Ares Cz MCP Server

@pipeworx/ares-cz

Czech business register (ARES) — look up any Czech company or sole trader by IČO or by name, from the Ministry of Finance's official register of economic subjects.

Part of Pipeworx — an MCP gateway connecting AI agents to 1863+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

• ares_lookup_ico({ ico }) — one economic subject by its 8-digit IČO: registered trading name, legal form, seat address, founding date, dissolution date, DIČ (VAT) number, CZ-NACE activity codes.
• ares_search_name({ name, limit, offset, onlyActive }) — subjects whose trading name matches, with the total match count so a precise hit is distinguishable from a common word.
• ares_vat_reliability({ id }) — is a Czech VAT payer flagged as unreliable (nespolehlivý plátce DPH)? Takes a DIČ (VAT number, CZ prefix optional) or an IČO. Returns an explicit status, the date the flag was published, the tax office code, the published bank accounts and the register's answer date.

Auth

Keyless. No registration, no header, no quota documented.

Data sources

• https://ares.gov.cz/ekonomicke-subjekty-v-be/rest/ekonomicke-subjekty/{ico} — one subject by IČO.

• https://ares.gov.cz/ekonomicke-subjekty-v-be/rest/ekonomicke-subjekty/vyhledat — POST search, returns pocetCelkem (total) plus a page of subjects.

• Czech Financial Administration (Finanční správa), register of unreliable VAT payers and published bank accounts — queried live per request, nothing copied. Reuse terms: public Czech state data, called as a client; no dataset is mirrored.

ARES is the Ministry of Finance's consolidated view over the commercial register (OR), the trade register (RŽP), the statistical register (RES) and the VAT payer register — so one IČO answers questions that would otherwise need three lookups.

Traps

• IČO must be zero-padded to 8 digits on the REST path. "177041" 404s, "00177041" resolves; the pack pads for you.
• A dissolved company still resolves. active is derived from whether datumZaniku is present, not from the lookup succeeding — treating a 200 as "still trading" is wrong.
• pocet (page size) caps at 200 and a larger value is a 400, so the pack clamps instead of passing through.
• Field names in raw stay Czech on purpose; the mapped fields are renamed to English so a caller does not need to know obchodniJmeno is the trading name.

VAT reliability: the three answers that must not be confused

• status: "unreliable" — flagged; unreliable_since is the publication date.
• status: "reliable" — a registered VAT payer that is NOT flagged.
• status: "not_a_vat_payer" — the number is not in the VAT payer register at all (not registered, deregistered, or wrong). Not a clean bill of health.
• A malformed id is an error, never a result: the register itself answers "not found" to garbage, so the pack validates first.
• Individuals (personal-number DIČ, not 8 digits) get status only; name, address and bank accounts are withheld.
• published_accounts is the list of accounts the payer registered for VAT; paying elsewhere can make the buyer liable for the VAT.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "ares-cz": {
      "url": "https://gateway.pipeworx.io/ares-cz/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/ares-cz/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1863+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/ares_lookup_ico \
  -H 'Content-Type: application/json' \
  -d '{"ico":"00177041"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/ares_lookup_ico. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Run it from npm

@pipeworx/mcp-ares-cz is a local stdio bridge to the Pipeworx gateway: your MCP client starts it with npx, and it forwards every call to the same https://gateway.pipeworx.io/ares-cz/mcp endpoint shown above. It needs network access; there is no offline mode.

{
  "mcpServers": {
    "ares-cz": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-ares-cz"]
    }
  }
}

Without a key it calls anonymously, capped at 50 calls a day. A free account raises that to 200 a day: get a key at https://pipeworx.io/signup and add "env": { "PIPEWORX_API_KEY": "<your key>" } to the server entry. The key is sent as a Bearer token, the same way a hosted connection sends it, so calls are metered and billed exactly as they are there.

It lists only this pack's tools by default. Set PIPEWORX_META_TOOLS=1 to also list ask_pipeworx and the other gateway-wide tools.

Behind an HTTPS proxy: Node's built-in fetch does not read HTTPS_PROXY by default. Newer Node releases honour it when NODE_USE_ENV_PROXY=1 is set; check your Node version's documentation.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Ares Cz data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT