Localis

Localis is a local tool for managing software translations. It runs on the user's machine and points at a project on disk. It finds keys that other locales are missing, translates only those keys with AI, and writes them back into the user's own files after approval. It computes missing translations from files each time it opens, with no database to drift out of sync. It detects the i18n library, translation directories, source language, and locales from manifests, config, and source rather than folder names alone. It works with JSON, YAML, CSV, and ARB layouts, and reads and writes JSON, YAML, and CSV. Detection covers next-intl, next-i18next, next-international, react-i18next, i18next, Lingui, Paraglide, Tolgee, and plain JSON setups. Existing translations are never touched; only absent or blank keys are sent to the model or written. Placeholders are compared between source and translation, and a mismatch blocks approval. File shape is preserved, including nesting, key order, indentation, trailing newline, YAML comments, and CSV delimiter and extra columns. Nothing leaves the machine: no account, no database, no repository upload, and the only outbound request is to the configured provider. A small CLI provides localis status --check, which exits non-zero when translations lag so CI can hold the line.