What does this MCP actually validate?

It validates the structural integrity of braces, the escaping of quotes, the logic of plural/select blocks, and the presence of template variables in ICU MessageFormat strings.

How do I use this with Claude or Cursor?

You connect to the Vinkius-hosted MCP once. After that, your agent in Claude, Cursor, or any other compatible client can call the capabilities directly.

Can it find missing 'other' categories in plural blocks?

Yes. The validate_category_logic capability specifically checks that all required categories, including the mandatory 'other' category, are present.

Does it help with variable management?

Yes. You can use the extract_template_variables capability to get a complete list of all unique variables used in a message.

Is the validation deterministic?

Yes. The MCP uses a deterministic finite automaton to ensure consistent and reliable syntax analysis.

How does the validator handle single quotes?

The validate_structural_braces capability 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 capability 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 capability, 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'.

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Connect ICU MessageFormat Validator to ChatGPT and Claude

Set it up once and it works in ChatGPT, Claude, Cursor, and any other client you love. It all runs safely in the background, so you can relax and focus on what really matters. Catch syntax errors before they break your internationalization logic.

Ask AI about this Connector

Developed, maintained, and hosted by Vinkius.

MCP VERIFIED · PRODUCTION READY · VINKIUS GUARANTEED

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Works with modern AI clients that support MCP, including ChatGPT, Claude, Cursor, and more.

Your AI does the work. We keep it safe and sound.

No other AI tool gives you this. Your workflow runs in the client you already love, your account stays protected, and you decide what the agent can and cannot do. It is the whole reason to make the switch.

Each Connector lives inside our infrastructure, the same place where your workflow runs. The three things below are already part of it, working quietly in the background so you never have to think about them. Nothing to add, nothing to set up, nothing to worry about.

V8 Isolate01

Each Connector runs inside its own sealed environment.

Each Connector runs inside its own sealed V8 runtime — no access to your files, your system, or other servers. A Connector never sees past its own request.

Kill Switch02

One switch stops every agent. Instantly.

One action deactivates every Connector, revokes every token, and ends every session at once. AI Governance keeps the record.

FinOps per User03

Spending limits that pause instead of surprise.

Every user keeps their own connections and credentials, isolated from everyone else. Anything that would cross your spending limit is held for your approval, not billed.

Three controls, built into the layer your AI connects through.

Curated set · 3 capabilities

We ship only the actions that matter.

Capability set01 / 01

01-03

3 capabilities in this set.

Part of 3 available through ICU MessageFormat Validator.

01
Validate structural braces
This capability checks the structural integrity of your ICU messages. It tracks brace depth and quote escaping to find unmatched characters that break interpolation.
02
Extract template variables
This capability parses your ICU strings to find all unique variable names. It gives you a clean list of every parameter required by the template.
03
Validate category logic
This capability verifies the logic inside plural and select blocks. It ensures all identifiers belong to the correct set of categories and that the mandatory 'other' category exists.

Real work

What teams actually run

Pre-deployment Syntax Audits

Run your entire translation library through the agent to catch broken strings before they hit production.

Variable Mapping

Use the agent to identify exactly which data points need to be passed to a specific ICU template.

Pluralization Debugging

Verify that complex plural and select rules are logically sound and follow ICU standards.

Real-time Template Authoring

Have your agent check your work as you write new internationalized strings in your IDE.

One connector, every AI

ICU MessageFormat Validator works with the most popular AI clients.

These are the most popular clients, each with a step-by-step guide: one link, set up once, with governance and visibility built in. And because everything runs on the MCP standard, the same connection also works in any other compatible client — nothing to rebuild.

Building your own app? The connector is yours to use.

You don't need a client to put ICU MessageFormat Validator to work: the same hosted connection plugs into your own applications and agent code, with the same governance on every request. Build with it, chat with it — one connection for both.

Observed, not estimated

604ms average. Fast in production.

ICU MessageFormat Validator is checked daily against the live service.

Daily averagePeak 735ms

Oct 3Today

Fastest day: 502ms
Slowest day: 735ms
14-day trend: Improving-11%

Connect your client

One URL. Every client.

