code-modernization

How to start

1. Paste the command into Claude Code and press Enter.
2. Restart Claude Code so the plugin loads.
3. Try it: type /modernize-assess or /modernize-brief.

What it adds

13 commands · 8 agents · 5 hooks

Commands Type it in Claude Code

• /modernize-assessWhat am I dealing with? Inventory, complexity, debt, security and a recommended modernization pattern
• /modernize-briefWrite the phased Modernization Brief — the plan a steering committee approves and the build commands execute against
• /modernize-extract-rulesMine the business rules out of the code into testable Given/When/Then rule cards with file:line citations
• /modernize-hardenSecurity scan of the legacy system with a reviewable remediation patch (OWASP, CWE, CVEs, secrets, injection)
• /modernize-mapShow me the structure — dependencies, data flow, entry points and business flows, as an interactive map
• /modernize-preflightRun this first — checks the environment, records where the code lives, and says what to fix before anything else runs
• /modernize-reimagineRebuild the system from its extracted intent on a new architecture, with two human checkpoints
• /modernize-reviewConfirm or correct the business rules that need a person's judgement; the plan and the build read your answers
• /modernize-statusWhere am I? Progress, what is stale, and the exact next command to run — start here when unsure
• /modernize-transformRewrite one legacy module in the target stack, with tests that prove it behaves the same
• /modernize-upliftSame-stack version uplift (e.g. .NET Framework 4.8 to .NET 8, Java 8 to 17) — keep the code, fix the version deltas, prove nothing changed
• /modernize-verifyProve the modernized code behaves like the legacy, with an independent re-check and one verdict per module
• …and 1 more in the source.

Agents Claude hands work to these

• architecture-criticReviews proposed target architectures and transformed code against modern best practice. Adversarial — looks for over-engineering, missed requirements, and sim…
• business-rules-extractorMines domain logic, calculations, validations, and policies from legacy code into testable Given/When/Then specifications. Use when you need to separate "what…
• legacy-analystDeep-reads legacy codebases (COBOL, Java, .NET, Node, anything) to build structural and behavioral understanding. Use for discovery, dependency mapping, dead-c…
• scaffolderScaffolds one service of a reimagined system from the approved architecture and spec — project skeleton, domain model, API stubs, executable acceptance tests.…
• security-auditorAdversarial security reviewer — OWASP Top 10, CWE, dependency CVEs, secrets, injection. Use for security debt scanning and pre-modernization hardening.
• test-engineerWrites characterization, contract, and equivalence tests that pin down legacy behavior so transformation can be proven correct. Use before any rewrite.
• uplift-migratorMigrates ONE project/module of an in-flight same-stack version uplift by applying a proven pilot playbook — minimal diff, then runs that unit's real build to p…
• version-delta-analystIdentifies the breaking changes between two versions of the SAME stack (e.g. .NET Framework 4.8 → .NET 8, Java 8 → 17/21, Spring Boot 2 → 3) that actually bite…

Hooks Run on their own at these moments

• UserPromptSubmitWhen you send a message.
• StopWhen Claude finishes a reply.
• SessionStartWhen a session starts.
• PostToolUseFailureA Claude Code hook event.
• StopFailureA Claude Code hook event.

Read from the plugin's own files in anthropics/claude-plugins-official, 26 Oct 2026.

What it needs

No keys or settings: its files ask for none.