Langchain Integration MCP server

The Langchain TypeScript with MCP Tools Integration enables you to interact with Language Models while executing various tools through a chat interface using the Model Context Protocol. This integration provides a seamless way to combine the power of LLMs with practical utility functions.

Prerequisites

• Node.js (v14 or higher)
• npm
• Ollama server running locally
• MCP server running locally

Installation

Follow these steps to get the MCP tools integration up and running:

1. Clone the repository:

   git clone https://github.com/shashwat001/mcptools-langchain-integration.git
   cd mcptools-langchain-integration
   

2. Install dependencies:

   npm install
   

Configuration

Configuring Ollama

The project uses Ollama for LLM integration. You can configure Ollama settings in src/llm.js:

export const ollamaConfig = {
    baseUrl: "http://localhost:11434",
    model: "llama3.1:8b-instruct-q6_K",
    temperature: 0.1,
    maxRetries: 2
};

Setting up the MCP Server

MCP server settings can be adjusted in the same file:

export const mcpConfig = {
    serverUrl: 'http://localhost:7000/sse',
    clientInfo: {
        name: 'ollama-client',
        version: '1.0.0'
    }
};

Customizing the System Prompt

The system prompt that guides tool interactions can be modified in src/llm.js:

export const systemPromptForTools = "In this environment you have access to a set of tools you can use to answer the user's question.\n Don't ask user to execute the functions and decide yourself whether to call the tool or not.\nNever call more than one tool at a time.";

Running the Application

Before starting the application, ensure that:

1. The Ollama server is running on http://localhost:11434
2. The MCP server is running on http://localhost:7000

Then launch the application with:

node src/index.js

Key Features

• Interactive Chat Interface: Communicate with the LLM through a conversational interface
• MCP Tool Integration: Access and execute various tools directly from your chat
• SSE Support: Works with Server-Sent Events based MCP servers

Usage Notes

Security Considerations

Important: Exercise caution when using the MCP server as it has write permissions that could make unintended system changes. Always review tool permissions before execution to ensure you understand what actions the system might take.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "langchain-integration" '{"command":"node","args":["src/index.js"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "langchain-integration": {
            "command": "node",
            "args": [
                "src/index.js"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "langchain-integration": {
            "command": "node",
            "args": [
                "src/index.js"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect