Enables optional live translation of source strings into multiple target locales using an OpenAI-compatible API endpoint before running localization linting, with configurable base URL, API key, and model.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@i18n-locale-mcp lint my German translation for errors: Gesamt: 1,234 EUR"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
A zero-dependency MCP server that gives any AI agent a localization QA toolkit. Deterministic, offline-capable, and safe to run in CI.
Works with Claude Desktop, Cursor, Dify, AutoGPT, and any MCP-compatible client.
Shipping a product in 20 locales is easy; shipping it correctly is not. Agents and devs
constantly produce 1,234 in German, 03/25 in French, missing {name} placeholders, or
untranslated brand terms. This server catches those deterministically — no API key needed.
Related MCP server: BeLikeNative Grammar Server
Tool | What it does | Network |
| Locale formatting rules (quotes, separators, dates, RTL, formality) for 20 locales | none |
| Accented + expanded pseudolocale to catch hard-coded strings & truncation | none |
| Number/date separators, quote style, CJK punctuation, RTL bidi, placeholder parity, length budget | none |
| Enforce terminology + protect brand terms across targets | none |
| Translate to N locales, then lint — or emit structured translation jobs if no provider is set | optional |
localize never fabricates translations: without a provider configured it returns
machine-readable translation jobs (source + rules + placeholders) for you to execute.
git clone <repo> && cd i18n-mcp
node index.js --list-tools # sanity check
node test/smoke.mjs # 11 deterministic checksRequires Node.js >= 18. No dependencies.
Add to claude_desktop_config.json (or Cursor / Dify MCP settings):
{
"mcpServers": {
"i18n": {
"command": "node",
"args": ["/absolute/path/to/i18n-mcp/index.js"]
}
}
}Set an OpenAI-compatible endpoint and localize will translate before linting:
export I18N_LLM_BASE_URL="https://api.openai.com/v1"
export I18N_LLM_API_KEY="sk-..."
export I18N_LLM_MODEL="gpt-4o-mini" # optionalWithout these, localize returns providerMode: "jobs" and does zero network calls.
pseudoLocalize("Save changes") // 【Såvé çhångéš~~~~~~~~~】{ "text": "Gesamt: 1,234 EUR", "locale": "de-DE" }→ NUMBER_GROUP_SEP error: German expects . as thousands separator.
import { pseudoLocalize, lint, glossaryApply, localize } from "i18n-locale-mcp";
lint("Cherchez 03/25/2026", "fr-FR"); // DATE_ORDER error
glossaryApply([{ source: "Save", target: "Enregistrer" }],
[{ key: "btn.save", text: "Save" }]); // TERM_UNTRANSLATED
await localize("Hello {name}", ["de-DE", "ja-JP"]); // lint-ready outputnode index.js # run MCP server on stdio
node index.js --list-tools # list tools
node index.js --versionMIT
This server cannot be deployed
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