devilsnerve/codex-modernize
Modernize legacy systems with evidence-backed discovery, architecture maps, business rules, behavior tests, and controlled migrations.
Assess legacy code or a portfolio of systems for architecture, complexity, debt, security, and modernization options. Produces evidence-backed assessment artifacts, not implementation changes.
Synthesize legacy discovery into a phased modernization brief with architecture, behavior contracts, entry criteria, and approval scope. Use to plan a rewrite, rebuild, or version uplift.
Extract and verify legacy business rules as cited Given/When/Then Rule Cards and a data-object catalog. Use before rewrites or behavior-equivalence work.
Audit a legacy system for vulnerabilities and produce reviewed remediation patches without editing the legacy source. Includes credential quarantine and source verification of security findings.
Map legacy dependencies, data lineage, entry points, and persona flows into topology.json, an offline interactive architecture viewer, and small Mermaid diagrams.
Check a legacy system's toolchains, source completeness, build infrastructure, and scope boundary before modernization. Use for readiness checks; report gaps without changing legacy source.
Rebuild a legacy system from extracted business intent: specification, reviewed target architecture, service scaffolds, acceptance tests, and an AGENTS.md handoff.
Report modernization progress, stale artifacts, approval gaps, and secret-file hygiene without changing files. Use to resume a modernization effort and identify the next useful step.
Rewrite one legacy module into a different target stack, using characterization tests and behavior-equivalence evidence. Use for cross-stack transformations, not same-stack version upgrades.
Upgrade a legacy system to a newer version of the same stack while preserving structure. Supports catalog-only analysis, baseline tests, a pilot playbook, dependency-ordered migration, and equivalence checks.