MCP Index Blog: Guides for Model Context Protocol Servers

Introduction

The Model Context Protocol (MCP) is an open standard developed by Anthropic that standardizes how applications provide context and tools to Large Language Models (LLMs). This guide will walk you through integrating MCP with Cursor, a powerful AI-enhanced code editor, allowing you to extend Cursor's capabilities by connecting it to various data sources and tools through standardized interfaces.

What is MCP?

MCP acts as a bridge between your code and the data it requires, ensuring seamless integration with diverse data sources, including:

APIs
Cloud databases
Local files
Development environments
Business tools
Content repositories

Key Benefits:

Context Management: Ensures your AI models have access to the context they need
Plug-and-Play Integration: Straightforward process requiring minimal configuration
Enhanced Model Performance: Improves contextual understanding of models
Flexibility: Adapts to your specific needs

Why Integrate MCP with Cursor?

Cursor already offers powerful AI capabilities for coding assistance, but with MCP integration, you can:

Connect to external systems and data sources
Integrate with existing tools and infrastructure
Allow Cursor to query databases directly
Enable reading from various knowledge bases
Create custom tools specific to your workflow

Architecture Overview

MCP Architecture

The MCP architecture consists of:

MCP Hosts: Programs like Cursor that want to access data through MCP
MCP Clients: Protocol clients that maintain connections with servers
MCP Servers: Lightweight programs that expose specific capabilities through the standardized protocol
Local Data Sources: Your computer's files, databases, and services
Remote Services: External systems available over the internet

Setting Up MCP in Cursor

Prerequisites

Cursor version 0.45.7 or later
Node.js installed for running JavaScript-based MCP servers
Basic understanding of the terminal/command line

Step 1: Enable MCP in Cursor Settings

Open Cursor
Navigate to Settings > Features
Find and enable the "MCP Servers" option

Step 2: Configure MCP Servers

MCP server configurations can be added in two ways:

Method 1: Configuration File (Recommended)

Create or edit the MCP configuration file at one of these locations:

macOS: ~/Library/Application Support/Cursor/mcp-servers.json
Windows: %APPDATA%\Cursor\mcp-servers.json
Linux: ~/.config/Cursor/mcp-servers.json

Example configuration:

{
  "servers": [
    {
      "name": "filesystem",
      "type": "command",
      "command": "npx -y @modelcontextprotocol/server-filesystem /path/to/directory"
    },
    {
      "name": "postgres",
      "type": "sse",
      "url": "http://localhost:3030"
    }
  ]
}

Method 2: UI Configuration

Navigate to Settings > Features > MCP Servers
Click "Add MCP Server"
Fill in the required fields:
- Name
- Type (command or sse)
- Command or URL

Step 3: Install and Run MCP Servers

There are several pre-built MCP servers available. Here are some common examples:

Filesystem Server

npx -y @modelcontextprotocol/server-filesystem /path/to/directory

PostgreSQL Server

Install the server:

npm install -g @modelcontextprotocol/server-postgres

Run the server:

mcp-postgres --connection-string "postgresql://username:password@localhost:5432/database"

SQLite Server

npx -y @modelcontextprotocol/server-sqlite /path/to/database.sqlite

Community and Third-Party Resources

MCP Index: A comprehensive directory of MCP servers, tools, and resources
GitHub Community Servers: Community-developed MCP server implementations

Using MCP Tools in Cursor

Once configured, you can use MCP tools within Cursor's Agent:

Open the Agent (Cmd+K or Ctrl+K)
Type your query that may require external data
Cursor will now be able to use the MCP tools to access external data

Tool Approval

By default, Cursor will ask for your approval before executing MCP tools. You can configure this behavior:

Navigate to Settings > Features > MCP Servers
Configure the "Tool Approval" setting:
- Always Ask: Prompt for approval for each tool execution (default)
- Yolo Mode: Execute tools without asking for approval

Example Usage

Here are some examples of what you can do with MCP in Cursor:

Database Integration

// In Cursor Agent
Query all users who signed up in the last month and format the results as a table

Cursor will:

Use the PostgreSQL MCP server to connect to your database
Generate and execute the appropriate SQL query
Format and display the results

File System Integration

// In Cursor Agent
Find all TODO comments in my project and organize them by priority

Cursor will:

Use the Filesystem MCP server to scan your project
Identify TODO comments
Analyze and organize them by priority

Creating Custom MCP Servers

You can create your own MCP servers to extend Cursor's capabilities further:

Choose a programming language (MCP servers can be written in any language)
Implement the MCP protocol specification
Expose the desired functionality as tools or resources

For detailed instructions on creating custom MCP servers, refer to the official MCP documentation.

Limitations and Considerations

Tool Quantity: Cursor currently supports up to 40 tools from MCP servers.
Remote Development: MCP servers may not work properly when accessing Cursor over SSH or other remote development environments.
MCP Resources: While MCP offers both tools and resources, Cursor currently only supports tools. Resource support is planned for future releases.

Troubleshooting

Common Issues

MCP Server Not Connecting:
- Verify the server is running
- Check the URL or command is correct
- Ensure network access is not blocked by firewalls
Permission Errors:
- Ensure the MCP server has appropriate permissions to access the resources it needs
Performance Issues:
- Consider limiting the scope of data the MCP server has access to
- Use more specific queries to reduce processing time

Conclusion

Integrating MCP with Cursor creates a powerful development environment that combines AI-assisted coding with seamless access to external data sources and tools. By following this guide, you've learned how to set up and configure MCP servers, use them within Cursor, and troubleshoot common issues.

For further information, refer to the official documentation: