MCP Setup Guide
Connect the Klardaten DATEV MCP server to your AI tools using OAuth 2.1.
This guide explains how to connect clients to the Klardaten DATEV MCP server using OAuth 2.1.
Endpoint: https://api.klardaten.com/mcp
Open WebUI
- In the admin panel, open Settings → Integrations.

- Under "Manage Tool Servers", click Add (+).
- Set the connection type to "MCP Streamable HTTP" (not OpenAPI).
- Fill in the connection details:
- Name: Klardaten
- ID:
e.g. klardaten - URL:
https://api.klardaten.com/mcp
- For authentication, choose "OAuth 2.1".
- Click "Register Client" to verify the connection. You can also restrict which users may use the MCP server.
- Click "Save" to close the dialog.

Use the MCP server in a chat
- Open a new chat.
- Choose Tools → Klardaten to start the OAuth login flow.

On the login screen, sign in with either:
- your Klardaten user email and password, or
- your user API key

After you confirm, the tool should be available in the chat. You can then work with your instance data through the MCP connection.
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- Add an "MCP Client" node to your workflow.
- Configure it:
- MCP Endpoint URL:
https://api.klardaten.com/mcp - Authentication: MCP OAuth
- MCP Endpoint URL:
- Create a new credential under "Credential for MCP OAuth2 API".

- In the credential:
- Leave "Use Dynamic Client Registration" enabled.
- Set "Server URL" to https://api.klardaten.com/mcp.
- Click "Connect to MCP".

You will see the same OAuth flow as in Open WebUI.

When authorization finishes, the tool list should show the available DatevConnect tools.
