LocaleSync: i18n Data Manager

A clean, sidebar-based control panel for managing your i18n translation files. Add new keys to every language file at once, create new language files in a click, spot missing translations at a glance, and translate them with a single click using GitHub Copilot or any other VS Code language model, all without leaving VS Code.

Features

• Sidebar control panel - a dedicated activity-bar view with everything you need.
• Configure once - point it at the folder where your *.json translation files live (per-workspace setting).
• One key, all languages - adding a new translation key writes to every language file in sync.
• Inline editing - click any key to expand and edit values for every language right in the sidebar. Saves on blur or Ctrl/Cmd+Enter.
• AI translation (optional) - one-click translate via the VS Code Language Model API. Works with GitHub Copilot or any other installed LM provider. Translate a single language or all of them from a chosen source.
• Translate from the editor - select any string in your code, right-click → i18n: Translate Selection…. The extension recognises both plain values and existing key paths (it tells you when a translation already exists), suggests sibling keys whose last segment matches, and lets you reuse a key or create a new one on the fly (with optional AI translation into every language). The selection is replaced with the key path itself by default (configurable via LocaleSynci18n.keyInsertTemplate).
• AI key naming from selection - select any free-form text, right-click → i18n: Create Translation Key from Selection (AI) and the model proposes a nicely-nested key path (e.g. "Fixed the card files uploads by removing the redundant webkit building" → fixes.redundantText), reusing your existing top-level groups when they fit. The key is created, translated into every language, and the selection is replaced with the configured template in one step.
• Auto-translate new languages - when adding a new language file, tick Auto-translate values with AI and every key is translated from your source language. Translation is batched (many keys per AI request) so even large files complete in seconds rather than minutes.
• Add languages in a click - new language files come pre-populated with all existing keys (empty, ready to translate).
• Sync check - find keys missing in some files and fill them in (with empty values) in one click.
• Smart search - filter by key name or by the value text in any language.
• Incomplete-only filter - instantly see what still needs translating.
• Nested keys supported - dot-notation in the UI (common.buttons.submit), nested JSON on disk.
• Theme-aware - uses VS Code's theme variables, so it matches whatever you've got.

📸 Preview

Getting started

1. Install the extension from the VS Code Marketplace.
2. Open a workspace that contains your translation files.
3. Click the 🌐 i18n Data Manager icon in the activity bar.
4. Click Choose Translations Folder and pick the folder containing your en.json, fr.json, etc.
5. Done, start adding keys and languages from the sidebar.

AI translation

If you have GitHub Copilot (or any other VS Code language model provider) installed and signed in, expand any translation key and you'll see two new actions:

• ✨ next to each language translate just that language. You'll be prompted to pick which other language to translate from (the source). The model receives the source value and writes the translation directly into the target language's file.
• ✨ Translate all in the key's actions row translate the same key into every other language at once. You pick the source language; if any target already has a value, you're asked whether to overwrite or only fill empties.
• Translate Selection from the editor - select a string OR an existing key path, right-click and choose i18n: Translate Selection…. The extension:
  • Tells you when the selection is already a key in your translations and previews each language's value.
  • Lists keys whose value matches the selection (so you can reuse them).
  • Lists keys whose last segment matches the selection's last segment (e.g. selecting accessCategoryTypeNameHeader surfaces every key ending in .accessCategoryTypeNameHeader).
  • Otherwise lets you create a new key (the new key input is pre-filled with the selection when it looks like a path; otherwise the source value input is pre-filled). Optionally translates the new key into every other language.
  • Replaces the selection according to the LocaleSynci18n.keyInsertTemplate setting (default ${key} — just the key path; set it to something like t('${key}') if your codebase needs a wrapper).
• Auto-translate when creating a new language file - the Add Language dialog includes an Auto-translate values with AI checkbox (shown when a model is available). When checked, every value is translated from the chosen source language right after the file is created. Translation is batched (many keys per AI request) so even large dictionaries finish in seconds rather than minutes; if a batch reply can't be parsed, the affected entries fall back to per-key translation automatically.

Notes:

• The extension uses the VS Code Language Model API. Your prompts go to whichever provider you have installed, Anthropic isn't called directly, no API key is shipped, and the user (you) authorizes usage on first run.
• The buttons only appear when a model is reachable. If you don't have an LM provider, the extension works exactly as before, no buttons, no errors.
• Placeholders ({name}, {{count}}, %s, %d, ICU plurals, HTML tags) are preserved by the prompt. Always review machine translations before shipping, especially for shorter keys where context can be ambiguous.
• You can disable the AI buttons entirely via the LocaleSynci18n.aiTranslate.enabled setting, even when a model is available.

Expected file layout

The extension expects one JSON file per language inside the configured folder. The filename (without .json) is taken as the language code:

locales/
├── en.json
├── fr.json
├── es.json
└── de-DE.json

Both flat ({ "hello": "Hi" }) and nested ({ "common": { "hello": "Hi" } }) JSON are supported. Nested files are flattened to dot-notation in the UI and re-nested on write, preserving your existing structure.

Keyboard shortcuts (inside the sidebar)

Settings

These settings are written to your workspace settings, so each project can have its own config.

Commands

Available from the Command Palette (Ctrl/Cmd+Shift+P) and the editor context menu:

• i18n Data Manager: Configure Translations Folder
• i18n Data Manager: Refresh
• i18n: Translate Selection… - also available by right-clicking a selection in any text editor.
• i18n: Create Translation Key from Selection (AI) - also available by right-clicking a selection. Asks AI for a nicely-nested key path, creates the key with the selection as its source value, and translates it to every other language.

Build from source

git clone https://github.com/mmlTools/localesync-i18n.git
cd localesync-i18n
npm install
npm run compile

Then open the folder in VS Code and press F5 to launch the Extension Development Host.

See CONTRIBUTING.md for the full dev workflow.

Package & publish

npm install -g @vscode/vsce
npm run package        # → localesync-i18n-1.1.0.vsix
npm run publish        # publishes to the marketplace (requires `vsce login`)

Requirements

• VS Code 1.90.0 or later (required for the Language Model API).
• For AI translation: any installed VS Code language model provider for example, GitHub Copilot. The rest of the extension has no extra dependencies.

Known limitations

• Only .json files are supported (not .yaml, .po, .properties, etc.).
• Pluralization rules (CLDR plural categories) aren't handled, values are treated as plain strings.
• Comments in JSON files aren't preserved (standard JSON.parse / JSON.stringify).
• AI translation quality depends on the underlying language model and the amount of context in the source string. Always review output for short or ambiguous keys.

Changelog

See CHANGELOG.md for the full version history.

License

MIT © StreamRsc.com