Claude Code Skills

Custom skills for Claude Code.

Skills

/rca — Root Cause Analysis

A structured debugging workflow that guides Claude through systematic issue investigation instead of jumping to fixes.

Flow: INTAKE → TRIAGE → REPRODUCE → HYPOTHESIZE → INVESTIGATE → FIX → VERIFY → CLOSE

• Bayesian-style hypothesis scoring (20/40/60/80) with evidence-based updates
• Severity triage (BLEEDING / DEGRADED / STABLE) to prioritize mitigation vs. investigation
• Loop-back protection — if a fix fails, it returns to investigation instead of thrashing
• TDD-aligned fix phase: write failing test, verify red, fix, verify green
• Resumable state via /rca --resume

Usage

There are two ways to trigger the skill:

1. Slash command

Type /rca directly in your Claude Code prompt. You can optionally pass context or flags:

Command	What it does
/rca	Scans the current conversation for errors and asks what you want to investigate
/rca <description>	Starts an investigation with the context you provide (error messages, stack traces, symptoms)
/rca --resume	Picks up a previous investigation from where it left off

2. Natural language

You don't need the slash command — just describe the problem and Claude will activate the skill automatically. Examples:

• "My tests are passing locally but failing in CI"
• "Users are getting 502s on the /api/checkout endpoint"
• "The build broke after the last merge, can you figure out why?"
• "This function is returning null but I don't know why"

The skill triggers whenever Claude detects something is broken, failing, or behaving unexpectedly. The slash command gives you more control (e.g., --resume), but plain English works for starting a fresh investigation.

What to expect

Once activated, Claude will:

1. Triage the severity — is this actively hurting production, or a stable dev issue?
2. Reproduce the error by observing actual output (not just reading code)
3. Generate hypotheses with confidence scores (20/40/60/80)
4. Investigate each hypothesis, updating scores as evidence confirms or eliminates them
5. Fix the root cause with a failing test first, then a minimal fix
6. Verify by running the full test suite — no "should work now" claims without proof
7. Close with a commit linking the root cause and evidence chain

At each phase, Claude shows a hypothesis scoreboard so you can see what's being considered and why:

-- RCA Hypotheses ----------------------------------------
  H1-DbPool       ########.. 80 ^  <- connection timeout in logs
  H2-AuthMW       ##........ 20 v  <- middleware unchanged since March
  H3-RaceCondition ####...... 40 -> <- concurrent requests untested
----------------------------------------------------------

Installation

Copy any skill directory into your Claude Code skills folder:

# Clone the repo
git clone https://github.com/MP2EZ/claude-code-skills.git

# Copy the rca skill
cp -r claude-code-skills/rca ~/.claude/skills/rca

Then use /rca or describe a problem in any Claude Code conversation.

License

MIT