MCP Mortgage Server

A Model Context Protocol (MCP) server for parsing and analyzing mortgage documents (Loan Estimates & Closing Disclosures) using MISMO standards.

🎯 What is This?

This is a Model Context Protocol (MCP) server that allows AI assistants (like Claude Desktop, OpenAI Agents, etc.) to parse and analyze mortgage documents. It converts Loan Estimates (LE) and Closing Disclosures (CD) into structured MISMO-compliant JSON, and checks for TRID compliance violations.

Key Features

✅ MCP-Compliant - Works natively with Claude Desktop, OpenAI Agents SDK, and other MCP clients ✅ Secure - URL validation, SSRF prevention, file size limits, timeout protection ✅ Type-Safe - Pydantic models ensure data validation ✅ TRID Compliance - Automated tolerance checking (zero-tolerance, 10% tolerance) ✅ Resources - Access to MISMO schemas and mortgage glossary ✅ Prompts - Pre-built workflows for loan analysis

🚀 Quick Start

Prerequisites

• Python 3.10 or higher
• Claude Desktop (recommended) or another MCP-compatible client

Installation

1. Clone the repository:

   git clone https://github.com/confersolutions/mcp-mortgage-server.git
   cd mcp-mortgage-server

1. Install dependencies:

   pip install -r requirements.txt

1. Test the server:

   python test_server.py

You should see:

   ✓ All tests passed!
   Server is ready for MCP client connections!

Usage with Claude Desktop

1. Locate your Claude Desktop config file:

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

1. Add this server:

   {
     "mcpServers": {
       "mortgage": {
         "command": "python",
         "args": ["/full/path/to/mcp-mortgage-server/server.py"]
       }
     }
   }

1. Restart Claude Desktop

1. Use it in Claude:

   Can you parse this loan estimate and summarize the key terms?
   URL: https://storage.googleapis.com/mortgage-docs/sample-le.pdf

Claude will automatically call the appropriate MCP tool and parse the document.

🛠️ Available Tools

1. hello

Simple connectivity test.

Input: { "name": "World" }
Output: "Hello, World! MCP server is working correctly."

2. parse_loan_estimate

Parse a Loan Estimate PDF into MISMO-compliant JSON.

Input:

{
  "pdf_url": "https://storage.googleapis.com/mortgage-docs/le-12345.pdf"
}

Output:

{
  "loan_amount": 300000.0,
  "interest_rate": 6.5,
  "apr": 6.73,
  "monthly_payment": 1896.20,
  "total_closing_costs": 12000.00,
  "origination_charges": 1500.00,
  ...
}

Security: Only HTTPS URLs from whitelisted domains. 10MB size limit, 30s timeout.

3. parse_closing_disclosure

Parse a Closing Disclosure PDF into MISMO-compliant JSON.

Similar to parse_loan_estimate but for final closing documents.

4. compare_le_cd

Compare Loan Estimate vs Closing Disclosure for TRID compliance.

Input:

{
  "loan_estimate_url": "https://storage.googleapis.com/docs/le.pdf",
  "closing_disclosure_url": "https://storage.googleapis.com/docs/cd.pdf"
}

Output:

{
  "is_compliant": false,
  "violations": [
    {
      "type": "zero_tolerance",
      "fee": "Origination Charges",
      "le_amount": 1500.00,
      "cd_amount": 1600.00,
      "amount_over": 100.00,
      "description": "Origination Charges increased by $100.00"
    }
  ],
  "summary": "✗ NOT COMPLIANT: 1 violation(s) found"
}

📚 Resources

The server provides read-only resources:

• mortgage://schemas/mismo-le - MISMO 3.4 Loan Estimate schema
• mortgage://schemas/mismo-cd - MISMO 3.4 Closing Disclosure schema
• mortgage://glossary/terms - Mortgage terminology definitions

💡 Prompts

Pre-built workflows:

analyze_loan_estimate

Arguments: { "analysis_type": "comprehensive" }

Types: quick, comprehensive, compliance

🔒 Security

Built-in Protections

• ✅ HTTPS only - HTTP URLs are rejected
• ✅ Domain whitelist - Only approved storage domains (prevents SSRF attacks)
• ✅ File size limits - 10MB maximum
• ✅ Timeout protection - 30-second download timeout
• ✅ PDF validation - Checks magic bytes
• ✅ Type safety - All inputs/outputs validated with Pydantic

Allowed Domains

By default:

• storage.googleapis.com
• s3.amazonaws.com
• mortgage-docs.confer.ai

To add more, set ALLOWED_DOMAINS environment variable.

🧪 Development

Run Tests

# Quick test suite
python test_server.py

# Full pytest suite
pytest tests/ -v

Test with MCP Inspector

npm install -g @modelcontextprotocol/inspector
npx @modelcontextprotocol/inspector python server.py

📈 Roadmap

✅ v2.0.0 (Current)

• Modern MCP protocol implementation
• Basic tool definitions with stub data
• Security controls
• Resources and prompts
• Type-safe data models

🚧 v2.1.0 (In Progress)

• Real PDF parsing (AI-powered or PyMuPDF)
• Comprehensive test suite
• Performance optimizations

🔮 v2.2.0 (Planned)

• Streaming support
• Progress notifications
• Background task queue
• Additional mortgage analysis tools

🔄 Migrating from v0.1.0

If upgrading from the old REST API version:

• See [MIGRATION_GUIDE.md](MIGRATION_GUIDE.md) - Step-by-step instructions
• See [MODERNIZATION_SUMMARY.md](MODERNIZATION_SUMMARY.md) - Analysis of changes

Key Changes:

• ❌ Removed FastAPI/HTTP REST API
• ✅ Added MCP protocol (JSON-RPC 2.0 via stdio)
• ✅ Removed API key authentication
• ✅ Added type-safe tool definitions
• ✅ Added resources and prompts

📖 Documentation

• [MCP Specification](https://modelcontextprotocol.io/specification/2025-03-26) - Official protocol spec
• [MIGRATION_GUIDE.md](MIGRATION_GUIDE.md) - Detailed migration instructions
• [MODERNIZATION_SUMMARY.md](MODERNIZATION_SUMMARY.md) - Modernization analysis

🤝 Contributing

We welcome contributions! See CONTRIBUTING.md for guidelines.

📄 License

MIT License - see LICENSE file for details.

🏢 About

Maintained by Confer Solutions

Contact: [email protected]

⭐ Changelog

v2.0.0 (2025-11-16) - Modern MCP Protocol

Major Rewrite: Complete architectural modernization to MCP specification 2025-03-26.

Added:

• MCP protocol support (JSON-RPC 2.0 via stdio)
• Four tools: hello, parse_loan_estimate, parse_closing_disclosure, compare_le_cd
• Resources: MISMO schemas, mortgage glossary
• Prompts: analyze_loan_estimate
• Security: URL validation, SSRF prevention, size limits
• Type safety: Pydantic models

Removed:

• FastAPI/HTTP REST API
• API key authentication
• Rate limiting
• Static JSON configuration

Changed:

• Server: FastAPI → Official MCP SDK
• Transport: HTTP → stdio
• Dependencies: 15+ → 6 core packages

v0.1.0 (2024-04-12) - Initial Release

Deprecated: REST API version. Use v2.0.0+.

Status: ✅ Active Development | 🏗️ Beta | 📦 Production-Ready Core

Last Updated: November 16, 2025