The definitive reference skill for Claude Code's entire extensibility platform. This skill covers every feature area — from plugins and hooks to channels, subagents, MCP servers, scheduled tasks, and headless automation. When a user asks how to build, configure, debug, or extend Claude Code, this skill provides authoritative guidance grounded in the official documentation.
Documentation Index
Fetch the complete documentation index at: https://code.claude.com/docs/llms.txt
Use this file to discover all available pages before exploring further.
Reference Library
27 reference documents covering every Claude Code feature. Read the relevant reference(s) before answering any question.
Extensibility & Plugins
| Reference |
What It Covers |
| plugins.md |
Creating plugins — manifest, agents, skills, hooks, commands, settings |
| plugins-reference.md |
Plugin spec — plugin.json schema, variable resolution, file structure |
| plugin-marketplaces.md |
Creating and distributing plugin marketplaces |
| discover-plugins.md |
Discovering and installing prebuilt plugins |
| skills.md |
Extending Claude with skills — SKILL.md format, frontmatter, scripts |
| sub-agents.md |
Creating custom subagents — agent .md files, model routing, tools |
Hooks & Automation
| Reference |
What It Covers |
| hooks-guide.md |
Hooks walkthrough — setup, common patterns, prompt/agent hooks |
| hooks-ref.md |
Hooks reference — all 22 events, 4 handler types, input schemas, decision control |
| scheduled-tasks.md |
Running prompts on a schedule (cron-style) |
| channels.md |
Pushing events into a running session |
| channels-reference.md |
Channels API reference — event types, protocols |
Multi-Session & Programmatic
| Reference |
What It Covers |
| agent-teams.md |
Orchestrating teams of Claude Code sessions |
| headless.md |
Running Claude Code programmatically (CI, scripts, pipelines) |
Configuration & Security
| Reference |
What It Covers |
| settings.md |
All Claude Code settings — global, project, plugin scopes |
| permissions.md |
Permission modes, allow/deny lists, tool-level control |
| sandboxing.md |
Sandbox environments — Docker, macOS sandbox, network isolation |
| model-config.md |
Model selection, routing, provider configuration |
| network-config.md |
Enterprise network — proxies, certificates, firewall rules |
| llm-gateway.md |
LLM gateway configuration for enterprise deployments |
Tools & Interface
| Reference |
What It Covers |
| tools-reference.md |
Built-in tools — Read, Write, Edit, Bash, Glob, Grep, Agent, etc. |
| mcp.md |
Connecting Claude Code to external tools via MCP servers |
| keybindings.md |
Customizing keyboard shortcuts |
| statusline.md |
Customizing the status line display |
| output-styles.md |
Output formatting and style configuration |
| terminal-config.md |
Terminal setup optimization |
| voice-dictation.md |
Voice input configuration |
| troubleshooting.md |
Common issues, diagnostics, and fixes |
Workflow
- Identify the topic — Parse the user's question to determine which feature area(s) are involved
- Read references — Load the relevant reference file(s) from the table above. For cross-cutting questions, read multiple references.
- Synthesize — Combine reference material with the user's specific context (their project structure, existing config, goals)
- Provide guidance — Give a concrete, actionable answer with code examples. Always cite which reference the guidance comes from.
- Verify — If the user is building something (plugin, hook, skill), validate it against the spec in the reference docs
Topic Routing
| User Asks About |
Read These References |
| Building a plugin |
plugins.md, plugins-reference.md |
| Publishing to marketplace |
plugin-marketplaces.md, discover-plugins.md |
| Writing a skill |
skills.md, plugins.md |
| Creating an agent |
sub-agents.md, plugins.md |
| Setting up hooks |
hooks-guide.md, hooks-ref.md |
| Hook events / types |
hooks-ref.md |
| MCP servers |
mcp.md |
| Permissions / security |
permissions.md, sandboxing.md |
| Settings config |
settings.md |
| Running headless / CI |
headless.md |
| Agent teams / multi-session |
agent-teams.md, channels.md |
| Channels / events |
channels.md, channels-reference.md |
| Scheduled / cron tasks |
scheduled-tasks.md |
| Model selection |
model-config.md |
| Enterprise / network |
network-config.md, llm-gateway.md |
| Keyboard shortcuts |
keybindings.md |
| Status line |
statusline.md |
| Output formatting |
output-styles.md |
| Terminal setup |
terminal-config.md |
| Voice input |
voice-dictation.md |
| Something broken |
troubleshooting.md |
| Built-in tools |
tools-reference.md |
Key Concepts
The 4 Hook Types
- command — Runs a shell command. Exit code 0 = allow, 2 = block.
- http — POSTs JSON to a URL. Response body controls decision.
- prompt — Single-turn LLM judgment. Sends prompt +
$ARGUMENTS to Claude for yes/no.
- agent — Multi-turn subagent with Read/Grep/Glob tools. Full reasoning for complex checks.
