Translations (i18n)

The built-in Translations plugin manages the translation files of a project from a source: the reference language, saved in .atelier/i18n.json.

The source

The source can be:

• a file; the other languages are found next to it:
  • locales/fr.json, locales/en_US.json: one file per language in a folder;
  • locales/fr/common.json, locales/en/common.json: one folder per language;
  • messages.properties, messages_fr.properties: Java bundles (the file without suffix is the default language);
• the folder of a language (locales/fr): each file in it, subfolders included, is a namespace, and its keys are written namespace:key (common:menu.open, auth/login:title), as with i18next. The other languages are the sibling folders; a namespace a language does not have yet is created with the first value written;
• a regular expression on the paths of the project's files (relative, with /), with a (?<lang>…) group for the language and, optionally, (?<ns>…) for the namespace: src/i18n/messages\.(?<lang>\w+)\.json, app/(?<ns>\w+)/lang/(?<lang>[a-z]{2})\.json. You also give the reference language (English by default when it is there, otherwise the first one). Without ns, a language with several files tells them apart by their path.

JSON files can be flat ("menu.open") or nested ({"menu": {"open": …}}).

The Translations window

At the bottom. It first offers as source the files and folders that look like translations, the active file, or a regular expression. Then it shows every key in every language:

• missing in red;
• empty, or with other variables than the source ({name}, , %s, ${x}), in orange;
• identical to the source in grey;
• with the translated percentage of each language.

A click on a cell edits it and writes it to its file (in place, with the indentation of the file). You can add a language (a file created with every key of the source) or a key (in every language); the menu of a key opens it in the source or deletes it everywhere. The table follows the files changed outside the IDE.

For AI agents

The i18n MCP tool (see MCP server) gives the same to AI agents. action is:

Action	Result
languages	The languages
check	Every language compared to the source
check_language	One language in detail (with language)
add_language	Creates a language, with empty values or, with fill: "source", the text of the source

Results list the missing, extra, empty, different-variables and identical-to-source keys. source picks a source file or folder, pattern (with source_language) a regular expression.