Create custom subagents - Claude Code Docs

Subagents are specialized AI assistants that handle specific types of tasks. Use one when a side task would flood your main conversation with search results, logs, or file contents you won't reference again — the subagent does that work in its own context and returns only the summary. Define a custom subagent when you keep spawning the same kind of worker with the same instructions.

Each subagent runs in its own context window with a custom system prompt, specific tool access, and independent permissions. Subagents help you preserve context (keeping exploration and implementation out of the main conversation), enforce constraints (limiting which tools a subagent can use), reuse…