What is tdd-mod?
tdd-mod is a Claude Code mod by koslowskyj that blocks file writes that break Red-Green-Refactor on coding tasks (port of probity's enforceTdd). It is listed under Interface and has 2 GitHub stars.
| Type | Claude code mod |
|---|---|
| Author | koslowskyj |
| Repository | koslowskyj/tdd-mod |
| Popularity | 2 GitHub stars |
| Category | Interface |
| Security | Low risk (84/100) |
| Rank | #1,203 of 5,272 Claude Code mods; #462 in Interface |
| License | MIT |
| Last commit | 2026-10-10 |
| Hooks | 7 events |
| Sees | Bash calls, Edit calls, NotebookEdit calls, Write calls, every prompt, subagent spawns |
| Draws on | nothing |
Is tdd-mod safe to install?
tdd-mod scores 84/100 on the MCPMods security check: Low risk. Things to review: watches every prompt or event. It passed 6 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 no files or config | Pass |
| 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 | |
$.command.register | |
$.fs.exists | reads files |
$.fs.read | reads files |
$.model.complete | drives Claude |
$.session.messages | reads the transcript |
$.session.root | |
$.ui.log | draws interface |
$.ui.status | draws interface |
How do I install tdd-mod?
- 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/koslowskyj/tdd-mod claude plugin validate ./tdd-mod/.
- Install it. Run this in your terminal, then /reload-plugins in an open session.
claude plugin marketplace add koslowskyj/tdd-mod && claude plugin install tdd-mod@tdd-mod
Or ask Claude to set it up
Paste this into Claude Code and it installs tdd-mod for you:
Install the "tdd-mod" Claude Code mod from https://github.com/koslowskyj/tdd-mod. Run claude plugin validate on it first and show me what it can access before you enable it.