code-modernization Plugin
Plugin Claude Code Development Migration & ModernizationClaude Code Customization & WorkflowThe explanation below is AI-generated. Please verify it against the sources.
code-modernization is a Claude Code plugin for modernizing legacy codebases such as COBOL, legacy Java/C++/.NET systems, and monolith web applications. According to the plugin's README, it enforces a fixed sequence of commands — preflight → assess → map → extract-rules → brief → (reimagine | transform | uplift) → harden — because modernization projects tend to fail when teams skip steps. Discovery commands (assess, map, extract-rules) write artifacts to analysis//, and brief synthesizes them into a human-approved modernization plan before any new code is written. Three build methods are offered — transform (cross-stack rewrite), reimagine (greenfield rebuild), and uplift (same-stack version bump) — each producing behavior-equivalence tests. Specialist subagents (legacy-analyst, business-rules-extractor, architecture-critic, security-auditor, test-engineer, version-delta-analyst, scaffolder) support individual steps, and the plugin is configured to never edit the legacy/ directory.
Overview
This is a Claude Code plugin, not a hosted SaaS. It is installed with /plugin install code-modernization@claude-plugins-official and operates on a local legacy codebase placed under legacy//, writing analysis artifacts to analysis// and generated or transformed code to modernized//, per the README.
What you can do with code-modernization
- Run /modernize-preflight to check environment readiness before starting.
- Run /modernize-assess to inventory languages, complexity, tech debt, and security posture (with --portfolio for multiple systems).
- Run /modernize-map to generate a dependency/topology map and an interactive TOPOLOGY.html viewer.
- Run /modernize-extract-rules to mine business rules into Given/When/Then Rule Cards with file:line citations.
- Run /modernize-brief to synthesize discovery artifacts into a Modernization Brief requiring human approval.
- Run /modernize-reimagine for a greenfield rebuild from extracted intent.
- Run /modernize-transform for a surgical cross-stack rewrite of a single module.
- Run /modernize-uplift for a same-stack version bump that preserves existing code.
- Run /modernize-harden for a security pass producing SECURITY_FINDINGS.md and a remediation patch.
- Run /modernize-status for a read-only progress report and next-step suggestion.
Sources
Original description (English)
Modernize legacy codebases (COBOL, legacy Java/C++, monolith web apps) with a structured preflight / assess / map / extract-rules / brief / reimagine / transform / harden workflow, an interactive topology viewer, and specialist review agents
History of code-modernization
- Plugin Added code-modernization