What is lexi?
lexi is a Claude Code mod by savinofiore that test-first workflow for coding agents, without the spec ceremony. A PreToolUse hook keeps source edits behind a mirror test and protects existing assertions; the flow drives one vertical. It is listed under Cost & usage and has 4 GitHub stars.
| Type | Claude code mod |
|---|---|
| Author | savinofiore |
| Repository | savinofiore/lexi |
| Popularity | 4 GitHub stars |
| Category | Cost & usage |
| Security | Review before installing (60/100) |
| Rank | #754 of 5,272 Claude Code mods; #143 in Cost & usage |
| License | MIT |
| Last commit | 2026-10-11 |
| Hooks | 11 events |
| Sees | compaction, every prompt, every tool call, subagent spawns |
| Draws on | AbovePrompt, Pane |
Is lexi safe to install?
lexi scores 60/100 on the MCPMods security check: Review before installing. Things to review: sends data over the network; reads environment variables; watches every prompt or event. It passed 4 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 |
|---|---|
| Sends data over the network | Review |
| Starts no processes | Pass |
| Writes no files or config | Pass |
| Reads environment variables | Review |
| Watches every prompt or event | Review |
| Doesn't drive Claude | Pass |
| Validator reported problems | Note |
| Has an open-source license | Pass |
API calls in its code
| Call | What it means |
|---|---|
$.clock.after | |
$.clock.now | |
$.clock.sleep | |
$.command.register | |
$.env.get | reads env vars |
$.fs.read | reads files |
$.http.fetch | network requests |
$.session.model | |
$.state.get | |
$.state.set | |
$.ui.log | draws interface |
$.ui.open | draws interface |
$.ui.resolve | draws interface |
$.ui.status | draws interface |
$.ui.toast | draws interface |
How do I install lexi?
- 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/savinofiore/lexi claude plugin validate ./lexi/.
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add savinofiore/lexi && claude plugin install lexi@lexi
Or ask Claude to set it up
Paste this into Claude Code and it installs lexi for you:
Install the "lexi" Claude Code mod from https://github.com/savinofiore/lexi. Run claude plugin validate on it first and show me what it can access before you enable it.