Reexpress MCP Server

What does “Reexpress” MCP Server do?

Reexpress MCP Server is a tool designed to enhance Large Language Model (LLM) workflows, particularly for software development and data science. It acts as a drop-in Model Context Protocol (MCP) server that provides state-of-the-art statistical verification for LLM outputs using the Similarity-Distance-Magnitude (SDM) estimator. This estimator combines results from multiple models (such as GPT-4, o4-mini, and text-embedding-3-large) to deliver robust confidence estimates for LLM-generated content. The Reexpress MCP Server enables tasks like verifying answers to queries, refining responses based on statistical feedback, and adapting verification to user-specific tasks. It processes data locally (on Apple silicon Macs) and supports integration with external data through explicit file access controls, making it a reliable “second opinion” tool for mission-critical AI workflows.

List of Prompts

• No explicit prompt templates are listed in the repository documentation.

List of Resources

• No explicit MCP resource primitives are described in the provided documentation or files.

List of Tools

• Reexpress: Performs statistical verification of LLM outputs using the SDM estimator.
• ReexpressAddTrue: Marks a verification outcome as correct, updating the SDM estimator.
• ReexpressAddFalse: Marks a verification outcome as incorrect, updating the SDM estimator.
• ReexpressDirectorySet: Explicitly specifies directories whose files can be accessed and sent to LLM APIs.
• ReexpressFileSet: Explicitly specifies files that can be accessed and sent to LLM APIs.

Use Cases of this MCP Server

• AI Output Verification: Provides statistical confidence estimates for LLM responses, helping developers assess the reliability of AI-generated content.
• Interactive Code and Data Review: Ensures code snippets, analyses, or data science outputs generated by LLMs are statistically validated before use.
• Dynamic Task Adaptation: Allows users to adapt the verification model to their specific needs by marking outputs as true or false, improving future verifications.
• Controlled File Access: Offers a secure and explicit way to allow LLMs to access only designated files or directories during interactions, protecting sensitive data.
• Agentic Reasoning with SDM: Enables LLM agents to refine their answers or request clarification based on verification feedback, supporting more advanced, autonomous workflows.

How to set it up

Windsurf

1. Prerequisites: Ensure Node.js is installed.
2. Configuration File: Locate your Windsurf configuration file.
3. Add Reexpress MCP Server: Insert the following JSON snippet into the mcpServers object:

   {
     "reexpress": {
       "command": "npx",
       "args": ["@reexpress/mcp-server@latest"]
     }
   }
   

4. Save and Restart: Save your configuration and restart Windsurf.
5. Verify: Confirm that the Reexpress MCP Server is available in your MCP client.

Securing API Keys Example

{
  "reexpress": {
    "command": "npx",
    "args": ["@reexpress/mcp-server@latest"],
    "env": {
      "ANTHROPIC_API_KEY": "<your_api_key>"
    },
    "inputs": {
      "api_key": "${env.ANTHROPIC_API_KEY}"
    }
  }
}

Claude

1. Prerequisites: Ensure you have Claude Desktop or Claude MCP client installed.
2. Configuration File: Open the Claude MCP configuration panel.
3. Add Reexpress MCP Server: Add the following entry:

   {
     "reexpress": {
       "command": "npx",
       "args": ["@reexpress/mcp-server@latest"]
     }
   }
   

4. Save and Restart: Save the configuration and restart Claude.
5. Verify: Check that the Reexpress MCP Server appears and is selectable.

Securing API Keys Example

{
  "reexpress": {
    "command": "npx",
    "args": ["@reexpress/mcp-server@latest"],
    "env": {
      "ANTHROPIC_API_KEY": "<your_api_key>"
    },
    "inputs": {
      "api_key": "${env.ANTHROPIC_API_KEY}"
    }
  }
}

Cursor

1. Prerequisites: Install Node.js if not present.
2. Configuration File: Open the Cursor mcpServers settings.
3. Add Reexpress MCP Server: Include:

   {
     "reexpress": {
       "command": "npx",
       "args": ["@reexpress/mcp-server@latest"]
     }
   }
   

4. Save and Restart: Apply changes and restart Cursor.
5. Verify: Confirm the MCP server is listed in Cursor’s tools.

Securing API Keys Example

{
  "reexpress": {
    "command": "npx",
    "args": ["@reexpress/mcp-server@latest"],
    "env": {
      "ANTHROPIC_API_KEY": "<your_api_key>"
    },
    "inputs": {
      "api_key": "${env.ANTHROPIC_API_KEY}"
    }
  }
}

Cline

1. Prerequisites: Ensure Node.js is installed.
2. Configuration File: Open your Cline configuration file.
3. Add Reexpress MCP Server: Add:

   {
     "reexpress": {
       "command": "npx",
       "args": ["@reexpress/mcp-server@latest"]
     }
   }
   

4. Save and Restart: Save changes and restart Cline.
5. Verify: Ensure the MCP server is running and recognized.

Securing API Keys Example

{
  "reexpress": {
    "command": "npx",
    "args": ["@reexpress/mcp-server@latest"],
    "env": {
      "ANTHROPIC_API_KEY": "<your_api_key>"
    },
    "inputs": {
      "api_key": "${env.ANTHROPIC_API_KEY}"
    }
  }
}

How to use this MCP inside flows

Using MCP in FlowHunt

To integrate MCP servers into your FlowHunt workflow, start by adding the MCP component to your flow and connecting it to your AI agent:

Click on the MCP component to open the configuration panel. In the system MCP configuration section, insert your MCP server details using this JSON format:

{
  "reexpress": {
    "transport": "streamable_http",
    "url": "https://yourmcpserver.example/pathtothemcp/url"
  }
}

Once configured, the AI agent is now able to use this MCP as a tool with access to all its functions and capabilities. Remember to change “reexpress” to whatever the actual name of your MCP server is and replace the URL with your own MCP server URL.

Overview

| Roots Support | ⛔ | No mention of Roots concept in documentation or README.md |

Based on the tables above, the Reexpress MCP Server scores well for core LLM verification functionality and developer focus, but lacks thorough documentation for prompts, resources, and advanced MCP features like Roots or Sampling.

Our opinion

The Reexpress MCP Server is a focused and innovative MCP server for statistical verification, with solid documentation for setup and use, but lacks some breadth in MCP-specific primitives and advanced features. Good for targeted use-cases.

MCP Score