i1n

Your app in every language. One command.

Localization as code. Push your translation keys, AI translates to 182 languages, pull type-safe TypeScript definitions. Built for developers, AI agents, and product teams.

Free forever · No credit card · i1n.ai

Why i1n?

Traditional i18n means dozens of JSON files, zero type safety, hours of copy-pasting, and deploys that break at 2 AM. Existing tools charge $120+/mo and require browser-based workflows.

i1n is different:

• One command — i1n push --translate es,fr,ja and you're done

• Type-safe — auto-generated i1n.d.ts with full IDE autocomplete

• AI-native — MCP server for Cursor, Claude Code, Windsurf. Your agent handles i18n for you

• Zero migration — Bridge Mode wraps your existing i18next/next-intl/vue-i18n

• 6x cheaper — Free tier included. Pro at $19/mo vs Lokalise at $120/mo

📦 Install

# To use the CLI (global)
npm install -g i1n

# To use the SDK + types (in your app)
npm install i1n

# Local CLI usage (optional)
npm install -D i1n

Supports npm, pnpm, yarn, and bun.

🏁 Quick Start

# 1. Initialize (auth + auto-detect setup)
i1n init

# 2. Push your translation keys
i1n push

# 3. Pull translations + auto-generated TypeScript types
i1n pull

✨ Key Features & Commands

🛠️ i1n init

Interactive setup that prepares your workspace.

• Authenticates via API key.

• New? If you don't have a key yet, the CLI provides clear guidance on how to get started.

• Auto-detects frameworks (Next.js, Vite, Expo, Flutter, Rails, etc.).

• Saves configuration to i1n.config.json (automatically ignored via .gitignore).

• AI Orchestration: Optionally sets up rules for your AI coding tools.

⬆️ i1n push

Syncs your local translations to i1n.

• Detects new keys and source changes.

• Smart Translate: Offers to translate missing keys with a cost estimate before proceeding.

• Efficient caching layer — repeated translations cost a fraction of fresh ones.

⬇️ i1n pull

Downloads translations and generates type-safe IDs.

• Updates local locale files in your configured format.

• Generates i1n.d.ts for full IDE autocomplete.

📊 i1n limits

Real-time usage tracking.

• View your current plan and credit usage.

• Monitor active language slots and available capacity.

🧠 i1n setup-ai

Turns your IDE into a localization expert.

• Generates project-specific rules for Cursor (.mdc), Claude Code (CLAUDE.md), Windsurf, and more.

• Ensures AI agents follow your naming conventions, file structure, and brand voice.

🔌 i1n mcp

MCP server for AI coding assistants.

Starts a Model Context Protocol server that lets Cursor, Claude Code, Windsurf, and other AI assistants execute i1n commands directly from your IDE.

# Add to Claude Code
claude mcp add i1n -- npx i1n mcp

# Or add to .mcp.json / cursor config

{
  "mcpServers": {
    "i1n": {
      "command": "npx",
      "args": ["i1n", "mcp"]
    }
  }
}

8 tools available:

The killer workflow — tell your AI agent "internationalize this component":

1. The agent reads your file and identifies hardcoded strings

2. It calls i1n_extract_and_translate with the extracted strings

3. i1n pushes the keys, translates to all active languages, generates types

4. The agent rewrites your component with t('key') calls

A 60-minute task in 30 seconds.

📁 Supported Formats

🧩 SDK Usage

The i1n package includes a runtime SDK for web and mobile JS/TS projects. You can use it in two ways:

Standalone Mode — Replace your i18n library

Use the i1n native engine directly. No external dependencies needed.

import { init, t, setLocale } from "i1n";

// Load your translation resources
init({
  locale: "en_us",
  resources: {
    en_us: {
      auth: { login: "Login", title: "Welcome back, {user}" },
      items_one: "One item",
      items_other: "{count} items",
    },
    es_es: {
      auth: { login: "Entrar", title: "Bienvenido de nuevo, {user}" },
      items_one: "Un elemento",
      items_other: "{count} elementos",
    },
  },
});

// Autocomplete and type-safety work out of the box after 'i1n pull'
t("auth.login"); // "Login"

// Support for default values (useful during development)
t("new.key", { defaultValue: "Coming soon..." }); // "Coming soon..."

// Variables & Plurals
t("auth.title", { user: "Fran" }); // "Welcome back, Fran"
t("items", { count: 5 }); // "5 items"

// Switch language at runtime
setLocale("es_es");
t("auth.login"); // "Entrar"

Key resolution works with both nested and flat structures automatically — use whatever format your project prefers.

