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verbaly

verbaly

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github.com/AronSotoDeveloper Tools4Updated today

About verbaly

Verbaly is an i18n compiler and runtime for application teams that write text in code and need typed translations and CI checks. It extracts messages, generates keys, and provides an MCP server for agent-assisted translation drafts that require human approval.

Key features

  1. 01Extract messages and generate stable keys
  2. 02Infer typed parameters from message text
  3. 03Check missing or broken translations in CI
  4. 04Export catalogs for translation workflows
  5. 05Review drafts in a local panel

Use cases

  1. 01Add translations while developing application text
  2. 02Catch missing parameters or plural cases before release
  3. 03Prepare translation drafts with an agent
  4. 04Review and approve drafts in Studio

MCP support

The @verbaly/mcp server exposes the translation workflow as tools and provides resources for project configuration and catalogs. Agents can create drafts, but approval remains a human action.

Configuration

Local server config is the same for every client. Copy it into your client’s MCP config file.

mcp.json · Universal config
{
"mcpServers": {
"aronsoto-verbaly": {
"command": "npx",
"args": [
"-y",
"@verbaly/mcp"
]
}
}
}
Run commandnpx -y @verbaly/mcp

Local servers need a runtime on your machine (e.g. Node.js 18+). Config file locations differ by client; see your client’s docs.

Packages
npm@verbaly/mcp0.79.0

Tools

9

Saved tool list · updated today

ParameterTypeRequiredDescription
dirstringNoDirectory for the catalogs (default: locales)
rootstringNoProject root holding verbaly.config (defaults to the server working directory)
localesarrayNoEvery locale, source included
sourceLocalestringNoThe language you write in (default: en)

Details

From the project README

Verbaly

Write your text in the code. Ship it in every language.

An i18n compiler and a tiny runtime for React, Vue, Svelte, Next.js, Nuxt, SvelteKit, Astro and plain HTML.
No key files to keep in sync, params typed from the text, and a CI gate that stops broken translations.

npm version CI coverage Socket supply chain security OpenSSF Scorecard published with npm provenance 3.35KB gzip runtime zero runtime dependencies TypeScript MIT

On the left, a component that writes t`Welcome back, ${name}`, t`You have ${count} new messages` and t`Open inbox`. On the right, the same page in a browser switching from English to Spanish to Portuguese. Below, the four steps: write, extract, translate, check.

React Next.js Vue Nuxt Svelte and SvelteKit Astro Vite webpack, Rollup, esbuild and Rspack Plain HTML, no framework

The idea

Most i18n tools ask you to invent a key for every sentence, write it in a file per language and keep the files in step with the code by hand. Verbaly turns that around:

// with key files: name it, write it in en.json, es.json, pt.json, keep them in sync
t('dashboard.welcome_back', { name });

// with Verbaly: write the sentence where it is used
t`Welcome back, ${name}`;

// and the compiler writes a stable key and a typed call for you
t('ESsQIvlA', { name });

The runtime that ships is 3.35 KB gzip with zero dependencies, measured on every release by a gate in this repo (pnpm --filter verbaly size).

Quick start

pnpm add verbaly @verbaly/vite
pnpm add -D @verbaly/compiler   # the verbaly command: init, extract, check
npx verbaly init
// vite.config.ts
import verbaly from '@verbaly/vite';

export default { plugins: [verbaly()] };
// anywhere in your app: extracted and typed on save
import { t, setLocale } from 'verbaly/app';

t`Hello ${name}`;
await setLocale('es'); // loads only the Spanish module

verbaly/app is your project's own module: the plugin writes it from your config, with your languages and catalogs already in it. Next.js, Nuxt, SvelteKit and Astro have their own one-line setup: pick yours in the row above, or read the full docs at https://verbaly-web.vercel.app/docs.

Why Verbaly

✍️ No key files
You write the sentence. The compiler names it and keeps every language file in step with your code.
🧷 Typed from the text
{name}, plurals, currency and dates come from the message itself, so a wrong or missing param fails to compile.
🛑 Broken ones never ship
verbaly check catches a missing translation, and one that lost a {param}, a tag or a plural case, in plain words.
🪶 Small and fast
Zero dependencies, one module per language, and a hot path benchmarked against i18next on every release.
🔄 Any workflow
Plain JSON, XLIFF, CSV and gettext PO for translators, Android and iOS exports, and AI drafts a person approves.
🤖 Agent ready
An MCP server, an Agent Skill and llms.txt, with drafts an agent can write but never approve.

