# ICU MessageFormat Validator Alternative MCP for AI Agents MCP

> ICU MessageFormat Validator Alternative prevents broken internationalization strings by catching syntax errors before they hit production. It identifies unmatched braces, unescaped quotes, and incorrect plural categories in your translation templates to ensure your interpolation logic stays intact across all languages.

## Overview
- **Category:** developer-tools
- **Price:** Free
- **Endpoint:** https://edge.vinkius.com/vk_preview_IaQlGvSL4zMDdiFv0D4FuL8L3jDEnXfQZ1I61OIc/mcp
- **Tags:** icu, messageformat, internationalization, translation, syntax-validator

## Description

Managing translation strings is a nightmare when a single missing brace breaks the entire UI. You spend hours debugging why a name isn't appearing or why a sentence just cuts off mid-way. This Connector acts as a gatekeeper for your ICU MessageFormat templates. Instead of manually scanning every curly bracket, you can hand your strings to your agent and let it find the structural flaws. It looks deep into the logic of plural and select blocks to make sure your categories are valid and that the mandatory 'other' category isn't missing. You can also pull out a clean list of every variable used in a template so you know exactly what data your backend needs to provide. When you connect this to your workflow through Vinkius, you stop treating localization as a guessing game and start treating it like a verifiable part of your build process.

## Tools

### validate_category_logic
Checks that your plural and select blocks use valid categories like 'one' or 'other'. It ensures you never miss a required fallback category.

### extract_template_variables
Scans your message strings to find every unique variable name used. This gives you an instant list of all necessary interpolation parameters.

### validate_structural_braces
Inspects the string for unmatched curly braces or broken quote escaping. It prevents structural errors from corrupting your translation engine.

## Prompt Examples

**Prompt:** 
```
Is this string okay? '{count, plural, one {# item} other {# items}}'
```

**Response:** 
```
The string is valid. The structure and categories are correct.
```

**Prompt:** 
```
What variables do I need for this message: 'Hello {user}, welcome to {city}!'
```

**Response:** 
```
| Variable |
| :--- |
| `user` |
| `city` |
```

**Prompt:** 
```
Check this string for errors: '{name, select, male {Mr. {name}} female {Ms. {name}} }'
```

**Response:** 
```
Found an error: The `select` block is missing the required **'other'** category.
```

## Capabilities

### Catch broken translation strings
Detects when a curly bracket is left open or closed incorrectly.

### Audit pluralization logic
Ensures all categories like 'one' or 'many' are correctly defined in your blocks.

### Inventory template variables
Lists every dynamic parameter used in your message strings automatically.

### Spot unescaped quotes
Finds single quotes that would break the interpolation engine.

## Use Cases

### Fixing broken pluralization
A developer pushes a change that breaks pluralization; they ask their agent to check the new string using validate_category_logic.

### Mapping required data keys
An engineer needs to know which keys to add to a JSON file; they use extract_template_variables to get the list.

### Auditing large translation batches
A localization lead is worried about broken quotes in a large batch of strings; they run validate_structural_braces on the set.

## Benefits

- Prevent UI crashes by catching unmatched brackets early.
- Ensure complete pluralization coverage for all languages.
- Speed up backend integration by mapping required data automatically.
- Avoid broken interpolation by finding unescaped quotes.
- Maintain high translation quality without manual syntax audits.

## How It Works

The bottom line is you stop shipping broken translations.

1. Connect your preferred AI client to the Connector via Vinkius.
2. Paste or provide your ICU MessageFormat strings to your agent.
3. Receive a detailed breakdown of any syntax errors or variable requirements.

## Frequently Asked Questions

**How can I use ICU MessageFormat Validator Alternative to check my translations?**
You provide your ICU strings to your AI client, and it will analyze them for syntax errors or missing categories.

**Does ICU MessageFormat Validator Alternative catch unmatched braces?**
Yes, it specifically looks for any opening or closing curly brackets that do not have a matching pair.

**Can I find all variables in a message using ICU MessageFormat Validator Alternative?**
Absolutely. You can ask your agent to list every dynamic parameter used within a specific template string.

**Will ICU MessageFormat Validator Alternative help with pluralization errors?**
It checks that all categories like 'one', 'few', and 'many' are correctly defined and that the 'other' category is present.

**Is ICU MessageFormat Validator Alternative compatible with Claude or Cursor?**
Yes, it works with any MCP-compatible client including Claude, Cursor, and Windsurf.

**How does the validator handle single quotes?**
The `validate_structural_braces` tool implements a state machine to track escaping. It recognizes that two consecutive single quotes (double-single-quote) represent a literal single quote, preventing the parser from incorrectly terminating an escaped sequence.

**What happens if I use an invalid category in a plural block?**
If you include an unsupported keyword like 'none' or 'all', the `validate_category_logic` tool will flag a syntax error, identifying the exact character offset where the invalid category was detected.

**Can I use this to find all variables in my translation files?**
Yes, by using the `extract_template_variables` tool, you can provide any ICU string and receive a complete list of all unique variable names found within the template, such as 'userName' or 'itemCount'.