Claude Code — Field Guide

Skills worth knowing

| Skill | When to use | |---|---| | /plan | Any task touching more than 1 file or with unclear scope | | /wrap-up | End of every session — saves context to memory | | /mem-search | Find past decisions, bugs fixed, context from earlier sessions | | /commit | Structured commits with co-author tag | | /resume | Start of session — loads recent context |

CLAUDE.md patterns that work

Rules need to be specific. Bad:

Always be careful with the database.

Good:

Before running any DELETE query, confirm the WHERE clause with the user.
Never use `DROP TABLE` without explicit approval.

Organize by domain. Keep it short — Claude reads the whole file every session. If it's getting long, split into rules/ subdirectories and @import them.

Hook patterns

Hooks run shell commands on Claude Code events. Set them in settings.json.

{
  "hooks": {
    "PostToolUse": [{
      "matcher": "Write|Edit",
      "hooks": [{ "type": "command", "command": "echo 'File edited' >> ~/claude-log.txt" }]
    }],
    "Stop": [{
      "hooks": [{ "type": "command", "command": "claude /wrap-up" }]
    }]
  }
}

Most useful hooks:

• PreToolUse — validate before risky Bash commands. Block rm -rf, DROP TABLE, force pushes.
• PostToolUse — auto-save, auto-format, trigger tests after edits.
• Stop — auto wrap-up every session. Never lose context again.

Agent routing

| Task size | Approach | |---|---| | 1 file, clear scope | Inline — no agent | | 2–5 files, defined task | Agent tool with sonnet subagent | | Cross-domain, architectural | orchestrator — delegates to specialists |

The orchestrator is expensive. Don't call it for simple tasks. Don't do complex tasks inline without it.

Memory system

Session memory lives in Pinecone via the mcp__memory-system__ tools:

• ingest_file — index a file or document into memory
• search_pinecone — semantic search across all past sessions
• search_wiki — search the structured knowledge base
• update_wiki_page — write persistent facts to the wiki

The wiki is for things that are always true. Pinecone is for things that happened. Know the difference.