Error Pattern Analysis Skill

Error Pattern Analysis

Analyze errors captured from Claude Code sessions to identify patterns and get actionable insights.

Quick Start

/errors              # Batch analysis of historical error patterns
/debug               # CC 2.1.30 real-time debug for current session

When to Use Which

| Command | Purpose | Scope | |---------|---------|-------| | /errors | Batch analysis of error patterns (last 24h/7d) | Historical patterns | | /debug | Real-time debug of current session state | Current session | | /ork:fix-issue | Full RCA workflow for specific bug | Single issue |

Quick Analysis

# Run batch analysis on last 24h of errors
python .claude/scripts/analyze_errors.py

# Analyze last 7 days
python .claude/scripts/analyze_errors.py --days 7

# Generate markdown report
python .claude/scripts/analyze_errors.py --report

What Gets Captured

The error collector hook captures:

Tool name (Bash, mcp__memory__search_nodes, etc.)
Error message (first 500 chars)
Tool input (command/query that failed)
Timestamp and session ID

Location: .claude/logs/errors.jsonl

Current Error Rules

Check learned patterns that trigger warnings:

cat .claude/rules/error_rules.json | jq '.rules[] | {id, signature, count: .occurrence_count}'

Files

| File | Purpose | |------|---------| | .claude/hooks/posttool/error-collector.sh | Captures errors to JSONL | | .claude/hooks/pretool/bash/error-pattern-warner.sh | Warns before risky commands | | .claude/scripts/analyze_errors.py | Batch pattern analysis | | .claude/rules/error_rules.json | Learned error patterns | | .claude/logs/errors.jsonl | Raw error log |

Common Patterns

Connection Refused / Wrong Port

pattern: ECONNREFUSED|connection refused|ERR_CONNECTION_REFUSED|connect ECONNREFUSED
fix: The port may have changed or the service isn't running.
     1. Check services: portless list (if installed)
     2. Use named URLs: api.localhost:1355 instead of localhost:PORT
     3. Fallback: lsof -iTCP -sTCP:LISTEN -nP | grep -E 'node|python|java'
     4. Install Portless to avoid port guessing: npm i -g portless

pattern: ERR_CONNECTION_RESET|ECONNRESET|socket hang up
fix: Service may have crashed. Check process logs, restart the service,
     and use agent-browser to verify the app is responding:
     agent-browser open "http://myapp.localhost:1355"

PostgreSQL Connection Errors

pattern: role "X" does not exist
fix: Use Docker connection: docker exec -it orchestkit-postgres-dev psql -U orchestkit_user -d orchestkit_dev

pattern: relation "X" does not exist
fix: Check MCP postgres server connection string - may be connected to wrong database

Related Skills

ork:fix-issue: Fix identified errors
debug-investigator: Debug error root causes

Adding New Rules

Rules are auto-generated by analyze_errors.py when patterns repeat 2+ times. For manual rules, edit .claude/rules/error_rules.json:

{
  "id": "custom-001",
  "pattern": "your regex pattern",
  "signature": "human readable signature",
  "tool": "Bash",
  "occurrence_count": 1,
  "fix_suggestion": "How to fix this"
}

Agent Skills: Error Pattern Analysis

Install this agent skill to your local

Skill Files