localize.dev MCP server

localize.dev

Ship your app in every language. localize.dev finds hardcoded UI text in your code, gives it translation keys, translates it with your app's context, writes the locale files and opens one pull request. It works with React, Next.js, React Native, Vue, Svelte, Astro, Angular, Flutter, iOS, Android, Rails, Django and Laravel.

// before                                   // after
<h1>Welcome back</h1>                       <h1>{t('auth.welcome_heading')}</h1>
<p>Hello {user.name}!</p>                   <p>{t('auth.greeting', { name: user.name })}</p>

This repository holds the agent plugins and MCP listing for the localize-dev package. Docs, pricing and API keys are at uselocalize.dev. Report problems in Issues.

Claude Code

claude plugin marketplace add ufortstephen/localize-dev
claude plugin install localize-dev@uselocalize

The plugin adds the localize MCP server and a skill that tells Claude when to use it.

Cursor

Install localize.dev from the plugin list, or add the server to .cursor/mcp.json:

{
  "mcpServers": {
    "localize": { "command": "npx", "args": ["-y", "localize-dev", "mcp"] }
  }
}

Other MCP clients (Codex, Windsurf, Cline, VS Code)

Run npx -y localize-dev mcp as a stdio server. It's listed in the MCP Registry as io.github.ufortstephen/localize-dev.

Tool	What it does	Needs a key
check	Hardcoded copy, missing and outdated translations, each with its file and line	No
config	The app's languages, locale files and i18n library	No
localize	Gives hardcoded text keys, rewrites the code and translates it	Yes
translate	Fills in missing translations in existing locale files	Yes
add_language	Adds a language and translates every message into it	Yes

Hosted server (Lovable, Bolt, v0 and other browser-based builders)

Agents that can't start a local process can connect to https://uselocalize.dev/api/mcp as a Streamable HTTP server. Clients that support OAuth sign in and you approve the connection on localize.dev; otherwise send a localize.dev API key as the bearer token (or in an x-api-key header):

{
  "mcpServers": {
    "localize": {
      "type": "http",
      "url": "https://uselocalize.dev/api/mcp",
      "headers": { "Authorization": "Bearer YOUR_API_KEY" }
    }
  }
}

It has the same tools. Each call carries the files the tool needs (files: [{ path, content }]) and returns the files to write back. Every call needs a key or an OAuth sign-in; check and config still don't count toward your plan.

API key

There's a free tier. Create a key at uselocalize.dev/dashboard/keys, then run npx localize-dev login once, or set LOCALIZE_API_KEY.

Data

check and config run on your machine and send nothing. localize, translate and add_language send the localize.dev API only the UI text being translated, the path of the file it came from and short component context, never whole files. The API translates them with a hosted model (Google Gemini, with OpenAI and Mistral as backups, through Vercel AI Gateway), which doesn't train on them. localize.dev doesn't store the source text, only a one-way fingerprint of it, and keeps the returned translations in your workspace's translation memory until you delete the workspace. The hosted server writes the files an agent sends to a temporary folder for that call and deletes them when it answers; they aren't stored or logged. Details: uselocalize.dev/privacy.

Set up a project

npx localize-dev init --agent    # MCP config, project instructions and an after-edit hook, committed for the team
npx localize-dev run -l es,fr,de # or localize the whole app from the terminal
npx localize-dev check           # in CI: fails on hardcoded copy and missing translations

The GitHub Action is ufortstephen/autolocalize-action.

License

The files in this repository (plugin manifests, skill, rule and MCP configuration) are MIT licensed: see legal/plugin-files-license.txt. The localize-dev package they run isn't open source; its license is included in the package.