Advanced Plugin Features (2025) Quick Reference Feature Location Purpose Agent Skills skills//SKILL.md Dynamic knowledge loading Hooks hooks/hooks.json Event automation MCP Servers .mcp.json External integrations Team Config .claude/settings.json Repository plugins Hook Event When Fired Use Case PreToolUse Before tool Validation PostToolUse After tool Testing, linting SessionStart Session begins Logging, setup SessionEnd Session ends Cleanup UserPromptSubmit Prompt submitted Preprocessing PreCompact Before compact State save Notification Notification shown Custom alerts Stop User stops Cleanup SubagentStop Subagent ends Logging Variable Purpose ${CLAUDE_PLUGIN_ROOT} Plugin installation path ${TOOL_INPUT_} Tool input parameters Agent Skills Concept

Skills are dynamically loaded based on task context, enabling:

Unbounded capacity: Knowledge split across files Context efficiency: Only load what's needed Progressive disclosure: Three-tier loading Three-Tier Loading Frontmatter: Loaded at startup (triggers) SKILL.md body: Loaded on activation references/: Loaded when detail needed Structure skills/ └── skill-name/ ├── SKILL.md # Core content ├── references/ # Detailed docs │ └── deep-dive.md ├── examples/ # Working code │ └── example.md └── scripts/ # Utilities └── tool.sh

SKILL.md Format

name: skill-name description: | When to activate this skill. Include: (1) Use case 1 (2) Use case 2 Provides: what it offers

Skill Title

Quick Reference

[Tables, key points]

Core Content

[Essential information - keep lean]

Additional Resources

See references/ for detailed guidance.

Hooks Configuration

Inline in plugin.json:

{ "hooks": { "PostToolUse": [{ "matcher": "Write|Edit", "hooks": [{ "type": "command", "command": "${CLAUDE_PLUGIN_ROOT}/scripts/lint.sh" }] }] } }

Separate hooks.json:

{ "PostToolUse": [{ "matcher": "Write", "hooks": [{ "type": "command", "command": "${CLAUDE_PLUGIN_ROOT}/scripts/format.sh", "timeout": 5000 }] }] }

Matchers Write - File writes Edit - File edits Bash - Shell commands Write|Edit - Multiple tools .* - Any tool (use sparingly) Common Patterns

Auto-test after changes:

{ "PostToolUse": [{ "matcher": "Write|Edit", "hooks": [{ "type": "command", "command": "${CLAUDE_PLUGIN_ROOT}/scripts/run-tests.sh" }] }] }

Validate before Bash:

{ "PreToolUse": [{ "matcher": "Bash", "hooks": [{ "type": "command", "command": "${CLAUDE_PLUGIN_ROOT}/scripts/validate-cmd.sh" }] }] }

MCP Server Integration Configuration { "mcpServers": { "server-name": { "command": "node", "args": ["${CLAUDE_PLUGIN_ROOT}/mcp/server.js"], "env": { "API_KEY": "${API_KEY}" } } } }

External Services { "mcpServers": { "stripe": { "command": "npx", "args": ["-y", "@stripe/mcp-server"], "env": { "STRIPE_API_KEY": "${STRIPE_API_KEY}" } } } }

Repository Configuration Team Distribution

Create .claude/settings.json at repo root:

{ "extraKnownMarketplaces": [ "company/internal-plugins" ], "plugins": { "enabled": [ "deployment-helper@company", "code-standards@company" ] } }

Workflow Maintainer creates .claude/settings.json Team members clone repo Trust folder when prompted Plugins install automatically Best Practices Progressive Disclosure Keep SKILL.md under 500 lines Move details to references/ Use examples/ for working code Reference files with relative paths Hooks Use specific matchers (avoid .*) Set reasonable timeouts Use ${CLAUDE_PLUGIN_ROOT} for paths Test scripts independently MCP Document required env vars Provide setup instructions Use environment variables for secrets Test connection before distribution Additional Resources

For detailed patterns, see:

references/hooks-advanced.md - Complete hook patterns references/mcp-patterns.md - MCP integration examples references/team-distribution.md - Repository configuration examples/hook-scripts.md - Working hook scripts