registry-mcp — the company registry MCP

The company registry MCP — a company registry for AI agents, as an MCP server and REST API over national business registries, any country.

Countries: Norway (brreg), United Kingdom (Companies House).

Norway — brreg / Brønnøysundregistrene / Enhetsregisteret. Look up a company by organisasjonsnummer (orgnr, org.nr), search by name, check MVA / VAT registration, and compute statutory filing deadlines. Also published as brreg-mcp, an alias package that installs exactly this server.

United Kingdom — Companies House. Look up a company by company number (company registration number, CRN), search by name, and read the annual accounts and confirmation statement deadlines the register publishes. The country code is GB, not UK. Companies House requires a free API key — see Configuration.

Status: 0.2.0. The five tools and their response shapes are frozen; the hosted API at api.foretak.dev is live, and listed in the official MCP registry as io.github.foretak/registry-mcp.

Add to Claude Code

claude mcp add registry-mcp --transport http https://api.foretak.dev/mcp

Or run it locally over stdio, no install step:

claude mcp add registry-mcp -- uvx registry-mcp

What it returns

$ curl https://api.foretak.dev/v1/NO/company/923609016
{
  "country": "NO", "registry": "brreg",
  "id": "923609016", "id_formatted": "923 609 016", "id_scheme": "organisasjonsnummer",
  "name": "EQUINOR ASA",
  "legal_form_code": "ASA", "legal_form": "Public limited company", "legal_form_local": "Allmennaksjeselskap",
  "status": "active", "is_active": true, "registered_at": "1995-03-12",
  "vat_registered": true, "vat_number": "NO923609016MVA", "vat_registered_at": "1989-07-01",
  "employees": 21239, "share_capital": 5976872600.0, "share_capital_currency": "NOK",
  "business_address": {"lines": ["Forusbeen 50"], "postal_code": "4035", "city": "STAVANGER"},
  "source": "Enhetsregisteret (Brønnøysundregistrene)", "license": "NLOD 2.0"
}

Abridged — the full CompanyReport also carries previous_names, industry_codes, registers, purpose, parent_id, confidence, cached, fetched_at and notes. Every field is documented in llms-full.txt §5.

The United Kingdom, same shape, same abridgement:

$ curl https://api.foretak.dev/v1/GB/company/00445790
{
  "country": "GB", "registry": "companies-house",
  "id": "00445790", "id_formatted": null, "id_scheme": "company number",
  "name": "TESCO PLC",
  "legal_form_code": "plc", "legal_form": "Public limited company",
  "status": "active", "is_active": true, "registered_at": "1947-11-27",
  "vat_registered": null, "vat_number": null,
  "employees": null, "employees_reported": false,
  "registers": {"charges": false, "insolvency": false},
  "industry_codes": [{"code": "47110", "description": null, "scheme": "SIC 2007", "rank": 1}],
  "business_address": {"lines": ["Tesco House, Shire Park", "Kestrel Way"], "postal_code": "AL7 1GA", "city": "Welwyn Garden City"},
  "published_deadlines": [
    {"kind": "annual_accounts", "due_date": "2027-08-26", "period_end": "2027-02-26", "overdue": false, "source": "accounts.next_accounts.due_on"},
    {"kind": "confirmation_statement", "due_date": "2027-07-02", "period_end": "2027-06-18", "overdue": false, "source": "confirmation_statement.next_due"}
  ],
  "source": "Companies House (UK)", "license": "Crown copyright — Companies House public register, free to re-use"
}

published_deadlines carries the dates the register publishes itself, with the upstream field each came from. It is [] for Norway, which computes all of its own.

Note the nulls. Companies House publishes no VAT status, no employee count and no share capital for any company, so those fields are null rather than guessed — null means "this register does not say", never "no". That honesty is the point of one shape across countries.

And the deadlines, which is where the UK module earns its keep:

$ curl "https://api.foretak.dev/v1/GB/company/00445790/deadlines?today=2026-09-04"
{
  "company_name": "TESCO PLC", "today": "2026-09-04",
  "deadlines": [
    {"kind": "confirmation_statement", "local_name": "Confirmation statement (CS01)",
     "due_date": "2027-07-02", "period_end": "2027-06-18", "days_until": 301,
     "applies_because": "Companies House publishes this date for the company itself; it is the register's own figure, not a calculation."},
    {"kind": "annual_accounts", "local_name": "Annual accounts",
     "due_date": "2027-08-26", "period_end": "2027-02-26", "days_until": 356,
     "applies_because": "Companies House publishes this date for the company itself; it is the register's own figure, not a calculation."}
  ]
}

Where Companies House publishes a date, it is quoted; where it does not, the date is computed from a cited statute and applies_because says so. UK deadlines never roll forward off a weekend or bank holiday, and days_until goes negative for a filing the register still shows as overdue.

