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Applies to:
  • Plan -
  • Deployment -
Summary When using MCP server with hybrid deployments, authentication may fail with a “data plane mismatch” error because the server connects to the default control plane instead of your organization’s custom data plane URL. This occurs when your organization is configured to use a CloudFront-based data plane endpoint. Configure the MCP server to use the MCP URL shown in Settings > Data plane to resolve the authentication failure.

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Problem

MCP server authentication fails with data plane mismatch error when your organization uses a custom data plane endpoint.

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Configuration Steps

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Step 1: Find your MCP URL

Go to Settings > Data plane and copy the value in the MCP URL card (for example, https://d8k4dyx7j51un.cloudfront.net/mcp). This is your data plane’s API URL with the /mcp path appended.

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Step 2: Configure MCP server with your MCP URL

Remove existing Braintrust MCP configuration and add it with your MCP URL:

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Step 3: Verify configuration

Restart Claude and test MCP server connection to confirm it routes to your data plane.

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Known Limitations

The Braintrust Claude Code plugin does not support custom data plane URLs. Use direct MCP setup as shown above instead of the plugin for hybrid deployments.