Official Model Context Protocol (MCP) server for vatnode — lets AI
agents (Claude Desktop, Cursor, ChatGPT, Cline, Continue, …) validate
EU VAT numbers and look up VAT rates from any MCP-compatible client.

Extracted from the vatnode product monorepo into this public repo so:
- the source is open and verifiable (important — users hand their API
  key to this code)
- releases can use npm Trusted Publishing instead of long-lived NPM_TOKEN
- the community can file issues and contribute fixes

Five tools:
- get_country_vat_rates, list_eu_vat_rates, check_vat_format,
  list_supported_countries — free, offline via eu-vat-rates-data
- validate_vat_number — live VIES via api.vatnode.dev (requires API key)

13-case stdio smoke test exercises every tool with good and bad input.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>