System Prompts and Configuration Files (CLAUDE.md) for Legacy System Modernization with Coding Agents

This repository contains the three CLAUDE.md configuration and prompt files used to instruct the Claude Code AI agent in the case study "Legacy System Modernization with Coding Agents: A Case Study". These files were employed to guide the autonomous migration of 12 features from a legacy corporate ERP system, originally implemented in Visual Basic 6 (VB6), to a target architecture in C# .NET 10. According to the single-pass generation strategy methodology, the working directory for each feature was configured with the following structure: Root CLAUDE.md: Placed in the directory root, containing general instructions for the agent such as the migration's goal, functional scope, methodology, and coding conventions. Legacy Version CLAUDE.md: Placed in the -legacy-version subdirectory, serving as a reference by describing the legacy VB6 source organization, artifacts to be migrated, and legacy coding patterns. Migration Version CLAUDE.md: Placed in the -migration-version subdirectory, detailing specific conventions for the C# .NET 10 structure, including the expected layered architecture (Controllers, Services, Repositories, Data, Models).