What is Mcp Payment Example

mcp-payment-example is a production-ready payment system implementation that utilizes the Model Context Protocol (MCP) framework for seamless integration between AI models and application tools.

Use cases

Use cases include testing payment systems interactively, automating payment processing through AI models, and generating reports based on payment data.

How to use

To use mcp-payment-example, clone the repository and install the necessary dependencies. You can run it in Development Mode for testing with an interactive inspector or in Production Mode for actual deployment.

Key features

Key features include interactive development and testing capabilities, AI model integration for automated processing, and support for both basic and enhanced implementations.

Where to use

mcp-payment-example can be used in various domains such as e-commerce, financial services, and any application requiring automated payment processing and AI integration.

Building AI-Powered Payment Systems with Model Context Protocol (MCP)

Introduction

The Model Context Protocol (MCP) framework enables seamless integration between AI models and your application’s tools and data.

This repository demonstrates a production-ready payment system implementation that can be used in two ways:

1. Interactive Development & Testing: Use the MCP Inspector to interact with and test the payment system directly

2. AI Integration: Connect the payment system to AI models for automated processing

Repository Setup

Clone this repository to explore and run the payment system locally:

git clone https://github.com/jagreehal/mcp-payment-example
cd mcp-payment-example

Prerequisites

• Bun runtime environment
• Node.js v18 or higher
• Git

Local Development

1. Install dependencies:

   bun install
   

2. Choose your implementation:

   Development Mode (Recommended)

   # Basic implementation with interactive inspector
   npx @modelcontextprotocol/inspector bun src/basic.ts
   
   # Enhanced implementation with interactive inspector
   npx @modelcontextprotocol/inspector bun src/enhanced.ts
   

   Production Mode

   # Basic implementation
   bun run start:basic
   
   # Enhanced implementation
   bun run start:enhanced
   

System Overview

Architecture

graph TD
    A[AI Model/LLM] -->|Requests| B[MCP Client]
    B -->|Protocol| C[MCP Server]
    C -->|Tools| D[Payment Processing]
    C -->|Resources| E[Currency Rates]
    C -->|Prompts| F[Report Generation]
    D -->|Logging| G[Logger]
    E -->|Updates| H[External API]

    style A fill:#f9f,stroke:#333,stroke-width:2px
    style B fill:#bbf,stroke:#333,stroke-width:2px
    style C fill:#dfd,stroke:#333,stroke-width:2px

Data Flow

sequenceDiagram
    participant U as User/AI
    participant M as MCP Server
    participant D as Database
    participant L as Logger

    U->>M: Request Payment
    M->>L: Log Request
    M->>D: Process Payment
    D-->>M: Confirm Payment
    M->>L: Log Result
    M-->>U: Return Response

Getting Started

# Installation
git clone https://github.com/jagreehal/mcp-payment-example
cd mcp-payment-example
bun install

# Development Mode with MCP Inspector
npx @modelcontextprotocol/inspector bun src/basic.ts     # Basic implementation
npx @modelcontextprotocol/inspector bun src/enhanced.ts  # Enhanced implementation

# Production Mode
bun run start:basic    # Basic implementation
bun run start:enhanced # Enhanced implementation

Implementation Options

Basic Implementation (src/basic.ts)

The basic implementation provides core payment functionality suitable for learning and testing:

• GBP-only payments
• Standard error handling
• Structured logging
• Essential payment tools:
  • Payment Summary
  • Payment Details
  • Fraud Alert

Enhanced Implementation (src/enhanced.ts)

The enhanced implementation offers production-ready features:

• Multi-currency support
• Advanced fraud detection
• Resource management
• Comprehensive error handling
• Full audit logging
• Extended toolset

Configuration

For Interactive Development (MCP Inspector)

No configuration needed! Just run the MCP Inspector commands from the Quick Start section:

npx @modelcontextprotocol/inspector bun src/basic.ts     # or
npx @modelcontextprotocol/inspector bun src/enhanced.ts

For AI Integration

If you want to connect the payment system to AI models like Claude, you’ll need to configure the claude_desktop_config.json file:

💡 Tip: To get your workspace path, run pwd in your terminal while in the project directory:

cd mcp-payment-example
pwd  # This will output your workspace path, e.g., /Users/username/dev/mcp-payment-example

