Legacy App Modernization with AI: The MCP Guide
Connect legacy applications to AI agents without putting critical business logic in the hands of an LLM.
Your business wants AI capabilities now. Your architecture team knows a full rewrite could take years. Meanwhile, essential workflows remain locked inside VB6, PowerBuilder, and other legacy systems.
This guide explains how to use the strangler fig pattern to expose proven legacy functionality through the Model Context Protocol (MCP). Your AI agent manages the conversation. Your existing code continues to execute the business rules.
What You’ll Learn
- Triage and isolate the application. Identify critical business logic and separate it from the legacy UI without disrupting production.
- Build a .NET interoperability bridge. Wrap 32-bit COM components in modern .NET services that connect securely to cloud applications.
- Integrate MCP and govern agent access. Use strict JSON schemas, Entra ID RBAC, and controlled tool routing to limit what agents can access and execute.
- Modernize incrementally. Use shadow routing and .NET Aspire to replace legacy components with Blazor and Azure services without a high-risk, all-at-once rewrite.
Download the guide to give AI agents secure access to the business logic you already trust.
