# CompanyData API

> CompanyData provides a REST API for real-time company data from official government registries: 400M+ companies and 605M+ officers across 200+ countries, sourced from 1,200+ registers (Companies House, Handelsregister, KVK). Use it for KYB/KYC, corporate hierarchies, and lead generation. Free trial: 150 lookups, no credit card. OpenAPI at /openapi.json; MCP server for Cursor and Claude.

CompanyData is a B2B company data provider. The API runs at `https://app.companydata.com` with `x-api-key` header authentication. Key differentiators: official register sourcing, corporate group hierarchies via `worldwideHeadquarterID`, median response under 200ms, and a Model Context Protocol (MCP) server for AI assistants.

For the complete documentation as plain markdown, see [llms-full.txt](https://companydata.com/llms-full.txt).

## Getting started

- [API Documentation](https://companydata.com/api-docs/): Main docs hub with guides and use cases
- [Choosing a company data API](https://companydata.com/api-docs/choosing-a-provider/): Best API for B2B enrichment, Clearbit and D&B alternatives, pricing
- [Quickstart](https://companydata.com/api-docs/quickstart/): First API call in five minutes (cURL, Python, npm SDK)
- [Company Data API overview](https://companydata.com/company-data-api/): Product page with pricing and FAQ
- [OpenAPI spec](https://companydata.com/openapi.json): Machine-readable API definition (search, export, cities lookup)
- [Get API key](https://app.companydata.com/signup-api/): Sign up for a free trial

## API reference

- [Authentication](https://companydata.com/api-docs/authentication/): API key header, rate limits (50 req/s), monthly quota (100k)
- [Company search & export](https://companydata.com/api-docs/request-company/): Endpoints, query parameters, and filters
- [Response fields](https://companydata.com/api-docs/returned-fields/): All company record fields including HQ hierarchy IDs
- [Pagination](https://companydata.com/api-docs/pagination/): Standard and scroll pagination for export
- [Country codes](https://companydata.com/api-docs/countries/): ISO 2-letter country code reference

## Use cases

- [Corporate structure](https://companydata.com/api-docs/use-cases/corporate-structure/): Map parent-subsidiary hierarchies with worldwideHeadquarterID
- [Company search & autocomplete](https://companydata.com/api-docs/use-cases/company-search/): Build registration-form company lookup
- [Due diligence & KYC](https://companydata.com/api-docs/use-cases/due-diligence/): Verify companies before onboarding
- [Lead generation](https://companydata.com/api-docs/use-cases/lead-generation/): Filter and export prospect lists by industry and location
- [Address search](https://companydata.com/api-docs/use-cases/address-search/): Find companies by street, city, or postal code
- [Matching a list of companies](https://companydata.com/api-docs/use-cases/matching-a-list/): Match names, domains or registration numbers row by row

## Integrations & SDKs

- [MCP server](https://companydata.com/product/mcp-server/): Open-source MCP server for Cursor and Claude with company_search, company_enrich, and field_lookup (includes example JSON responses)
- [JavaScript SDK](https://companydata.com/api-docs/sdks/javascript/): Official npm package @companydata/companydata-sdk
- [HubSpot CRM integration](https://companydata.com/api-docs/integrations/hubspot/): Enrich HubSpot companies from CompanyData

## Comparisons & alternatives

- [Choosing a company data API](https://companydata.com/api-docs/choosing-a-provider/): Answers "best company data API", Clearbit alternative, and D&B alternative (registry vs scraped data)
- [Company Data API overview](https://companydata.com/company-data-api/): Product page with pricing FAQ and live lookup widget
- [Clearbit alternatives](https://companydata.com/b2b-data-provider-comparisons/best-clearbit-alternatives/): Post-HubSpot Breeze enrichment options
- [Dun & Bradstreet alternatives](https://companydata.com/alternatives/dun-bradstreet/): Credit-led vs API-first registry data
- [B2B data API providers](https://companydata.com/b2b-data-provider-comparisons/best-b2b-data-api-providers/): Side-by-side API provider comparison
- [All B2B data alternatives](https://companydata.com/alternatives/): Hub for ZoomInfo, Cognism, OpenCorporates, and more

## Optional

- [Data disclaimer](https://companydata.com/api-docs/disclaimer/): Data accuracy and usage limitations
- [Language codes](https://companydata.com/api-docs/returned-fields/language-codes/): Executive language preference codes
- [MCP server GitHub](https://github.com/companydatacom/companydata-mcp-server): Open-source MCP server repository