Activate the Connector, copy your link, and paste it into the client you already use. 3 capabilities arrive ready to run.

Preview access · not provider authentication

The vk_preview_* token belongs to Vinkius preview infrastructure. It lets Claude discover and display the capabilities of ICU MessageFormat Validator, so you can see the experience inside your AI.

It does not authenticate your account with ICU MessageFormat Validator. Actions requiring credentials or live account data may not run until you activate the Connector and authorize the service.

ICU MessageFormat Validator Connector

You're all set. Choose your MCP client and follow the setup instructions.

Connector linkhttps://edge.vinkius.com/vk_preview_IaQlGvSL4zMDdiFv0D4FuL8L3jDEnXfQZ1I61OIc/mcp

Claude Desktop

Follow the steps below to connect in seconds.

1In Claude Desktop, open Settings → Connectors.
2Click “Add custom connector” and paste the connector link above as the remote MCP server URL.
3Click Add and start a new chat — ICU MessageFormat Validator capabilities are ready to use.

Configuration · claude_desktop_config.jsonCopy

{
  "mcpServers": {
    "icu-messageformat-validator-mcp": {
      "url": "https://edge.vinkius.com/vk_preview_IaQlGvSL4zMDdiFv0D4FuL8L3jDEnXfQZ1I61OIc/mcp"
    }
  }
}

Claude
ChatGPT
Cursor
VS Code
Windsurf
Claude Code
JetBrains
Cline

Step-by-step instructions for each client are in the guide. How to connect

Guided setup for Claude? Set up ICU MessageFormat Validator in Claude and other AIs

See all the AI clients this connector works with ↑

Who it's for

Built for the work ICU MessageFormat Validator owners hand off.

This MCP is built for developers and localization engineers managing complex internationalization workflows.

01
Localization Engineers
They hand off complex translation strings to the agent to ensure they won't break the UI.
02
Frontend Developers
They use the agent to verify that the variables in their code match the requirements of the ICU templates.
03
Software Architects
They use the capability to audit the structural integrity of large-scale i18n implementation files.

FAQ

Questions ICU MessageFormat Validator owners ask.

01
What does this MCP actually validate?
It validates the structural integrity of braces, the escaping of quotes, the logic of plural/select blocks, and the presence of template variables in ICU MessageFormat strings.
02
How do I use this with Claude or Cursor?
You connect to the Vinkius-hosted MCP once. After that, your agent in Claude, Cursor, or any other compatible client can call the capabilities directly.
03
Can it find missing 'other' categories in plural blocks?
Yes. The validate_category_logic capability specifically checks that all required categories, including the mandatory 'other' category, are present.
04
Does it help with variable management?
Yes. You can use the extract_template_variables capability to get a complete list of all unique variables used in a message.
05
Is the validation deterministic?
Yes. The MCP uses a deterministic finite automaton to ensure consistent and reliable syntax analysis.
06
How does the validator handle single quotes?
The validate_structural_braces capability 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.
07
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 capability will flag a syntax error, identifying the exact character offset where the invalid category was detected.
08
Can I use this to find all variables in my translation files?
Yes, by using the extract_template_variables capability, 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'.

Explore

More in Developer Tools

Connect ICU MessageFormat Validator to Claude, Cursor, ChatGPT & more

Your AI does the work. We keep it safe and sound.

Each Connector runs inside its own sealed environment.

One switch stops every agent. Instantly.

Spending limits that pause instead of surprise.

We ship only the actions that matter.

01-03

Validate structural braces

Extract template variables

Validate category logic

What teams actually run

Pre-deployment Syntax Audits

Variable Mapping

Pluralization Debugging

Real-time Template Authoring

Building your own app? The connector is yours to use.

ICU MessageFormat Validator Connector

Claude Desktop

Localization Engineers

Frontend Developers

Software Architects

What does this MCP actually validate?

How do I use this with Claude or Cursor?

Can it find missing 'other' categories in plural blocks?

Does it help with variable management?

Is the validation deterministic?

How does the validator handle single quotes?

What happens if I use an invalid category in a plural block?

Can I use this to find all variables in my translation files?

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