Claude Code Subagents: What They Are and When to Use Them
Claude Code subagents are specialized helpers that can handle focused work while the main session stays clean.
They are useful when a task has separable research, review, or implementation pieces. They are not magic. If you split the wrong work, you create coordination overhead instead of speed.
Quick picks
- Best use: Focused investigation. Send a subagent to map one subsystem, find usages, or inspect tests.
- Second-best use: Independent review. A review subagent can look for risks without polluting the implementation thread.
- Avoid: Tiny edits. If the task takes one file and five minutes, a subagent is overhead.
- Rule: Give each subagent one job. Specific briefs produce useful summaries.
What subagents are for
Subagents are best when the main Claude Code session needs help understanding a separate slice of the repo. They can investigate, summarize, review, or perform focused work depending on the setup and permissions.
The point is context control. Instead of dumping every file into the main conversation, a subagent can do the messy reading and return the useful summary.
Good subagent tasks
A good subagent task has a clear boundary and a clear return format. If you cannot describe what the subagent should bring back, the task is probably too vague.
- Map the authentication flow and identify files involved.
- Find every use of a deprecated API and group by risk.
- Review this change for accessibility issues only.
- Inspect existing tests and propose the smallest missing coverage.
- Compare two possible implementation paths and recommend one.
Bad subagent tasks
Do not spawn subagents just to feel advanced. Parallel work creates merge risk, duplicate effort, and inconsistent assumptions if the work is not split cleanly.
Avoid subagents for tiny edits, product decisions, vague refactors, or tasks where one shared context is more important than speed.
Copyable prompts
Claude Code subagent research brief
Use a focused research subagent for [AREA]. It should not edit files. It should identify key files, explain the current flow, name risks, and return a concise summary with file references and suggested next steps.Claude Code subagent review brief
Use a focused review subagent for [CHANGE]. Scope: [SCOPE]. Look only for [RISK_TYPE]. Return findings first, with file references and severity. Do not suggest broad refactors.Related Power of AI pages
- Claude Code Best Practices: Use subagents as part of a safe workflow.
- Claude Code Dynamic Workflows: Understand read-plan-edit-verify loops.
- Claude Code Commands: Copyable command-style workflows.
Sources and official references
Related Power of AI pages
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