Opi - Learning Extractor

Extract learnings from recent work to improve future Claude sessions. Captures two types:

1. Reactive — What went wrong and how it was fixed (bugs, corrections, failed attempts)
2. Preventive — Reusable patterns that prevent future problems (safe components, conventions, security defaults)

Workflow

Step 1: Gather Sources

# Recent commits (last 20)
git log --oneline -20

# Today's commits with details
git log --since="midnight" --format="%h %s"

# Fix/refactor/security commits
git log --oneline -50 | grep -iE "(fix|korja|refactor|bugfix|secur|safe|harden)"

Also check:

• Current conversation for corrections, discoveries, new patterns
• Recent security reviews or audit results
• New reusable components or utilities created this session

Step 2: Classify Each Finding

For each potential learning, determine the type:

Step 3: Route to Destination

See references/learnings-router.md for the full routing table.

Quick reference:

Step 4: Format Learnings

Reactive fix format:

### [Issue Title]
- **Pattern:** What triggers this mistake
- **Wrong:** ❌ The incorrect approach
- **Right:** ✅ The correct approach
- **Why:** Root cause

Preventive pattern format:

### [Convention Title]
- **Rule:** Always do X when Y
- **Wrong:** ❌ The old/unsafe way
- **Right:** ✅ The new/safe way
- **Why:** What this prevents
- **Since:** date or commit ref

Recent Corrections table row:

| Date | Issue | Fix | Applies To |

Step 5: Propose & Write

1. Present all proposed learnings grouped by destination file
2. User approves/rejects each
3. Write approved learnings to files
4. Commit changes

Learning Quality Criteria

Only propose learnings that are:

• Non-obvious — Claude wouldn't know without being told
• Actionable — Concrete wrong/right examples, not vague advice
• Recurring — Likely to come up again in this codebase
• Preventive OR Corrective — Either prevents future bugs or fixes repeated mistakes

Skip: Typo fixes, one-off configs, project-specific constants, things Claude already knows.

Preventive Patterns to Watch For

When analyzing commits, specifically look for these signals that indicate a preventive learning:

Commands Reference

# Commits since specific date
git log --since="2025-01-10" --oneline

# Commits by pattern
git log --all --oneline | grep -i "fix"

# Show specific commit
git show <hash> --name-only

# Diff for a commit
git diff <hash>^..<hash>

# Security-related commits
git log --oneline -50 | grep -iE "(secur|rls|grant|xss|valid|sanitiz|safe|harden)"