Public developer platform

API & MCP for Czech company data

Low-volume access without registration. Use REST in projects and Streamable HTTP MCP in AI agents.

REST quick start

curl

curl https://rejstr.cz/api/v1/subjects/28862961

JavaScript

const response = await fetch('https://rejstr.cz/api/v1/search?q=alfa');
const result = await response.json();

Python

import requests
result = requests.get('https://rejstr.cz/api/v1/subjects/28862961').json()

REST API reference

GET /api/v1/subjects/{ico}

Company-only public profile by IČO (one to eight digits; shorter values are zero-padded). Anonymous limit: 60/min/IP. Shared cache, ETag and freshness metadata.

200 · 400 · 404 · 429 · Retry-After · public-core

GET /api/v1/search?q=&limit=&offset=

Company-name search. Anonymous limit: 15/min/IP; limit ≤ 10 and offset ≤ 100.

200 · 400 · 404 · 429 · Retry-After · public-core

Errors use BAD_REQUEST, NOT_FOUND, RATE_LIMITED, PAYLOAD_TOO_LARGE, UNAUTHORIZED and INTERNAL_ERROR. A sent invalid key returns 401; omitting a key uses anonymous quota.

MCP for AI agents

Canonical endpoint: https://rejstr.cz/mcp. Transport: stateless Streamable HTTP. No token is required.

Generic MCP configuration

{
  "mcpServers": {
    "rejstr": {
      "type": "streamable-http",
      "url": "https://rejstr.cz/mcp"
    }
  }
}

tool search_subjects({ query, limit? })

Search when the exact IČO is unknown.

200 · 400 · 404 · 429 · Retry-After · public-core

tool get_subject({ ico })

Preferred for exact factual answers; cite the public profile URL and data date.

200 · 400 · 404 · 429 · Retry-After · public-core

Clients with custom headers

Optionally send Authorization: Bearer <public-key> or X-API-Key for a higher quota. The returned data does not change.

Clients without remote MCP

Call the REST endpoints directly from your agent. A local stdio proxy may be added later; REST remains the source-equivalent fallback.

Instructions last verified: 21 July 2026.

Data, privacy and fair use

The public-core profile allowlists company data and excludes natural persons, birth data, residences, raw registry payloads and internal diagnostics. Do not use the service to profile people or evade limits.

Risk flags state what a source reported; they are not proof of fraud or a credit score. Factual answers should cite source URLs and freshness metadata.

Versioning and support

The /v1 contract receives additive changes. Breaking changes require a new version and a documented deprecation period.

Integration or security issue? Use the contact listed in the project and privacy pages.