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