# Prompt Regression Skill

> Prompt Regression Skill

- Skill: `rogerchappel/prompt-regression-skill` (Agent Skill, multi-file: 9 files)
- Install (CLI): `npx skillmds@latest add rogerchappel/prompt-regression-skill`
- Raw SKILL.md: https://api.skillmd.com/api/skills/rogerchappel/prompt-regression-skill/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: rogerchappel (https://skillmd.com/u/rogerchappel)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/rogerchappel/prompt-regression-skill

---

# Prompt Regression Skill

## When To Use

Use this skill when an agent is reviewing prompt edits, prompt library changes, or saved model-output examples and needs a deterministic preflight before asking for human review.

## Required Inputs

- A JSON file containing regression cases.
- Each case should include `name`, `output`, and optional `expect.required`, `expect.forbidden`, `expect.tone`, and `notes`.

## Tools

- Local filesystem read access.
- Node.js 20 or newer.
- No model API or network access is required.

## Side-Effect Boundaries

This skill is read-only. It must not call model APIs, rewrite prompts, edit fixtures, create PR comments, or update issue trackers without explicit approval.

## Workflow

1. Run `npm run smoke` to verify the bundled fixture.
2. Add or update local regression cases in the target project.
3. Run `node bin/prompt-regression-skill.js <cases.json>`.
4. Review failed cases and risk notes.
5. Include the report summary in the prompt PR or handoff.

## Validation

Run:

```bash
npm run check
npm test
npm run smoke
```