prompt-regressionlisted
Install: claude install-skill chrono-meta/forge-harness
# prompt-regression — Harness Regression Detection
After CLAUDE.md edits, rule changes, or new skill additions, harness behavior can silently regress. This skill runs a lightweight probe suite against the changed assets and compares outputs against saved baselines to surface regressions before they reach production.
> **Scope distinction**
> - harness-doctor: structural completeness (files, links, drift)
> - prompt-regression: **behavioral correctness** — did the change alter expected AI response patterns?
---
## Triggers
- `/prompt-regression`
- "prompt regression", "regression check", "regression test"
- "did my rule change break anything", "test harness changes", "verify harness behavior"
- After significant CLAUDE.md edits or new skill commits
---
## Execution Steps
### Step 1. Identify Changed Assets
```bash
# What changed since last commit (or last N commits)
git diff HEAD~1 --name-only -- CLAUDE.md .claude/ plugins/
```
Classify each changed file:
- `CLAUDE.md` → **core behavior** (high impact)
- `.claude/rules/*.md` → **rule layer** (medium impact)
- `plugins/*/skills/*/SKILL.md` → **skill behavior** (scoped impact)
- `plugins/*/skills/*/SKILL.md` (trigger phrases changed) → **trigger routing** (high impact)
If no changes detected: report "No harness changes since last commit — regression check skipped."
---
### Step 2. Load Probe Suite
Check for custom probes:
```bash
ls .claude/regression/probes.md 2>/dev/null || echo "NO_CUSTOM_PROBES"
```
**If custo