i18n

name: i18n description: > Handle internationalization (i18n) translation files and produce culturally authentic translations. Use when: (1) editing, creating, or modifying translation files (JSON, YAML, TypeScript, JS) — especially large ones that risk exceeding token limits; (2) translating UI strings into any supported language/dialect; (3) reviewing translations for cultural accuracy and naturalness; (4) syncing translation keys across multiple locale files; (5) adding new languages or regional variants to an existing i18n setup. Triggers on "translate", "i18n", "localization", "translation file", "locale", "add language", "translation keys", or any specific locale code (e.g., th, ja, ko, zh-CN, de, fr, es, it, zh-TW, zh-HK, th-bupphe). Does NOT trigger on defining or glossing a single word/phrase inside a sentence ("what does X mean here", "define X in context") — that is the define skill. This skill is for i18n files and shipping localized strings, not inline word-meaning lookups. metadata: tier: draft

i18n — Translation Files & Cultural Rewriting

This skill has two parts:

1. File Handling — How to safely edit translation files without hitting token limits.
2. Translation Teams — How to produce culturally authentic translations using a multi-role review process.

Part 1: Handling Translation / i18n Files

Why This Matters

Translation files can be extremely large (thousands of keys). Attempting to rewrite an entire translation file will likely exceed output token limits and cause errors. Always use surgical, minimal edits instead.

File Formats

Translation files may exist in any of these formats:

Rules

1. NEVER rewrite an existing translation file in full

• Do NOT output the full file content when editing an existing file.
• Do NOT use a "replace entire file" operation to change a few keys.
• If a tool only supports full-file writes (no partial edit), use the script approach (see below).

Exceptions — full-file writes are fine when:

• Creating a new locale file from scratch (e.g., adding it.json for the first time).
• Generating an initial translation of an entire file into a new language.
• The file is small enough (< 200 keys) that a full rewrite won't risk token limits.

The rule exists to prevent token-limit blowups on large existing files, not to block legitimate file creation.

2. Prefer surgical edits

When adding, updating, or removing keys, target only the affected lines.

Example — adding keys to a JSON file:

   "dashboard.title": "Dashboard",
+  "dashboard.subtitle": "Welcome back",
+  "dashboard.empty_state": "No data available",
   "dashboard.footer": "© 2025"

Example — adding keys to a TypeScript file:

 export const en = {
   dashboard: {
     title: 'Dashboard',
+    subtitle: 'Welcome back',
+    emptyState: 'No data available',
     footer: '© 2025',
   },
 } as const;

3. Use a script for bulk operations

When changes are too numerous or complex for surgical edits (e.g., adding 50+ keys, restructuring namespaces, syncing across locales), write a one-off script that reads, transforms, and writes the file programmatically.

For JSON files:

import fs from 'fs';

const filePath = './locales/en.json';
const translations = JSON.parse(fs.readFileSync(filePath, 'utf-8'));

const newKeys = {
  'feature.title': 'New Feature',
  'feature.description': 'This is a new feature',
};

Object.assign(translations, newKeys);
fs.writeFileSync(filePath, JSON.stringify(translations, null, 2) + '\n');

For TypeScript files:

TS translation files cannot be naively JSON-parsed. Use one of these strategies:

• Strategy A — Dynamic import (preferred when structure is export default or named export):

  const mod = await import('./locales/en.ts');
  const translations = mod.default ?? mod.en;
  // Merge new keys, then serialize back
  

  ⚠️ This loses as const / satisfies type annotations. You must re-apply them when writing back. See serialization note below.

• Strategy B — AST manipulation (when type safety must be preserved exactly):

  Use ts-morph or similar to add properties to the exported object without altering the rest of the file.

  import { Project, SyntaxKind } from 'ts-morph';
  
  const project = new Project();
  const sourceFile = project.addSourceFileAtPath('./locales/en.ts');
  const obj = sourceFile
    .getVariableDeclarationOrThrow('en')
    .getInitializerIfKindOrThrow(SyntaxKind.ObjectLiteralExpression);
  
  obj.addPropertyAssignment({
    name: "'newKey'",
    initializer: "'New Value'",
  });
  
  await sourceFile.save();
  

• Strategy C — Regex/text insertion (simple cases only):

  Find the closing } of the target object and insert before it. Fragile but acceptable for appending a few keys to a well-known structure.

Serialization note for TS files:

When writing back a TS translation file, preserve the original structure:

// If the original uses `as const`:
const output = `export const en = ${JSON.stringify(merged, null, 2)} as const;\n`;

// If the original uses `satisfies`:
const output = `export const en = ${JSON.stringify(merged, null, 2)} satisfies Translations;\n`;

Ensure the import statement for the type (e.g., Translations) is preserved.

4. When syncing across locales

If the task is "add these keys to all locale files":

1. Define the new keys in a single object/variable.
2. Write a script that iterates over all locale files.
3. For each file, read → merge (without overwriting existing keys) → write.
4. Log which files were updated and which keys were added.

Do NOT manually edit each locale file one by one — this is error-prone and token-expensive.

5. Validate after changes

After any translation file modification:

• Verify the file is valid (parseable JSON, valid TS syntax, etc.).
• Run any existing i18n linting or type-checking commands if available.
• Confirm no existing keys were accidentally removed or overwritten.

Part 2: Translation Teams — Role-Based Contextual Rewriting

Philosophy

Translation is not word-for-word substitution. It is contextual rewriting inside cultural reality. Every string a user reads should feel like it was originally written in their language — by someone who lives in their market, uses their apps, and thinks in their idioms.

To achieve this, adopt a multi-role review process before finalizing any translation. Each role contributes a different lens. Internally simulate all applicable roles and reconcile their perspectives before producing final output.

Workflow

1. Identify the target locale — language alone isn't enough. Thai (standard) ≠ Thai (Gen Z) ≠ Thai Isan. Each has its own team.
2. Draft an initial translation considering UI context, intent, and tone.
3. Pass the draft through each role's lens for the target locale.
4. Handle pluralization — apply the target language's pluralization rules (see Pluralization section below).
5. Reconcile conflicting feedback (e.g., copywriter wants flair, UX reviewer wants brevity) with a bias toward clarity and cultural fit.
6. Output the final translation. Add a brief note if a key required non-obvious cultural adaptation.

Shared Roles (All Languages)

These roles apply to every target locale:

• @ux localization reviewer — Ensures translations work within UI constraints (character length, button labels, truncation). Validates that tone matches the interaction context (error message vs. celebration vs. onboarding).

• @i18n engineer — Handles interpolation variables ({count}, {name}), pluralization rules, gender agreement, and format consistency (dates, numbers, currency). Ensures the translated string won't break at runtime.

Per-locale teams, pluralization & cultural notes

The per-locale translation teams, pluralization rules, counter-word rules, and all cultural notes live in a shared reference: references/locale-knowledge.md.

This is the shared cultural engine for two skills — i18n (this one: translation-file production) and define (inline contextual definition/translation). When working a specific locale, load it: it carries the per-locale role tables, register systems, dialect vocabulary, classical forms (e.g. th-bupphe), honorifics, classifiers, the pluralization category table, and the zh-CN → zh-TW "not a character swap" rule.

Edit locale facts there once; both skills inherit. This skill layers its file-handling discipline (Part 1) and its @ux localization reviewer / @i18n engineer roles on top; define layers its own comprehension lenses (lexicographer, etymology, register) for learner-facing glosses.