About firmproof
firmproof is a local bridge to Fuentio's hosted MCP server for checking companies against official registers in France, Spain, and the UK. It provides sourced identity, sanctions, insolvency, and change information for company and supplier reviews.
Key features
- 01Look up companies by official ID or name
- 02Verify company identity with an audit proof code
- 03Screen sanctions and check insolvency
- 04Validate registered addresses and VAT numbers
- 05Track register changes and company groups
Use cases
- 01Verify a customer or supplier during onboarding
- 02Screen a company for sanctions or insolvency
- 03Review registered addresses and VAT details
- 04Compare company records and track changes
MCP support
firmproof exposes company-register lookup and verification tools to MCP clients and forwards calls to Fuentio's hosted MCP server.
Configuration
Local server config is the same for every client. Copy it into your client’s MCP config file.
Tools
19Saved tool list · updated 1w ago
| Parameter | Type | Required | Description |
|---|---|---|---|
| detail | enum | No | summary: a few key fields; standard (default): the record, long lists shortened; full: everything.summary | standard | full |
| format | enum | No | Answer format: json (default); csv, tsv, markdown, html (table), xml or ndjson come back inline, one row per company with source and fetched_at; xlsx or parquet as a download link valid 24 hours. Same units; search takes limit (up to 100 rows) with a non-json format.json | csv | tsv | xlsx | markdown | html | xml | ndjson | parquet |
| country | enum | Yes | ISO country code: FR or ES or GB.FR | ES | GB |
| id_scheme | any | No | Optional: force the ID type when it is ambiguous. |
| identifier | string | Yes | Official ID. FR: SIREN (9 digits), SIRET (14) or VAT (FR + 11). ES: Registro Mercantil sheet, e.g. VI-23266. GB: Companies House company number, e.g. 00445790. |
Details
From the project READMEfirmproof
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,ESorGB),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(normalordetailed).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: passrowsorbatch_id.list_coverage— the countries, ID formats and official sources covered. Takes no arguments.
Configuration
FUENTIO_MCP_URL(optional) — override the upstream endpoint. Defaults tohttps://api.fuentio.com/mcp. (The override hook is this rebuild's own labelled reconstruction.)FUENTIO_API_KEY(optional) — when set, every upstream request carries anX-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. NoAuthorizationheader 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.
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