# Developers — RMG Circular

> RMG Circular is API-first: every capability exists first as a versioned endpoint and an MCP tool, and the human interface consumes it. All of it is public, unauthenticated and rate limited.

## REST API

- `GET https://rmgcircular.com/api/v1/health` — Liveness check. Calls no upstream service.
- `GET https://rmgcircular.com/api/v1/company/{cui}` — Romanian company data by CUI, from the ANAF public VAT-payer registry.
- `GET https://rmgcircular.com/api/v1/openapi.json` — The OpenAPI 3.1 description, generated from the same definitions the code dispatches on.

## MCP server

MCP endpoint over Streamable HTTP, stateless and unauthenticated. POST JSON-RPC to it. The tools call exactly the same modules as the REST API.

- `POST https://rmgcircular.com/mcp`

## For agents

Every page has a Markdown twin at the same path with a .md extension, and also answers the Accept: text/markdown header. See llms.txt for an overview.

- https://rmgcircular.com/llms.txt

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Every response carries its source and the time the data was retrieved. Information only, not legal advice.
This page is the Markdown twin of the canonical HTML page.
Canonical HTML: https://rmgcircular.com/en/developers/