ares — Claude Code MCP server: Czech and Slovak company registry
Connects your agent to the official ARES registry: company lookup by IČO, name, address and CZ-NACE, plus VAT payer checks.
claude mcp add --transport http ares https://ares.cz-agents.dev/mcpWhat ares does
This server wraps the public ARES API run by the Czech Ministry of Finance. Records come straight from the source. Ten tools cover different jobs: lookup_by_ico pulls one company's card from a 7- or 8-digit IČO with its address, legal form, DIČ and trade activities; search_companies matches on name with filters for city, street, PSČ and CZ-NACE; search_by_address lists every entity at one Czech street address, which is how you check a virtual office.
Finance and officer lookups have their own calls. get_bank_accounts returns transparent accounts published in ARES, get_statutaries names the active statutory-body members, get_owners lists owners with their reported shares and removal dates, check_vat_payer confirms VAT registration, and validate_dic checks the format and checksum of a Czech DIČ. get_history surfaces former names and address changes. One caveat: get_owners reflects only what was filed in the public register, so an empty akcionáři result for an a.s. is expected rather than a failure. Judging the statutory unreliable-payer flag is a job for ADIS — ARES does not do it.
Two ways to run it. The hosted endpoint https://ares.cz-agents.dev/mcp speaks HTTP and is rate-limited per IP. The local route starts with npx -y @czagents/ares and needs no keys. Source is MIT-licensed, with build steps in martinhavel/cz-agents-mcp.
What it helps with
- look up a company by IČO and pull its official details
- confirm whether a counterparty is VAT registered
- count how many firms share one address
- build a sector list from a CZ-NACE code
- find the current members of a statutory body
Example prompts for the agent
- Look up the ARES record for IČO 26168685 and show its address and legal form
- Check in ARES whether IČO 26168685 is a VAT payer
- List the companies registered at Radlická, Praha, PSČ 15000
How to install ares
1Platform CLI: remote server
claude mcp add --transport http ares https://ares.cz-agents.dev/mcp2Platform CLI
claude mcp add ares -- npx -y @czagents/ares1Platform CLI: remote server
codex mcp add ares --url https://ares.cz-agents.dev/mcp2Platform CLI
codex mcp add ares -- npx -y @czagents/aresConfig file
{
"mcpServers": {
"ares": {
"url": "https://ares.cz-agents.dev/mcp"
}
}
}{
"mcpServers": {
"ares": {
"command": "npx",
"args": [
"-y",
"@czagents/ares"
]
}
}
}Config file
{
"servers": {
"ares": {
"type": "http",
"url": "https://ares.cz-agents.dev/mcp"
}
}
}{
"servers": {
"ares": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@czagents/ares"
]
}
}
}1Platform CLI: remote server
gemini mcp add -t http ares https://ares.cz-agents.dev/mcp2Platform CLI
gemini mcp add ares npx -y @czagents/aresStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about ares
How do I install ares in Claude Code?
Over HTTP: claude mcp add --transport http ares https://ares.cz-agents.dev/mcp. Or locally: claude mcp add ares -- npx -y @czagents/ares.
What does ares do?
It gives your agent access to the official ARES registry: company lookup by IČO, name, address and CZ-NACE, plus VAT status, bank accounts, statutaries and owners.
How is the hosted endpoint different from the local one?
The hosted endpoint https://ares.cz-agents.dev/mcp caps requests per IP. Running locally with npx -y @czagents/ares has no such cap.
