What is React Agent With Mcp

react-agent-with-mcp is a template that showcases a ReAct agent implemented using LangGraph and the Model Context Protocol (MCP). It leverages advanced AI techniques to facilitate interactive applications.

Use cases

Use cases include developing customer support chatbots, creating interactive educational tools, and building AI assistants that require context-aware interactions.

How to use

To use react-agent-with-mcp, clone the repository from GitHub, set up the necessary environment, and follow the instructions in the README to integrate the agent into your application.

Key features

Key features include integration with LangGraph for building interactive agents, support for the Model Context Protocol (MCP), and a focus on ReAct agent capabilities for enhanced user interaction.

Where to use

react-agent-with-mcp can be used in various fields such as AI-driven applications, interactive chatbots, and any domain requiring advanced user interaction through AI.

LangGraph ReAct Agent with MCP

This template showcases a ReAct agent implemented using LangGraph and the Model Context Protocol (MCP). The agent uses MCP servers to provide tools and capabilities through a unified gateway.

Architecture

The system consists of three main components:

1. MCP Gateway Server: A server that:

   • Manages multiple MCP server processes
   • Provides a unified API for accessing tools
   • Handles communication with MCP servers
   • Exposes tools through a simple HTTP interface

2. MCP Servers: Individual servers that provide specific capabilities:

   • Filesystem Server: File operations (read, write, list, search)
   • Memory Server: Knowledge graph operations (entities, relations, queries)
   • Additional servers can be added for more capabilities

3. ReAct Agent: The agent that:

   • Connects to the MCP gateway
   • Discovers available tools
   • Uses tools to accomplish tasks
   • Combines capabilities from multiple servers

Getting Started

1. Install Dependencies

# Install the agent package
pip install -e .

# Install the gateway package
cd gateway
pip install -e .
cd ..

2. Configure MCP Servers

The gateway server is configured through gateway/config.json. By default, it starts two MCP servers:

{
  "mcp": {
    "servers": {
      "filesystem": {
        "command": "npx",
        "args": [
          "-y",
          "@modelcontextprotocol/server-filesystem",
          "/path/to/directory"
        ]
      },
      "memory": {
        "command": "npx",
        "args": [
          "-y",
          "@modelcontextprotocol/server-memory"
        ]
      }
    }
  }
}

You can add more servers from the official MCP servers repository.

3. Start the Gateway Server

cd gateway
python -m mcp_gateway.server

The server will start on port 8808 by default.

4. Configure the Agent

The agent’s connection to the gateway is configured in langgraph.json:

{
  "dependencies": [
    "."
  ],
  "graphs": {
    "agent": "./src/react_agent/graph.py:graph"
  },
  "env": ".env",
  "mcp": {
    "gateway_url": "http://localhost:8808"
  }
}

5. Use the Agent

Open your app in LangGraph! Install guide here.

This will open a new browser window with the agent running. The agent will automatically:

1. Connect to the local gateway server
2. Discover available tools
3. Make tools available for use in conversations

Available Tools

The agent has access to tools from both MCP servers:

Filesystem Tools

• read_file: Read file contents
• write_file: Create or update files
• list_directory: List directory contents
• search_files: Find files matching patterns
• And more…

Memory Tools

• create_entities: Add entities to knowledge graph
• create_relations: Link entities together
• search_nodes: Query the knowledge graph
• And more…

Development

Adding New MCP Servers

1. Find a server in the MCP servers repository
2. Add its configuration to gateway/config.json
3. The agent will automatically discover its tools

Customizing the Agent

• Modify the system prompt in src/react_agent/prompts.py
• Update the agent’s reasoning in src/react_agent/graph.py
• Add new capabilities by including more MCP servers

Documentation

• LangGraph Documentation
• Model Context Protocol
• MCP Servers Repository

License

This project is licensed under the MIT License - see the LICENSE file for details.