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Check French and Spanish Companies Inside Claude

Add Fuentio to Claude as a custom connector, or to Claude Code in one command, then ask about French and Spanish companies: answers with sources and dates.

· By the Fuentio team · 5 min read

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You are in a conversation with Claude, reviewing a supplier, and you need to know whether a French company is still active or which Spanish company sits behind a name on an invoice. Instead of switching to three government websites, you can ask Claude directly, and it answers from the official registers, with the source and the date it checked.

What you'll learn

  • How to add Fuentio to claude.ai and Claude Desktop
  • How to add it to Claude Code, with or without a key
  • Which questions to ask, and what the answers look like

Short answer: in claude.ai or Claude Desktop, add a custom connector with the URL https://api.fuentio.com/mcp. In Claude Code, run claude mcp add --transport http fuentio https://api.fuentio.com/mcp. No key is needed to start; a free key adds 100 units a month.

Add Fuentio to claude.ai or Claude Desktop

  1. Open Settings → Connectors.
  2. Choose Add custom connector.
  3. Name: Fuentio. URL: https://api.fuentio.com/mcp.
  4. Click Add.
  5. In a chat, open the tools menu and turn on Fuentio.

That's it. Custom connectors can't send an API key, so they use the keyless trial: 20 units a day, enough for a lookup or two, a search and a verification. If you need more, use Claude Code with a key (below) or call the REST API from your own tools.

Add Fuentio to Claude Code

One command, no key needed to start:

claude mcp add --transport http fuentio https://api.fuentio.com/mcp

With a free or paid key, pass it as a header:

claude mcp add --transport http fuentio https://api.fuentio.com/mcp \
  --header "Authorization: Bearer YOUR_API_KEY"

Claude Code then lists Fuentio's tools and calls them when your question needs company data. The tools that need a key (sanctions screening of a company's own names, the review report, watching a company, the company group, reporting an issue) work as soon as the key is set.

What to ask

Plain questions work. A few that map well to the tools:

  • “Is SIREN 552032534 still active? Give sources.” Claude calls lookup_company and quotes the status, its date and the official source.
  • “Verify this supplier for onboarding: SIREN 552100554.” Claude calls verify_company and reports the outcome, the reasons and the proof code.
  • “Find Spanish companies named Telefónica in the BORME.” Claude calls search_companies with country ES, since Spain has no tax-number lookup.
  • “Any insolvency notices for SIREN 552100554?” Claude calls check_insolvency and says what was covered.
  • “Is the customer in my CRM, ACME at 92100, the same company as in the register?” Claude calls resolve_company, which only links on an official number.

Each tool's description tells Claude when to use it and when not to, so you rarely need to name a tool yourself.

What the answers look like

On 12 October 2026, the live server answered a verification of Danone like this:

DANONE (FR, SIREN 552032534): verified, active per Annuaire des Entreprises (API Recherche d'entreprises), checked 2026-10-12. Proof FUE-FR-20261012-ABAT38.

and a verification of Peugeot SA, a company that no longer trades, like this:

PEUGEOT SA (FR, SIREN 552100554): unverified, inactive per Annuaire des Entreprises (API Recherche d'entreprises), checked 2026-10-12. Proof FUE-FR-20261012-YK5YXJ.

Claude can quote either line as it is. The outcome, the source, the date and a proof code are all there, so the answer can go into a review note without rewriting. The walkthrough in supplier onboarding in France and Spain in one call shows the full answer behind each line.

When Fuentio can't answer, Claude sees why. Ask it to look up a Spanish NIF and the server replies that tax-number lookup isn't supported and suggests searching by name. Text fields copied from the registers come with an instruction to treat them as data, never as instructions, so a company name can't steer the conversation.

Other clients

The same URL works in any MCP client that supports streamable HTTP: Cursor, VS Code, ChatGPT in developer mode and others. The docs have the setup for each, and where to find Fuentio lists the registries and marketplaces where it is published.

Units and keys

  • Without a key: 20 units a day.
  • Free key: 100 units a month, one per person, no card.
  • A lookup costs 1 unit, a search 2, a verification 5. Errors cost nothing, except a well-formed number that isn't found.

Create your free key on the pricing page, then add it to Claude Code with the header above.

Limits

  • France and Spain only.
  • No data about people: no person's name appears in any answer.
  • No Spanish NIF or CIF lookup: search by name, then use the registry sheet.
  • Spanish records cover companies with a BORME act since 2009; their status is “unknown” unless an act says otherwise.
  • No annual accounts.

See what we cover in France and Spain. For what Fuentio is and where its data comes from, read Fuentio is live. Questions: hello@fuentio.com.

Frequently asked questions

Does the custom connector need a key?

No. Custom connectors use the keyless trial, 20 units a day.

Can I use my own key in claude.ai?

Custom connectors can't send a key today. Use Claude Code with the --header option, or call the REST API.

Which tools need a key?

Sanctions screening of a company's own names, the review report, watching a company, the company group and reporting an issue.

Does Claude see people's names?

No. Fuentio serves no person's name in any answer.

Sources

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