The 22 Hook Events
SessionStart, UserPromptSubmit, PreToolUse, PermissionRequest, PostToolUse, PostToolUseFailure, Notification, SubagentStart, SubagentStop, Stop, StopFailure, TeammateIdle, TaskCompleted, InstructionsLoaded, ConfigChange, WorktreeCreate, WorktreeRemove, PreCompact, PostCompact, Elicitation, ElicitationResult, SessionEnd
Plugin Variables
| Variable |
Resolves To |
${CLAUDE_PLUGIN_ROOT} |
Plugin's root directory |
${CLAUDE_PLUGIN_DATA} |
Plugin's data/output directory |
${CLAUDE_SKILL_DIR} |
Current skill's directory |
Plugin File Structure
plugin-name/
├── .claude-plugin/plugin.json ← Manifest (required)
├── agents/*.md ← Role definitions
├── skills/*/SKILL.md ← Workflow definitions
├── commands/*.md ← Entry points
├── context/*.md ← Shared context
├── hooks/hooks.json ← Hook definitions
└── settings.json ← Plugin settings
After this skill
- Configuration question answered → apply via update-config skill if settings.json change needed
- Keybinding question answered → apply via keybindings-help skill
- Hook setup needed → update-config skill handles all hook configuration
1---2name: claude-code3description: Comprehensive Claude Code knowledge base — plugins, hooks, skills, agents, MCP, channels, headless mode, permissions, settings, and all extensibility features. Use when building, configuring, debugging, or extending Claude Code.4---56The definitive reference skill for Claude Code's entire extensibility platform. This skill covers every feature area — from plugins and hooks to channels, subagents, MCP servers, scheduled tasks, and headless automation. When a user asks how to build, configure, debug, or extend Claude Code, this skill provides authoritative guidance grounded in the official documentation.78> ## Documentation Index9> Fetch the complete documentation index at: https://code.claude.com/docs/llms.txt10> Use this file to discover all available pages before exploring further.1112## Reference Library131427 reference documents covering every Claude Code feature. Read the relevant reference(s) before answering any question.1516### Extensibility & Plugins17| Reference | What It Covers |18|-----------|---------------|19| [plugins.md](${CLAUDE_SKILL_DIR}/references/plugins.md) | Creating plugins — manifest, agents, skills, hooks, commands, settings |20| [plugins-reference.md](${CLAUDE_SKILL_DIR}/references/plugins-reference.md) | Plugin spec — plugin.json schema, variable resolution, file structure |21| [plugin-marketplaces.md](${CLAUDE_SKILL_DIR}/references/plugin-marketplaces.md) | Creating and distributing plugin marketplaces |22| [discover-plugins.md](${CLAUDE_SKILL_DIR}/references/discover-plugins.md) | Discovering and installing prebuilt plugins |23| [skills.md](${CLAUDE_SKILL_DIR}/references/skills.md) | Extending Claude with skills — SKILL.md format, frontmatter, scripts |24| [sub-agents.md](${CLAUDE_SKILL_DIR}/references/sub-agents.md) | Creating custom subagents — agent .md files, model routing, tools |2526### Hooks & Automation27| Reference | What It Covers |28|-----------|---------------|29| [hooks-guide.md](${CLAUDE_SKILL_DIR}/references/hooks-guide.md) | Hooks walkthrough — setup, common patterns, prompt/agent hooks |30| [hooks-ref.md](${CLAUDE_SKILL_DIR}/references/hooks-ref.md) | Hooks reference — all 22 events, 4 handler types, input schemas, decision control |31| [scheduled-tasks.md](${CLAUDE_SKILL_DIR}/references/scheduled-tasks.md) | Running prompts on a schedule (cron-style) |32| [channels.md](${CLAUDE_SKILL_DIR}/references/channels.md) | Pushing events into a running session |33| [channels-reference.md](${CLAUDE_SKILL_DIR}/references/channels-reference.md) | Channels API reference — event types, protocols |3435### Multi-Session & Programmatic36| Reference | What It Covers |37|-----------|---------------|38| [agent-teams.md](${CLAUDE_SKILL_DIR}/references/agent-teams.md) | Orchestrating teams of Claude Code sessions |39| [headless.md](${CLAUDE_SKILL_DIR}/references/headless.md) | Running Claude Code programmatically (CI, scripts, pipelines) |4041### Configuration & Security42| Reference | What It Covers |43|-----------|---------------|44| [settings.md](${CLAUDE_SKILL_DIR}/references/settings.md) | All Claude Code settings — global, project, plugin scopes |45| [permissions.md](${CLAUDE_SKILL_DIR}/references/permissions.md) | Permission modes, allow/deny lists, tool-level control |46| [sandboxing.md](${CLAUDE_SKILL_DIR}/references/sandboxing.md) | Sandbox environments — Docker, macOS sandbox, network isolation |47| [model-config.md](${CLAUDE_SKILL_DIR}/references/model-config.md) | Model selection, routing, provider configuration |48| [network-config.md](${CLAUDE_SKILL_DIR}/references/network-config.md) | Enterprise network — proxies, certificates, firewall rules |49| [llm-gateway.md](${CLAUDE_SKILL_DIR}/references/llm-gateway.md) | LLM gateway configuration for enterprise deployments |5051### Tools & Interface52| Reference | What It Covers |53|-----------|---------------|54| [tools-reference.md](${CLAUDE_SKILL_DIR}/references/tools-reference.md) | Built-in tools — Read, Write, Edit, Bash, Glob, Grep, Agent, etc. |55| [mcp.md](${CLAUDE_SKILL_DIR}/references/mcp.md) | Connecting Claude Code to external tools via MCP servers |56| [keybindings.md](${CLAUDE_SKILL_DIR}/references/keybindings.md) | Customizing keyboard shortcuts |57| [statusline.md](${CLAUDE_SKILL_DIR}/references/statusline.md) | Customizing the status line display |58| [output-styles.md](${CLAUDE_SKILL_DIR}/references/output-styles.md) | Output formatting and style configuration |59| [terminal-config.md](${CLAUDE_SKILL_DIR}/references/terminal-config.md) | Terminal setup optimization |60| [voice-dictation.md](${CLAUDE_SKILL_DIR}/references/voice-dictation.md) | Voice input configuration |61| [troubleshooting.md](${CLAUDE_SKILL_DIR}/references/troubleshooting.md) | Common issues, diagnostics, and fixes |6263## Workflow64651. **Identify the topic** — Parse the user's question to determine which feature area(s) are involved662. **Read references** — Load the relevant reference file(s) from the table above. For cross-cutting questions, read multiple references.673. **Synthesize** — Combine reference material with the user's specific context (their project structure, existing config, goals)684. **Provide guidance** — Give a concrete, actionable answer with code examples. Always cite which reference the guidance comes from.695. **Verify** — If the user is building something (plugin, hook, skill), validate it against the spec in the reference docs7071## Topic Routing7273| User Asks About | Read These References |74|-----------------|---------------------|75| Building a plugin | plugins.md, plugins-reference.md |76| Publishing to marketplace | plugin-marketplaces.md, discover-plugins.md |77| Writing a skill | skills.md, plugins.md |78| Creating an agent | sub-agents.md, plugins.md |79| Setting up hooks | hooks-guide.md, hooks-ref.md |80| Hook events / types | hooks-ref.md |81| MCP servers | mcp.md |82| Permissions / security | permissions.md, sandboxing.md |83| Settings config | settings.md |84| Running headless / CI | headless.md |85| Agent teams / multi-session | agent-teams.md, channels.md |86| Channels / events | channels.md, channels-reference.md |87| Scheduled / cron tasks | scheduled-tasks.md |88| Model selection | model-config.md |89| Enterprise / network | network-config.md, llm-gateway.md |90| Keyboard shortcuts | keybindings.md |91| Status line | statusline.md |92| Output formatting | output-styles.md |93| Terminal setup | terminal-config.md |94| Voice input | voice-dictation.md |95| Something broken | troubleshooting.md |96| Built-in tools | tools-reference.md |9798## Key Concepts99100### The 4 Hook Types101- **command** — Runs a shell command. Exit code 0 = allow, 2 = block.102- **http** — POSTs JSON to a URL. Response body controls decision.103- **prompt** — Single-turn LLM judgment. Sends prompt + `$ARGUMENTS` to Claude for yes/no.104- **agent** — Multi-turn subagent with Read/Grep/Glob tools. Full reasoning for complex checks.105106### The 22 Hook Events107SessionStart, UserPromptSubmit, PreToolUse, PermissionRequest, PostToolUse, PostToolUseFailure, Notification, SubagentStart, SubagentStop, Stop, StopFailure, TeammateIdle, TaskCompleted, InstructionsLoaded, ConfigChange, WorktreeCreate, WorktreeRemove, PreCompact, PostCompact, Elicitation, ElicitationResult, SessionEnd108109### Plugin Variables110| Variable | Resolves To |111|----------|------------|112| `${CLAUDE_PLUGIN_ROOT}` | Plugin's root directory |113| `${CLAUDE_PLUGIN_DATA}` | Plugin's data/output directory |114| `${CLAUDE_SKILL_DIR}` | Current skill's directory |115116### Plugin File Structure117```118plugin-name/119├── .claude-plugin/plugin.json ← Manifest (required)120├── agents/*.md ← Role definitions121├── skills/*/SKILL.md ← Workflow definitions122├── commands/*.md ← Entry points123├── context/*.md ← Shared context124├── hooks/hooks.json ← Hook definitions125└── settings.json ← Plugin settings126```127128## After this skill129130- **Configuration question answered** → apply via **update-config** skill if settings.json change needed131- **Keybinding question answered** → apply via **keybindings-help** skill132- **Hook setup needed** → **update-config** skill handles all hook configuration
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