skanfirmy.pl — MCP server

A free, stateless MCP (Model Context Protocol) server that lets AI agentsverify Polish companies and validate EU VAT numbers directly from officialgovernment registers — no key, no registration, no limits beyond the sourceregistries' own.

Endpoint: https://skanfirmy.pl/mcp (JSON-RPC 2.0 over Streamable HTTP)
9 tools combining the VAT Register (Ministry of Finance), KRS (Ministry ofJustice), REGON (Statistics Poland / GUS) and VIES (European Commission).
Also usable as plain REST for crawlers/agents that can't speak MCP.

Made by Bartosz Kuć — the same person behindskanfirmy.pl and theotwarteAPI.pl catalog of Polish & EU public APIs.

Tools

Tool	What it does
`sprawdz_nip`	VAT status (Biała Lista) + KRS data for a company by NIP
`sprawdz_lista_nip`	Bulk lookup of up to 30 NIPs in one call (MF VAT Register)
`sprawdz_regon`	REGON registry data (GUS) by NIP — incl. sole traders not in KRS
`sprawdz_vies`	Validate an EU VAT number via VIES (European Commission)
`sprawdz_rachunek`	Is a bank account on the VAT White List for a given NIP
`generuj_mikrorachunek`	Individual tax micro-account (PIT/CIT/VAT) from NIP/PESEL
`szukaj_pkd`	Search the PKD 2025 business-activity classification
`oblicz_odsetki`	Statutory / commercial (B2B) late-payment interest calculator
`szukaj_katalog_api`	Search otwarteAPI.pl — a catalog of other public PL/EU APIs

Connect

Any MCP client that supports remote (Streamable HTTP) servers — point it at:

https://skanfirmy.pl/mcp

Claude Desktop / stdio-only clients — bridge with mcp-remote:

{
  "mcpServers": {
    "skanfirmy": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://skanfirmy.pl/mcp"]
    }
  }
}

Raw JSON-RPC (no MCP client needed):

# list tools
curl -s https://skanfirmy.pl/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

# check a company by NIP
curl -s https://skanfirmy.pl/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"sprawdz_nip","arguments":{"nip":"5261040828"}}}'

Plain REST (no MCP)

For agents/crawlers that just want a URL:

GET https://skanfirmy.pl/nip/{nip} — VAT + KRS
GET https://skanfirmy.pl/nips/{comma,separated,nips} — bulk (≤30)
GET https://skanfirmy.pl/regon/{nip} — REGON registry data
GET https://skanfirmy.pl/vies/{country}/{number} — EU VAT (VIES)

Add ?format=json for JSON. Full docs: skanfirmy.pl/llms.txt.

Data sources

VAT Register / Biała Lista (Ministry of Finance), KRS (Ministry of Justice),REGON / BIR (Statistics Poland — GUS), VIES (European Commission). Independentproject — not affiliated with any of them. Nothing is persisted; responses aretransiently CDN-cached (max 24h), POST /mcp isn't cached at all.

Author

Bartosz Kuć· skanfirmy.pl· github.com/bartosz-kuc· linkedin.com/in/bartosz-kuc· cal.com/bartosz-kuc

License

MIT © Bartosz Kuć. This repository documents the hostedserver and holds its MCP registry manifest; the server itself runs athttps://skanfirmy.pl/mcp.

skanfirmy.pl — MCP server