{
  "mcpServers": {
    "payments-basic": {
      "command": "bun",
      "args": [
        "run",
        "{pwd_output_from_above}/src/basic.ts"
      ]
    },
    "payments-enhanced": {
      "command": "bun",
      "args": [
        "run",
        "{pwd_output_from_above}/src/enhanced.ts"
      ]
    }
  }
}

Configuration options for AI integration:

• mcpServers: Object containing named server configurations
• command: The command to run the server (e.g., “bun” or “node”)
• args: Array of arguments including:
  • Script to run with absolute path (e.g., “/Users/username/dev/mcp-payment-example/src/basic.ts”)

💡 Important:

• For development and testing, use the MCP Inspector approach - it’s simpler and more interactive
• Only set up claude_desktop_config.json when you need to integrate with AI models
• Make sure to use absolute paths (starting with /) from your pwd output
• Remove any comments in your actual JSON config file

Example Usage

Basic Implementation (src/basic.ts)

The basic implementation provides essential payment functionality with a simple set of tools. Start with this if you’re new to MCP or need basic payment processing.

# Run the basic implementation
npx @modelcontextprotocol/inspector bun src/basic.ts

Available Tools

1. Payment Summary

   // Request
   "Show payment summary for user U123 with details"
   
   // Response
   User U123 has 3 payments totalling £350.
   

2. Payment Details

   // Request
   "Show payments with status pending"
   
   // Response
   Payments with status 'pending':
   - £200.00 to Bob (3 days ago)
   

3. Fraud Alert

   // Request
   "Check for fraud alerts for user U123 with threshold 100"
   
   // Response
   Alert: Found 2 suspicious payments. Please review for potential fraud.
   

Enhanced Implementation (src/enhanced.ts)

The enhanced implementation adds multi-currency support, fraud detection, and advanced reporting. Use this for production-ready payment processing.

# Run the enhanced implementation
npx @modelcontextprotocol/inspector bun src/enhanced.ts

Available Tools

1. Payment Summary (Enhanced)

   // Request
   "Show payment summary for user U123 in EUR for the last week"
   
   // Response
   Payment Summary for U123 (Last Week):
   Total: €432.50
   Number of Transactions: 3
   

2. Add Payment

   // Request
   "Add payment of €75 to John for lunch"
   
   // Response
   Payment added successfully:
   ID: P1234567890
   Amount: €75.00
   Recipient: John
   Status: pending
   

3. Fraud Check

   // Request
   "Run detailed fraud check for user U123 with threshold 500"
   
   // Response
   Fraud Check Report (Detailed):
   Risk Level: Medium
   Suspicious Activities:
   - Large payment: €2000 on 2024-03-10
   - Multiple international transfers detected
   

Available Resources

1. Currency Exchange Rates

   // Request
   "Get current exchange rates"
   
   // Response
   Current Exchange Rates:
   GBP: 1.00
   EUR: 1.15
   USD: 1.27
   JPY: 190.5
   Last Updated: 2024-03-10T14:30:00Z
   

Security Features

1. Input Validation

   • Currency code validation
   • Transaction limits
   • Payee name sanitisation

2. Audit Logging

   // Structured audit log example
   toolsLogger.info(
     {
       payment: {
         id: 'P123',
         amount: 75.0,
         currency: 'GBP',
         timestamp: '2024-03-10T12:00:00Z',
       },
     },
     'Payment processed successfully',
   );
   

3. Exception Handling

   try {
     await processPayment(details);
   } catch (error) {
     logger.error({ error, details }, 'Payment processing failed');
     return createErrorResponse('Unable to process payment');
   }
   

Troubleshooting Guide

Common issues and their solutions:

1. Connection Issues

   Error: Failed to create transport
   

   ➡️ Verify network connectivity and port availability

2. Currency Support

   Error: Unsupported currency: XYZ
   

   ➡️ Use supported currencies: GBP, EUR, USD, JPY

3. Transaction Limits

   Error: Amount exceeds maximum (£10,000)
   

   ➡️ Ensure amount is within authorised limits

Best Practices

1. Audit Logging

   • Implement component-specific loggers
   • Include contextual transaction data
   • Set appropriate logging levels

2. Exception Management

   • Implement comprehensive error handling
   • Provide clear error messages
   • Include detailed error context

3. Security Measures

   • Validate all inputs thoroughly
   • Implement data sanitisation
   • Enforce proper authentication

Official Documentation

• MCP SDK Documentation
• MCP Inspector Documentation
• MCP Technical Overview

Licence

MIT