i1n 💎

Localization as code. The modern architecture to localize apps at the speed of thought.

i1n bridges the gap between Developers, AI Agents, and Product Teams, making localization a native part of your development workflow rather than a chore.

🏛️ The i1n Philosophy

i1n is built on three core pillars designed to make localization extremely fast, efficient, and low-maintenance:

🚀 Dev-First

Zero-friction integration with your existing codebase. i1n lives in your terminal and your IDE, providing native type-safety and automated workflows that eliminate manual JSON editing.

🤖 AI-Native

Built for the age of AI. i1n provides smart orchestration and context rules that turn your AI agents (Cursor, Claude, Copilot, etc.) into localization experts who understand your project's specific conventions and tone.

⚡ Team-Sync

A seamless bridge between Developers, AI Agents, and Product Teams. Localize features as you build them, with zero maintenance overhead and real-time synchronization.

📦 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. Sync local wordings to the cloud
i1n push

# 3. Pull translations & get zero-config 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.

• Uses WU (Wording Units) efficiently with a robust caching layer.

⬇️ 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 wording/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"]
    }
  }
}

7 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");

💳 Credits & Billing

i1n uses Wording Units (WU) for fair billing:

• AI Translation: 1.0 WU per item.

• Smart Cache: Only 0.01–0.2 WU per hit.

• Refills: Credits refill automatically based on your plan cycle.

📄 License

MIT — © 2026 i1n.ai