Connector

Model Context Protocol (MCP) is a standard designed to provide Large Language Model (LLM) agents with a way to communicate with the outside world through standardized APIs. In this article, you'll learn how to connect Claude, Cursor, VS Code and other AI clients to the SimpleLocalize MCP connector.

Looking for an overview of all tools, supported clients and example prompts? See the MCP server for localization page.

About the integration

SimpleLocalize hosts the MCP connector for you, so there is nothing to install or run on your machine. You add one URL to your AI client, sign in with your SimpleLocalize account and choose which projects and tools the app can use. It allows you to ask an AI agent to add translation keys from your code to SimpleLocalize, update existing keys, and manage translations using natural language prompts.

Server URL

https://api.simplelocalize.io/mcp

The server uses the Streamable HTTP transport and OAuth sign-in, supported by Claude, Claude Code, Cursor, VS Code and most MCP clients.

Connect your AI client

Claude

In Claude (web or desktop app), go to Settings > Connectors, click Add custom connector and paste the server URL. Click Connect and sign in with your SimpleLocalize account.

Claude Code

Run the following command in your terminal, then type /mcp in Claude Code and choose Authenticate:

claude mcp add --transport http simplelocalize https://api.simplelocalize.io/mcp

Cursor, LM Studio and other clients

Add the server to the MCP configuration of your client, for example .cursor/mcp.json:

{
  "mcpServers": {
    "simplelocalize": {
      "url": "https://api.simplelocalize.io/mcp"
    }
  }
}

VS Code and GitHub Copilot

Add the server to .vscode/mcp.json:

{
  "servers": {
    "simplelocalize": {
      "type": "http",
      "url": "https://api.simplelocalize.io/mcp"
    }
  }
}

Choose projects and tools

When the client connects for the first time, SimpleLocalize opens a sign-in page where you choose what the app can do:

  • All projects: the app can work on all your projects, including ones you create later. Turn it off to pick specific projects.
  • All tools: the app can use every tool your role allows, including tools added later. Turn it off to pick groups of tools or single tools.

The app always works with your permissions in each project. For example, if you are a translator in a project, the app can use only the tools that translators are allowed to use there.

Manage connected apps

Every app you connect is listed in Security > Connected apps. From there you can change the projects and tools of an app or disconnect it. Changing your password disconnects all apps.

Removed projects and tools stop working right away. The app may need a new chat to see tools you added.

Clients without OAuth sign-in

If your client can't sign in with OAuth, you can authenticate with a header instead:

  • Authorization: Bearer <personal access token> works with all your projects. The agent finds the project token with the list_projects tool. You can create a personal access token in Security > Personal Access Tokens.
  • X-SimpleLocalize-Token: <project API key> works with a single project. You can find the key in Project settings > Credentials.
{
  "mcpServers": {
    "simplelocalize": {
      "url": "https://api.simplelocalize.io/mcp",
      "headers": {
        "X-SimpleLocalize-Token": "SIMPLELOCALIZE_API_KEY"
      }
    }
  }
}

Available tools

  • Managing translation keys
  • Managing translations
  • Comments and translation suggestions
  • Uploading screenshots
  • Auto-translation
  • Activity, running jobs and members activity
  • Glossary management
  • Tags, languages, customer management
  • Hosting environments
  • Importing and exporting translation files
  • QA checks
  • Creating projects and checking your role in a project
  • Inviting and removing project contributors (paid plans)

Usage

You can now ask AI agent to add translation keys from your code to SimpleLocalize using prompts like:

Localize this component and update it to SimpleLocalize

or

Add all translation keys together with translations to SimpleLocalize

Migrating from the npm package

The @simplelocalize/simplelocalize-mcp package, started with npx, is deprecated. It still works, but new tools and fixes are released only on the hosted server. To migrate, replace the npx entry in your MCP configuration with the server URL above.

Extension support

SimpleLocalize Extension for VS Code is also compatible with the newest version of Cursor AI.

Last updated: November 02, 2026