@autoglot/next

Automatic i18n translation for Next.js. Wraps your Next.js config so translations run after every production build — no manual step required.

Works with both webpack and Turbopack.

Quick start

npm install @autoglot/next

// next.config.mjs
import { withAutoglot } from '@autoglot/next';

export default withAutoglot({
  source: 'src/locales/en.json',
  lang: ['es', 'fr', 'de'],
})({
  // your existing next config
});

Set your API key:

export AUTOGLOT_API_KEY=your_key_here

Run next build and translations appear alongside your source file.

Setup

1. Sign up at autoglot.app
2. Go to dashboard / API keys and create a key
3. Add AUTOGLOT_API_KEY to your environment (.env.local, CI secrets, etc.)
4. Install the packages:

npm install @autoglot/next

Configuration

withAutoglot(options) takes an options object and returns a function that wraps your Next.js config.

Options

Option	Type	Required	Default	Description
source	string	Yes		Path to source translation file (e.g. src/locales/en.json)
lang	string[]	Yes		Target language codes
sourceLanguage	string	No	Auto-detect from filename	Source language code
apiKey	string	No	AUTOGLOT_API_KEY env var	API key
apiUrl	string	No	https://api.autoglot.app	API base URL
project	string	No		Project for glossary/style guide (owner/repo format)
skipCache	boolean	No	false	Skip translation cache

Output

Translated files are written next to the source file. For example, given source: "src/locales/en.json" and lang: ["es", "fr"], you'll get:

src/locales/
  en.json       ← your source (untouched)
  es.json       ← generated
  fr.json       ← generated

Examples

Basic i18next setup

// next.config.mjs
import { withAutoglot } from '@autoglot/next';

export default withAutoglot({
  source: 'public/locales/en/common.json',
  lang: ['es', 'fr', 'de', 'ja'],
})({});

With existing Next.js config

// next.config.mjs
import { withAutoglot } from '@autoglot/next';

const nextConfig = {
  reactStrictMode: true,
  images: { domains: ['example.com'] },
};

export default withAutoglot({
  source: 'src/locales/en.json',
  lang: ['es', 'fr'],
})(nextConfig);

Composing with other plugins

// next.config.mjs
import { withAutoglot } from '@autoglot/next';
import createMDX from '@next/mdx';

const withMDX = createMDX();

export default withAutoglot({
  source: 'src/locales/en.json',
  lang: ['es', 'fr', 'de'],
})(withMDX({
  pageExtensions: ['js', 'jsx', 'mdx', 'ts', 'tsx'],
}));

Link to a project (glossary + style guide)

export default withAutoglot({
  source: 'src/locales/en.json',
  lang: ['es', 'fr', 'de'],
  project: 'acme/my-app',
})({});

Explicit source language

export default withAutoglot({
  source: 'locales/messages.json',
  lang: ['fr', 'de'],
  sourceLanguage: 'en',
})({});

Skip cache for fresh translations

export default withAutoglot({
  source: 'src/locales/en.json',
  lang: ['es'],
  skipCache: true,
})({});

Only in production builds

Translations only run during next build, not next dev. The plugin hooks into the production compilation lifecycle, so no extra configuration is needed.

How it works

1. Next.js 15.4.1+ — uses the built-in compiler.runAfterProductionCompile hook, which works with both webpack and Turbopack
2. Older versions — falls back to a webpack plugin that runs on the done hook (after compilation completes)
3. If both mechanisms are available, a deduplication guard ensures translation only runs once

The plugin reads your source file, sends it to the autoglot API, polls until translation completes, and writes the translated files to disk.

Supported file formats

Format	Extension
JSON	.json
YAML	.yml, .yaml
PO/POT	.po, .pot
Xcode String Catalog	.xcstrings

Supported languages

Code	Language	Code	Language
de	German	ja	Japanese
fr	French	ko	Korean
es	Spanish	zh-Hans	Simplified Chinese
it	Italian	zh-Hant	Traditional Chinese
pt	Portuguese	ar	Arabic
pt-BR	Brazilian Portuguese	he	Hebrew
nl	Dutch	hi	Hindi
pl	Polish	th	Thai
ru	Russian	vi	Vietnamese
uk	Ukrainian	id	Indonesian
tr	Turkish	ms	Malay
sv	Swedish	cs	Czech
da	Danish	hu	Hungarian
fi	Finnish	ro	Romanian
nb	Norwegian	sk	Slovak
el	Greek	bg	Bulgarian

Links

• autoglot dashboard
• Get API key
• @autoglot/cli — standalone CLI and library
• Report issues