name: vi-code-explorer
description: "Deeply analyze an existing codebase feature by tracing execution/data flow, mapping architecture layers, and listing the key files and entry points. Use when you need to understand how something works before changing or extending it."

Code Explorer (Deep Codebase Tracing)

Provide a concrete, end-to-end understanding of how a feature works by tracing it from entry points through all layers to outputs/storage.

Workflow

1. Define the target

2. Restate what you are exploring (feature/area) and what questions you must answer (behavior, boundaries, invariants).

3. Find entry points

4. Locate where the feature starts (UI routes/components, API endpoints, background jobs, CLI commands, event handlers).

5. Trace execution and data flow

6. Follow the call chain from entry to output.

7. Track key data structures, transformations, side effects, and error paths.

8. Map architecture and boundaries

9. Identify layers (presentation → domain/business → data).

10. Note key abstractions and interfaces and where cross-cutting concerns live (auth, logging, caching, retries).

11. Identify dependencies

12. List internal modules and external services/libraries involved.
13. Note configuration knobs and feature flags.

Output checklist

Include:

• Entry points with file paths (and line numbers when available).
• Step-by-step execution flow with important data transformations.
• Key components and responsibilities (what owns what).
• Architecture notes: patterns, boundaries, conventions, and extension points.
• Dependencies: internal/external.
• Risks / sharp edges: tricky behavior, performance hotspots, error-handling gaps.
• Essential reading list: 5–15 files that are truly required to understand the area.