File	Purpose
`CLAUDE.md`	Project memory, read at session start
`.claude/settings.json`	Hook configuration, permissions
`.claude/settings.local.json`	Personal overrides (gitignored)
`.mcp.json`	MCP server configuration
`.lsp.json`	LSP server configuration

Hooks (13 Types)

Hook	Trigger
`SessionStart`	Session begins
`SessionEnd`	Session ends
`UserPromptSubmit`	User submits prompt
`PreToolUse`	Before tool execution
`PostToolUse`	After tool succeeds
`PostToolUseFailure`	After tool fails
`PermissionRequest`	Permission requested
`Notification`	Notification sent
`Stop`	Agent stopping
`SubagentStart`	Subagent begins
`SubagentStop`	Subagent completes
`PreCompact`	Before context compaction
`Setup`	Repository init/maintenance

Hook Types

command - Execute shell command
prompt - Inject prompt (Stop/SubagentStop only)

Hook Response Format

{
  "continue": true,
  "stopReason": "string",
  "systemMessage": "string",
  "hookSpecificOutput": {
    "hookEventName": "PreToolUse",
    "permissionDecision": "allow|deny|ask"
  }
}

Skills

Required Frontmatter

name - Lowercase, hyphens, max 64 chars
description - When to use, max 1024 chars

Optional Frontmatter

allowed-tools - Tools allowed without permission
model - Specific model to use
context: fork - Isolated sub-agent context
agent - Agent type for fork context
hooks - Lifecycle hooks
user-invocable - Slash command visibility

Subagents

Required Frontmatter

name - Lowercase with hyphens
description - When to delegate

Optional Frontmatter

tools - Available tools
disallowedTools - Denied tools
model - sonnet, opus, haiku, inherit
permissionMode - default, acceptEdits, dontAsk, bypassPermissions, plan
skills - Skills to load
hooks - Lifecycle hooks

Built-in Agents

Explore - Fast read-only (Haiku)
Plan - Research for planning
general-purpose - Complex tasks
Bash - Terminal commands

Plugins

Structure

plugin/
├── .claude-plugin/plugin.json
├── commands/
├── agents/
├── skills/
├── hooks/hooks.json
├── .mcp.json
└── .lsp.json

Permissions

{
  "permissions": {
    "allow": ["Bash(git diff:*)"],
    "ask": ["Bash(git push:*)"],
    "deny": ["Read(./.env)"]
  }
}

MCP Servers

{
  "mcpServers": {
    "name": {
      "command": "npx",
      "args": ["-y", "@package/name"],
      "env": {}
    }
  }
}

Last verified: January 2026

npx skills add https://smithery.ai