Review translations in a panel

npx verbaly-studio

Verbaly Studio: an overview that says five things are waiting, one translation that breaks the site, two missing messages and two machine translations nobody has read, with the languages and the last commits to the catalogs

Studio serves your project over localhost: what is missing, what is broken, what a machine wrote and where each text lives in your code. Your JSON files are the database and git is the history, a save runs the same validations as verbaly check, and it never edits your source text.

How it compares

Verbalyi18nextLinguiParaglidetypesafe-i18n
Type-safe keys & params✅ inferred from textplugin/manualpartial✅✅
Runtime size (gzip)3.35KB, zero deps13.6KB (19.0 +react)2.2KB (3.3 +react)compiled1.2KB
Setup1 Vite pluginheavy configmacros + Babel/SWCinlang projectgenerator
Key maintenancenone, extractedby handextract → compile stepby handby hand
Dynamic / CMS content✅ real runtime path✅✅⚠️ weak✅
Plain HTML (no framework)✅ DOM interpreter❌❌❌❌
Missing-translation gate✅ fails CI onlyruntime warningCI step✅❌
Broken-translation gate✅ fails CI only❌❌❌❌
Catalog formatplain JSONJSONPO/JSONinlang formatTS files

Sizes are min+gzip of each library's main entry with React external, measured with the same method on 2026-10-15.

Coding agents

claude mcp add verbaly -- npx -y @verbaly/mcp

The MCP server gives your agent the whole cycle as tools, with structured output and resources to read your config and catalogs. Machine translations stay drafts until a person approves them (verbaly review --approve, or Studio): approving is deliberately not a tool. The Agent Skill teaches the write, extract, check and translate cycle (npx degit AronSoto/verbaly/skills/verbaly .claude/skills/verbaly), and the docs publish llms.txt.

Packages

PackageWhat it is
verbalyThe runtime: t, Intl formats, locale helpers and the DOM interpreter
@verbaly/compilerExtraction, typed codegen, the gate and the verbaly command
@verbaly/vite · @verbaly/unpluginBundler plugins: Vite, and webpack, Rollup, esbuild and Rspack
@verbaly/react · @verbaly/vue · @verbaly/svelteFramework adapters: hooks or composables plus <Trans>
@verbaly/next · @verbaly/nuxt · @verbaly/sveltekitServer rendering: the language per request, hydration with no flash
@verbaly/astroAstro integration: .astro extraction and a static build per language
@verbaly/mcpMCP server: the translation cycle as tools for an agent
@verbaly/studioThe local review panel above

All of them share one version number, and every release is published from CI with npm provenance.

Editor: see the text behind a key on hover

Generated keys are hashes, so t('a1B2c3D4') in a diff tells you nothing. The i18n-ally extension shows the real text inline once you point it at your catalogs. Two files, no Verbaly config changes:

.vscode/settings.json

{
  "i18n-ally.localesPaths": ["locales"],
  "i18n-ally.keystyle": "flat",
  "i18n-ally.sourceLanguage": "en",
  "i18n-ally.displayLanguage": "en"
}

.vscode/i18n-ally-custom-framework.yml

languageIds:
  - javascript
  - typescript
  - javascriptreact
  - typescriptreact
  - vue
  - svelte
  - astro
usageMatchRegex:
  - "[^\\w\\d]t\\(\\s*['\"`]({key})['\"`]"
monopoly: true

keystyle has to match your catalogs: flat for dotted keys, nested for groups. Use the extension for reading, not writing: its extract and rename actions assume you own the keys, and here the compiler does.

Development

pnpm install
pnpm build      # tsdown: ESM + CJS + .d.ts
pnpm test       # each package's suite
pnpm typecheck
pnpm --filter verbaly bench   # the hot path against i18next

Verbaly is 0.x: the API can still change between minor versions, and every change is in the changelog. Contributions are welcome: see CONTRIBUTING.md.

Feedback

  • Something broke or surprised you: open a bug. A minimal snippet is enough.
  • Something felt like friction: tell us what. The roadmap follows real use.
  • It just works: a star or a mention helps others find it.

Sponsor

Verbaly is MIT-licensed, dependency-free and built independently. If it saves you time, sponsoring it funds the road to 1.0: more integrations, faster releases and long-term maintenance.

Sponsor Verbaly on GitHub

License

MIT © Aron Soto · @AronSoto

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