Code Reviewer Subagent

Requires: Claude Code installed · A project with a git repo

1. 1

   Create the agents directory

   Subagents live in `.claude/agents/` at your project root (or `~/.claude/agents/` for all projects).

   shellCopy

   mkdir -p .claude/agents

2. 2

   Define the reviewer

   Create `code-reviewer.md` with frontmatter and a focused system prompt.

   configCopy

   ---
   name: code-reviewer
   description: Reviews the current diff for bugs, security, and style. Use before committing.
   tools: Read, Grep, Bash
   ---
   
   You are a meticulous senior code reviewer. Review ONLY the changed lines.
   Report issues grouped by severity (blocker, warning, nit) with file:line refs.
   Never rewrite the code — describe the fix. Praise nothing; be terse.

3. 3

   Invoke it

   Ask Claude Code to use it by name, or let it auto-delegate when the description matches.

   configCopy

   > use the code-reviewer subagent on my staged changes

You've finished a feature and want a review before committing.

What to expect: The subagent reads the diff in its own context and returns a severity-grouped list of issues with file:line references, without touching your main conversation.

• Stage only what you want reviewed (`git add -p`) so the scope is tight.
• Ask it to also propose test cases for the risky paths.