What is code-modernization?
code-modernization is a Claude Code mod by anthropics that guided modernization for any legacy codebase: start with /modernize, get an assessment, an interactive map, the business rules mined from the code, and a plan you approve, then an upgrade,. It is listed under Security and has 41,932 GitHub stars.
| Type | Claude code mod |
|---|---|
| Author | anthropics |
| Repository | anthropics/claude-plugins-official |
| Popularity | 41,932 GitHub stars |
| Category | Security |
| Security | Review before installing (72/100) |
| Rank | #47 of 5,272 Claude Code mods; #25 in Security |
| License | Apache-2.0 |
| Last commit | 2026-10-17 |
| Stars this week | +4,241 |
| Hooks | 8 events |
| Sees | every prompt, every tool call |
| Draws on | PromptHint, AbovePrompt, Pane |
Is code-modernization safe to install?
code-modernization scores 72/100 on the MCPMods security check: Review before installing. Things to review: writes files or config; watches every prompt or event. It passed 5 of 8 checks.
Mod footprints come from claude plugin validate, which lists every event a mod hooks and every API call it makes without running it.
| Check | Result |
|---|---|
| No network access | Pass |
| Starts no processes | Pass |
| Writes files or config | Review |
| Doesn't read environment variables | Pass |
| Watches every prompt or event | Review |
| Drives Claude (model calls, prompts) | Note |
| Passes claude plugin validate | Pass |
| Has an open-source license | Pass |
API calls in its code
| Call | What it means |
|---|---|
$.clock.after | |
$.clock.every | |
$.clock.now | |
$.command.register | |
$.fs.exists | reads files |
$.fs.list | reads files |
$.fs.read | reads files |
$.fs.stat | reads files |
$.fs.write | writes files |
$.prompt.fill | writes the prompt box |
$.prompt.submit | drives Claude |
$.store.get | keeps its own state |
$.store.set | keeps its own state |
$.turn.abort | drives Claude |
$.ui.blit | draws interface |
$.ui.close | draws interface |
$.ui.invalidate | draws interface |
$.ui.log | draws interface |
$.ui.open | draws interface |
$.ui.resolve | draws interface |
$.ui.status | draws interface |
$.ui.toast | draws interface |
How do I install code-modernization?
- Check your Claude Code version. Mods need Claude Code 2.1.287 or later and are on by default.
claude --version
- Read its footprint. This lists every event it hooks and every API call it makes, without running it.
git clone https://github.com/anthropics/claude-plugins-official claude plugin validate ./claude-plugins-official/plugins/code-modernization
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add anthropics/claude-plugins-official && claude plugin install code-modernization@claude-plugins-official
Or ask Claude to set it up
Paste this into Claude Code and it installs code-modernization for you:
Install the "code-modernization" Claude Code mod from https://github.com/anthropics/claude-plugins-official/tree/main/plugins/code-modernization. Run claude plugin validate on it first and show me what it can access before you enable it.