40 agent types — invoke via the Agent tool, agent() in Workflows, or skills that dispatch them. Set agentType for read-only enforcement on analysis phases.

Shell scripts wired to tool events — zero-overhead on success (exit 0 = silent), auto-killed at timeout, logged on failure.

Model Context Protocol servers extend Claude Code with real-time access to external tools, APIs, and data sources.

Plugins extend Claude Code with new skills, MCP tools, and integrations packaged for one-step install.