Bridge Mode — Keep your library, add type safety

Already using i18next, vue-i18n, or react-intl? Connect it to i1n with one line and get full autocompletion.

import i18next from "i18next";
import { registerI1n, t } from "i1n";

// Set up i18next as usual
await i18next.init({
  lng: "en",
  resources: {
    /* ... */
  },
});

// Connect to i1n — one line
registerI1n((key, params) => i18next.t(key, params));

// Now t() uses i18next under the hood, but with strict type checking
t("common.greeting", { name: "World" }); // Powered by i18next, typed by i1n

Works with any library:

• vue-i18n: registerI1n((key, params) => i18n.global.t(key, params))

• react-intl: registerI1n((key, params) => intl.formatMessage({ id: key }, params))

• Custom: registerI1n((key) => myLookup(key))

Pluralization

Define plural variants with _zero, _one, _other suffixes:

// In your translation files:
// "items_zero": "No items"
// "items_one": "One item"
// "items_other": "{count} items"

t("items", { count: 0 }); // "No items"
t("items", { count: 1 }); // "One item"
t("items", { count: 5 }); // "5 items"

Interpolation

Three syntaxes supported universally: {var}, {{var}}, %{var}

JavaScript (without TypeScript)

The SDK works in plain JS — you just don't get autocompletion:

import { init, t } from "i1n";
init({ locale: "en_us", resources: { en_us: { greeting: "Hello {name}" } } });
t("greeting", { name: "World" }); // "Hello World"

⚛️ React / Preact Integration

For a "plug and play" experience, use this minimalist provider pattern.

import { createContext, useContext, useState, useEffect } from "react";
import { init, t, getLocale, setLocale as sdkSetLocale } from "i1n";

// 1. Initialize with wordings
// (In a real app, you'd probably import these from your locales folder)
init({
  locale: "en_us",
  resources: {
    /* ... */
  },
});

const STORAGE_KEY = "i1n-locale";
const I1nContext = createContext({
  locale: "en_us",
  setLocale: (l: string) => {},
});

// 2. Persistent Provider
export function I1nProvider({ children, defaultLocale = "en_us" }) {
  const [locale, setLocaleState] = useState(() => {
    return localStorage.getItem(STORAGE_KEY) || defaultLocale;
  });

  // Keep SDK in sync
  useEffect(() => {
    sdkSetLocale(locale);
  }, [locale]);

  const setLocale = (newLocale: string) => {
    localStorage.setItem(STORAGE_KEY, newLocale);
    setLocaleState(newLocale);
  };

  return (
    <I1nContext.Provider value={{ locale, setLocale }}>
      {children}
    </I1nContext.Provider>
  );
}

// 3. Simple Hook
export const useI1n = () => ({ t, ...useContext(I1nContext) });

Usage:

const { t, setLocale } = useI1n();

return (
  <div>
    <h1>{t("auth.title", { user: "Fran" })}</h1>
    <button onClick={() => setLocale("es_es")}>Español</button>
  </div>
);

Non-JS Platforms

Flutter, Android, and iOS projects don't use the SDK. They use the translation files (.arb, .xml, .strings) generated by i1n pull with their native localization systems.

🛡️ Developer Experience

🔒 Privacy & Security

• Auto-Ignore: i1n init automatically adds sensitive config files to your .gitignore.

• Secret Management: API keys are only stored locally and never committed to version control.

• Encrypted Transmission: All sync operations happen over secure HTTPS channels.

🔒 Zero-Config Type Safety (TypeScript)

The CLI generates a lightweight declaration file (i1n.d.ts) that automatically augments the i1n package with your project's specific keys.

1. Pull: Run i1n pull. The CLI generates locales/i1n.d.ts and automatically updates your tsconfig.json so your IDE finds them immediately.

2. Usage: Import t from i1n and get full autocomplete + compile-time checking. No manual path mapping required.

import { t } from "i1n";

// Full autocomplete & compile-time checking
t("auth.login.title");

// ERROR: Argument of type '"auth.login.titlse"' is not assignable...
t("auth.login.titlse");

// Dynamic strings still pass through — useful for `t(item.name)`,
// runtime-built keys, etc.
declare const dynamicKey: string;
t(dynamicKey);

Strict literal checking landed in 1.3.0: passing a hard-coded string that isn't in I1nKeys is now a TypeScript error (no more silent [i1n] Missing translation warnings at runtime). Variables typed as string keep working without casts.

💳 Pricing

CLI, SDK, and MCP server are free on every plan. No credit card required for Starter.

Pro lifetime from $99 — only for the first 200 users.

📄 License

MIT — © 2026 i1n.ai