MCP

The OpenRegister MCP Server enables AI assistants and agent frameworks to interact with the OpenRegister API through the Model Context Protocol. It exposes company search and data retrieval as tools that any MCP-compatible client can use. There are two ways to connect: the remote MCP server (no local setup needed) or the local npm package (for full control).

Remote MCP Server

The easiest way to connect — no local installation required. The server handles authentication via OAuth when you connect.

Transport	Endpoint
SSE (legacy)	`https://mcp.openregister.de/sse`
Streamable HTTP	`https://mcp.openregister.de/mcp`

Use in AI Assistants

Connect directly in your browser — no terminal or config files needed.

Claude.ai
ChatGPT

Claude.ai supports MCP servers natively through its Integrations settings.

Open Claude.ai and go to Settings → Integrations
Click + Add or + Add Custom Integration
Enter the URL: https://mcp.openregister.de/sse
Follow the authorization flow to connect your API key

ChatGPT supports MCP servers via its Connectors feature (requires Developer Mode).

Open ChatGPT and go to Settings → Advanced
Enable Developer Mode
Go to Settings → Connectors → + Add Custom Connector
Enter the URL: https://mcp.openregister.de/mcp
Follow the authorization flow to connect your API key

Use in Developer Tools

Edit a config file and restart your client. Requires Node.js 18+.

Claude Desktop
Cursor

Edit your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "openregister": {
      "command": "npx",
      "args": ["-y", "mcp-remote@latest", "https://mcp.openregister.de/sse"]
    }
  }
}

Restart Claude Desktop. Look for the hammer icon (🔨) to confirm the connection.

Edit ~/.cursor/mcp.json:

{
  "mcpServers": {
    "openregister": {
      "command": "npx",
      "args": ["-y", "mcp-remote@latest", "https://mcp.openregister.de/sse"]
    }
  }
}

Restart Cursor to activate the connection.

Build with It

Use the MCP server as a tool source in your own AI agents and pipelines.

OpenAI Agents SDK
Vercel AI SDK

from agents import Agent, Runner
from agents.mcp import MCPServerStreamableHttp

async def main():
    async with MCPServerStreamableHttp(
        url="https://mcp.openregister.de/mcp",
        headers={"Authorization": "Bearer YOUR_API_KEY"},
    ) as mcp_server:
        agent = Agent(
            name="company-researcher",
            instructions="Use OpenRegister tools to look up German company data.",
            mcp_servers=[mcp_server],
        )
        result = await Runner.run(agent, "Find information about Trade Republic Bank GmbH")
        print(result.final_output)

import { createOpenAI } from "@ai-sdk/openai";
import { experimental_createMCPClient, generateText } from "ai";

const mcpClient = await experimental_createMCPClient({
  transport: {
    type: "sse",
    url: "https://mcp.openregister.de/sse",
    headers: { Authorization: "Bearer YOUR_API_KEY" },
  },
});

const tools = await mcpClient.tools();

const { text } = await generateText({
  model: createOpenAI({ apiKey: process.env.OPENAI_API_KEY })("gpt-4o"),
  tools,
  prompt: "Find information about Trade Republic Bank GmbH",
});

await mcpClient.close();

The remote MCP server requires Node.js 18 or higher for mcp-remote. If you encounter connection issues, try clearing the MCP auth cache: rm -rf ~/.mcp-auth

Local MCP Server (npm)

Run the MCP server locally with your API key for full control. Repository: openregister-typescript/packages/mcp-server

export OPENREGISTER_API_KEY="your-api-key"
npx -y openregister-mcp@latest

For MCP clients that use configuration JSON (like Claude Desktop), add this configuration:

{
  "mcpServers": {
    "openregister": {
      "command": "npx",
      "args": ["-y", "openregister-mcp", "--client=claude", "--tools=all"],
      "env": {
        "OPENREGISTER_API_KEY": "your-api-key"
      }
    }
  }
}

Authentication

Set your OpenRegister API key as an environment variable:

export OPENREGISTER_API_KEY="your-api-key-here"

Get your API key from OpenRegister Keys. For more detailed configuration options and advanced usage, see the full repository documentation.

Overview

Data Sources

Guides

Integration

Remote MCP Server

Use in AI Assistants

Use in Developer Tools

Build with It

Local MCP Server (npm)

Authentication

​Remote MCP Server

​Use in AI Assistants

​Use in Developer Tools

​Build with It

​Local MCP Server (npm)

​Authentication

Remote MCP Server

Use in AI Assistants

Use in Developer Tools

Build with It

Local MCP Server (npm)

Authentication