MCP

Integrate the OpenRegister API into your AI assistant or application

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

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

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

ChatGPT

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

1. Open ChatGPT and go to Settings → Advanced
2. Enable Developer Mode
3. Go to Settings → Connectors → + Add Custom Connector
4. Enter the URL: https://mcp.openregister.de/mcp
5. 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

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.

Cursor

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

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)

Vercel AI SDK

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.