String Catalog

An MCP server for working with Xcode String Catalog (.xcstrings) files. It lets AI assistants read, search, and update your iOS/macOS localization strings.

Installation

Claude Code

claude mcp add string-catalog-mcp -- npx string-catalog-mcp

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Available Tools

list_supported_languages

List all languages in a string catalog with the source language identified.

"What languages are supported in my Localizable.xcstrings file?"

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get_catalog_statistics

Get translation coverage breakdown per language, including total keys and completion percentages.

"Show me the translation statistics for my string catalog"

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get_translations_for_key

Get all translations for a specific key across all supported languages.

"Show me all translations for the 'welcome_message' key"

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search_keys

Search for localization keys containing a specific substring (case-insensitive).

"Find all keys that contain 'error' in my string catalog"

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list_all_keys

List all localization keys in the catalog (supports pagination for large catalogs).

"List all the localization keys in my project"

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update_translations

Add or update translations in the string catalog. Accepts a structured JSON payload with support for iOS format placeholders (%@, %d, %lld, %f, %1$@).

"Add German and French translations for the 'hello_world' key"

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Available Prompts

translate-strings

Generate translations for specific keys with guidance on format placeholders.

"Use the translate-strings prompt to translate 'welcome_message' and 'goodbye' into German, French, and Japanese"

batch-translate

Translate all untranslated or stale strings in a catalog for specified languages.

"Use batch-translate to add German translations for all missing strings in my catalog"

review-translations

Review existing translations for quality, consistency, and proper placeholder usage.

"Review my German translations for quality issues"

Common Workflows

Add a new language to your app

1. "What languages are supported in my Localizable.xcstrings?"
2. "Use batch-translate to add Spanish translations to /path/to/Localizable.xcstrings"

Translate specific strings

1. "Search for keys containing 'settings' in my string catalog"
2. "Show me translations for the 'settings_title' key"
3. "Translate 'settings_title' and 'settings_description' into German and French"

Review translation quality

1. "Show me translation statistics for my catalog"
2. "Review German translations for placeholder issues and consistency"

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License

MIT