Claude Code Subagents: Parallel AI Workers for Complex Projects

Subagents are Claude Code's secret weapon. While most people use Claude Code as a single agent, the real power comes from spawning parallel workers that explore, research, and build simultaneously.

What Are Subagents?

Subagents are independent Claude Code instances spawned from your main session. Each one gets its own context, tools, and conversation. They run in parallel and return results to the main agent.

Think of it like having a team of junior developers. You assign tasks, they work independently, and report back. Except these "juniors" can read your entire codebase and work at machine speed.

How They Work

Claude Code uses the Task tool to spawn subagents. Each subagent:

1. Receives a specific task description
2. Gets access to the filesystem and tools
3. Works independently in its own context
4. Returns results to the main session

You can run multiple subagents simultaneously - they don't block each other.

When to Use Subagents

Codebase exploration - "Search the codebase for all authentication-related code and summarize the patterns." Subagents can scan thousands of files in parallel.

Research tasks - "Look up the latest Next.js 15 migration guide and summarize breaking changes." One subagent researches while you continue building.

Parallel implementation - For independent features, spawn separate subagents for each. Frontend and backend development happening simultaneously.

Code review - Subagents can review code for security issues, performance problems, and pattern consistency.

Real Examples

Example 1: Multi-File Refactor

I needed to rename a component used across 30+ files. Instead of doing it in one long sequence:

1. Spawned a subagent to find all usages
2. The subagent returned a complete map of files and line numbers
3. Main agent made the changes with full context

Example 2: Feature Research

Before implementing OAuth, I spawned two subagents simultaneously:

• One to explore the existing auth setup
• One to research the OAuth library's API

Both returned results in parallel. I had a complete picture in minutes instead of spending time on serial exploration.

Subagent Types

Claude Code offers specialized subagent types:

• Explore - Fast codebase search and analysis
• Plan - Architecture planning and design
• Code reviewer - Security and quality checks
• General purpose - Research and multi-step tasks

Choose the type that matches your task for better results.

Patterns for Orchestration

Fan-out/Fan-in: Spawn multiple subagents for parallel research, collect all results, then synthesize.

Pipeline: Chain subagents where each one's output feeds the next.

Background workers: Spawn subagents in the background for long-running tasks while you continue working.

Limitations

• Subagents have limited context about your main conversation
• Write permissions may require approval
• Cost scales with the number of active agents
• Each subagent starts fresh - no shared memory between them

For the full Claude Code workflow including subagents, see the Claude Code Complete Guide.

Frequently Asked Questions

How many subagents can I run at once?

Do subagents share context with the main agent?

Do subagents cost extra?