VAT Validation MCP Server

# Changelog All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html). ## [1.0.1] - 2025-07-16 ### Fixed - **Critical Bug Fix**: Fixed VIES API response schema validation error - Changed schema field from `isValid` to `valid` to match actual VIES REST API response format - Updated client code to use correct field name (`validatedData.valid` instead of `validatedData.isValid`) - Fixed unit tests to use correct mock data format - Resolves validation errors when checking Slovak VAT numbers (e.g., SK7020000130) - All EU VAT number validations now work correctly without Zod validation errors ### Technical Changes - Updated `vatValidationResponseSchema` in `src/schemas.ts` - Updated `checkVatNumber` and `checkVatTestService` methods in `src/client.ts` - Updated test mock data in `src/__tests__/client.test.ts` - All tests now pass successfully ## [1.0.0] - 2024-01-15 ### Added - Initial release of VIES VAT Checker MCP Server - `check_vat_number` tool for real VAT number validation - `check_vat_test_service` tool for testing service integration - `check_vies_status` tool for checking service availability - `list_eu_member_states` tool for listing supported countries - Comprehensive error handling with bilingual messages (Slovak/English) - Support for all 27 EU member states - TypeScript implementation with strict type checking - Unit tests with Jest - Docker support with multi-stage builds - Complete documentation and examples - Configuration examples for Claude Desktop and Augment ### Features - Real-time VAT number validation using official VIES REST API - Automatic VAT number preprocessing and correction - Service status monitoring for all EU member states - Bilingual support (Slovak and English) - Comprehensive input validation using Zod schemas - Production-ready error handling and logging - ESM (ES Modules) support - Full TypeScript type safety ### Technical Details - Built with @modelcontextprotocol/sdk v0.4.0 - Uses axios for HTTP requests with proper error handling - Zod for runtime type validation - Jest for testing with ESM support - ESLint for code quality - Docker containerization support - Comprehensive CI/CD ready structure