Claude Code Debug

Troubleshoot extensions, hooks, and unexpected behavior.

Quick Diagnostics

# Enable debug mode
claude --debug

# Check loaded extensions
/hooks        # View registered hooks
/agents       # View available agents
/memory       # View loaded memory files
/config       # View current configuration

Common Issues

Symptom	Quick Check
Skill not activating	Verify description has trigger keywords
Hook not running	Check chmod +x, run /hooks
Agent not delegating	Add "Use proactively" to description
MCP connection fails	Test server manually with npx
Permission denied	Check settings.json allow rules

Debug Mode Output

claude --debug
# Shows:
# - Hook execution and errors
# - Skill loading status
# - Subagent invocations
# - Tool permission decisions
# - MCP server connections

Quick Fixes

Skill Not Loading

# Check structure
ls -la .claude/skills/my-skill/
# Must have: SKILL.md

# Verify YAML frontmatter
head -10 .claude/skills/my-skill/SKILL.md
# Must start/end with ---

# Check name matches directory
grep "^name:" .claude/skills/my-skill/SKILL.md

Hook Not Executing

# Make executable
chmod +x .claude/hooks/my-hook.sh

# Test manually
echo '{"tool_name":"Bash"}' | .claude/hooks/my-hook.sh
echo $?  # Check exit code

# Verify JSON syntax
jq '.' ~/.claude/settings.json

Agent Not Being Used

# Check file location
ls ~/.claude/agents/
ls .claude/agents/

# Verify description includes "Use for:" or "Use proactively"
grep -i "use" agents/my-agent.md | head -5

# Explicitly request
# "Use the my-agent agent to analyze this"

Validation

# Run all validations
just test

# YAML validation only
just validate-yaml

# Name matching only
just validate-names

Official Documentation

• https://code.claude.com/docs/en/hooks - Hooks reference
• https://code.claude.com/docs/en/skills - Skills reference
• https://code.claude.com/docs/en/sub-agents - Custom subagents
• https://code.claude.com/docs/en/settings - Settings configuration

Additional Resources

• ./references/common-issues.md - Issue → Solution lookup table
• ./references/debug-commands.md - All inspection commands
• ./references/troubleshooting-flow.md - Decision tree

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See Also: claude-code-hooks for hook debugging, claude-code-templates for correct structure