firmproof

firmproof is a small local bridge to Fuentio's hosted MCP server, which checks companies against the official registers of France, Spain and the United Kingdom. Give it an official ID — a French SIREN, a Spanish Registro Mercantil sheet, a UK Companies House number — and it can read the register record, verify the company for onboarding, screen it against sanctions lists, check insolvency and address and VAT, and follow what changed over time, each answer carrying its official source.

The bridge keeps no register data of its own. It serves the upstream server's tool list locally, exactly as captured from the live endpoint, and forwards each tool call upstream, returning the result untouched.

Tools

• lookup_company — one company by official ID: status, address, legal form, activity, source and check date. Required: country (FR, ES or GB), identifier.

• search_companies — find companies by name, 10 per page, each with a match score. Required: query, country.

• get_company_history — versions of a company's record with the fields that changed and their sources. Required: country, identifier.

• verify_company — a registry verification with an outcome, reasons, checks, warning signals and a proof code for an auditor. Required: country, identifier.

• get_receipt — the receipt of an earlier verification by its proof code. Required: proof_code, format (normal or detailed).

• resolve_company — decide whether a record you hold is a company in the registers, with evidence and candidate decisions. Required: country.

• explain_match — why two register records are, or are not, the same company. Required: left, right.

• what_changed — what changed at a company since a date. Required: entity_id, since.

• screen_company — screen a company's names against sanctions lists. Required: country, identifier.

• check_insolvency — insolvency notices and state from BODACC and BORME. Required: country, identifier.

• check_address — validate a registered address against the official address base. Required: country, identifier.

• get_graph — a company's group: GLEIF parents and subsidiaries. Required: entity_id.

• report_issue — report a wrong or missing answer for re-checking against the official source. Required: subject, category, message.

• get_evidence — the evidence behind a company's facts, field by field with sources. Required: entity_id.

• check_vat — a company's EU VAT number and how it was obtained (registration itself is never checked). Required: country, identifier.

• watch_company — register your own https endpoint to be notified when a company's records change. Required: entity_id, callback_url.

• review_report — one review-ready report combining identity, facts, a year of changes and every check. Required: country, identifier.

• check_supplier_list — check 2 to 100 suppliers at once, or read a batch you started. No required fields: pass rows or batch_id.

• list_coverage — the countries, ID formats and official sources covered. Takes no arguments.

Related MCP server: Prometiam Company Data

Configuration

• FUENTIO_MCP_URL (optional) — override the upstream endpoint. Defaults to https://api.fuentio.com/mcp. (The override hook is this rebuild's own labelled reconstruction.)

• FUENTIO_API_KEY (optional) — when set, every upstream request carries an X-API-Key: <key> header. Some upstream tools require a key, and a free key is obtainable from the vendor. When it is not set, no key header is sent. No Authorization header is ever sent. (This forwarding is also a labelled reconstruction; the original surface was captured keyless.)

Forwarding mechanics

On the first tool call the client opens a streamable HTTP session with the upstream: a JSON-RPC initialize request (protocolVersion 2025-03-26, clientInfo name firmproof), then a notifications/initialized notification, then the tools/call request carrying the caller's arguments unchanged. When the upstream answers initialize with an Mcp-Session-Id header, that value rides on every later request of the session, which is reused for the life of the process. Replies may arrive as plain JSON or as server-sent events; both are read.

Successful upstream results pass through verbatim, including any isError flag the upstream sets. Failures — a JSON-RPC error, a non-2xx status, an unreadable response, or a request that cannot be completed — come back as an isError result whose text starts with firmproof error: (this rendering is this rebuild's own labelled reconstruction).

CLI

Each tool is also a subcommand taking one JSON argument string (omit it for tools that take none):

npx @reneturcios/firmproof lookup_company '{"country":"FR","identifier":"441639465"}'
npx @reneturcios/firmproof search_companies '{"country":"FR","query":"renault"}'
npx @reneturcios/firmproof verify_company '{"country":"GB","identifier":"00445790"}'
npx @reneturcios/firmproof list_coverage
npx @reneturcios/firmproof --version

Exit codes: 0 on success, 1 on an isError result, 2 on a usage error.

MCP server

npx -y @reneturcios/firmproof mcp

MCP client config:

{
  "mcpServers": {
    "firmproof": {
      "command": "npx",
      "args": ["-y", "@reneturcios/firmproof", "mcp"]
    }
  }
}

Docker

docker run -i ghcr.io/cloudcorprecords/firmproof
docker run --rm ghcr.io/cloudcorprecords/firmproof --version

The container's default command is mcp, so the first form is a stdio MCP server; any other arguments reach the CLI normally.

Development

npm install
npm run build
npm test
npm run dev

The test suite runs entirely against a stubbed JSON-RPC upstream — no live network calls.

License

MIT — see LICENSE.