langsync: zsh

One source file. Every language in sync.

Name: LangSync
Author: Nevil

Fills missing keys, re-translates edited ones and keeps ICU plurals intact.

% curl -sSL langsync.nevil.dev | bash

View on GitHub

nevil@macbook ~ % langsync --features

Features

Only what changed: A snapshot of every source string tells new keys from edited ones. Translations you did not touch stay as they are.
ICU plurals stay valid: Only the words inside plural and select branches go to the translator. Each rebuilt message is parsed before it is written.
Repairs broken strings: A target with broken ICU, often left by an older tool, is re-translated in place on the next run.
Batched and parallel: Keys go out in batches and locales run side by side. When the API pushes back, it slows down and retries.
Placeholders untouched: {name}, <b> tags and the brand names you whitelist come back exactly as they went in.
Errors with the fix: Every error and warning ends with the command that fixes it, ready to paste.

nevil@macbook ~ % open screenshots/

Screenshots

langsync output: a settings summary, a table showing de, es and fr all done, and Translated: 32, Failed: 0 — First run: 32 keys across three locales, from one English file.

jq showing the French and German cart strings with the ICU plural structure, one and other branches and the # placeholder unchanged — The words change. `{count, plural, one {#…}}` does not.

langsync --check reporting drift: one missing and one changed key per locale, exit code 1 — `--check` exits 1 when a locale drifts, so CI catches it.

Two errors, a missing locale folder and a missing source file, each followed by a How to fix box with the exact command — Wrong path? It prints the `mkdir` or the `ls` you need.

nevil@macbook ~ % langsync --install

Install

# macOS and Linux, via pipx
curl -sSL langsync.nevil.dev | bash

# or by hand, anywhere Python 3 runs
pipx install git+https://github.com/dracu-lah/langsync-cli.git

Point it at your source

# langsync.json, in your project root
{ "source": "messages/en.json", "dir": "messages" }

Run it

langsync                 # sync every locale in dir
langsync --dry-run       # show what would change
langsync -l fr,de        # only these locales
langsync --prune         # drop keys the source removed
langsync --check         # exit 1 on drift, for CI

Add an empty {} file per language, like messages/fr.json, and LangSync fills it. The README covers every flag and config key.

nevil@macbook ~ % langsync --support

Free, MIT licensed, made by one person.

If it saves you an afternoon of copy and paste, a sponsor or a coffee keeps it going.

Buy me a coffee Star the repo

nevil@macbook ~ %