code-explorer

name	code-explorer
description	Survey a codebase area before changing it. Maps file tree, traces dependencies, identifies idioms.
when_to_use	User asks "where is X" or "how does Y work" or before any non-trivial change.

code-explorer

Goal

Build a small, accurate mental model of a codebase area before touching it. Don't modify anything — this skill is read-only.

Process

1. Top-down: read directory listing, identify the entry point (main.*, index.*, app.*).
2. Trace from the entry point: follow imports two or three hops deep, noting which files are infrastructure vs business logic.
3. Read 2-3 sibling files to learn the codebase's idioms — error handling style, naming conventions, test layout.
4. Find the test for the area — tests document expected behavior better than comments.
5. Identify constraints — read any rules/, docs/, or top-level CLAUDE.md/AGENTS.md that affect this area.

Output

Area: <path>
Entry point: <file>:<symbol>
Key files:
  <file>: <one-line role>
  …
Idioms observed:
  - <pattern>
  - <pattern>
Tests:
  <path> — covers <what>
Constraints:
  - <rule or doc>
Open questions (for the user):
  - <…>

Don't

• Don't read more than ~15 files. If you need more, the question is too broad — narrow with the user first.
• Don't write code.
• Don't speculate about behavior you haven't read.