Tools

Plus the resource registry://rules/{country} (identifier rules, legal forms, deadline rules — read once instead of validating in a loop) and the prompt explain_company.

Configuration

{
  "mcpServers": {
    "registry-mcp": {
      "command": "uvx",
      "args": ["registry-mcp"],
      "env": {
        "REGISTRY_MCP_CONTACT_EMAIL": "you@example.com",
        "COMPANIES_HOUSE_API_KEY": "your-companies-house-key"
      }
    }
  }
}

{
  "mcpServers": {
    "registry-mcp": {
      "command": "uvx",
      "args": ["registry-mcp"],
      "env": { "REGISTRY_MCP_CONTACT_EMAIL": "you@example.com" }
    }
  }
}

{
  "mcpServers": {
    "registry-mcp": {
      "command": "uvx",
      "args": ["registry-mcp"],
      "env": { "REGISTRY_MCP_CONTACT_EMAIL": "you@example.com" }
    }
  }
}

{
  "mcpServers": {
    "registry-mcp": { "command": "npx", "args": ["-y", "registry-mcp"] }
  }
}

{
  "mcpServers": {
    "registry-mcp": { "type": "http", "url": "https://api.foretak.dev/mcp" }
  }
}

Environment variables — all optional:

REST

Every tool has a REST twin returning the identical JSON document.

# One company by organisasjonsnummer
curl https://api.foretak.dev/v1/NO/company/923609016

# Search by name
curl "https://api.foretak.dev/v1/NO/search?q=equinor&limit=5"

# Statutory filing deadlines, from a date you choose
curl "https://api.foretak.dev/v1/NO/company/923609016/deadlines?today=2026-01-15"

# Checksum-validate an identifier — no upstream call, instant
curl https://api.foretak.dev/v1/NO/validate/923609016

# Which countries are live, and which need an API key
curl https://api.foretak.dev/v1/countries

# The same five routes for the United Kingdom — GB, never UK
curl https://api.foretak.dev/v1/GB/company/00445790
curl "https://api.foretak.dev/v1/GB/search?q=tesco&limit=5"
curl "https://api.foretak.dev/v1/GB/company/00445790/deadlines?today=2026-09-04"
curl https://api.foretak.dev/v1/GB/validate/445790

Machine-readable docs: /llms.txt, /llms-full.txt, /openapi.json.

Adding your country

Norway is one folder. So is the United Kingdom: registries/gb/ was added as four files and one import line, and GB appeared in list_countries, in every tool, in /openapi.json and in registry://rules/GB on its own.

Copy src/registry_mcp/registries/xx/ to registries/<cc>/, implement four methods, add one import line — nothing in core/ changes, and both surfaces plus the manifests light up for the new country automatically.

→ CONTRIBUTING.md — "Add your country", and the new country issue template to claim one first.

Development

uv sync --all-extras
uv run pytest          # `-m "not live"` to skip the tests that hit the real registry
uv run mypy .
uv run ruff check .

Layout:

src/registry_mcp/core/        country-neutral models, Registry ABC, rules, date helpers
src/registry_mcp/registries/  one folder per country — no/ (Norway), gb/ (UK), xx/ (template)
src/registry_mcp/api/         FastAPI REST surface
src/registry_mcp/mcp/         FastMCP server (stdio + Streamable HTTP at /mcp)

Documents

• NORBIZ_SPEC.md — technical spec of the Norwegian module
• UK_SPEC.md — technical spec of the UK module
• DECISIONS.md — interface and schema decisions
• KEYWORDS.md — the canonical alias list
• SUBMISSIONS.md — registry submission status
• legal/terms.md — terms of use and data attribution

Data source and licence

Norwegian data comes from Enhetsregisteret (Brønnøysundregistrene), published under NLOD 2.0 — attribution required. UK data comes from the Companies House public register, Crown copyright, free to re-use with no attribution condition; we cite it anyway. Every response carries source, source_url and license so the attribution travels with the data. This project's own code is MIT licensed. Not affiliated with or endorsed by Brønnøysundregistrene or Companies House.