Prompt makes agents map an old codebase before changing anything
A general prompt tells agents like Astra and Opus 5.5 to fully trace dependencies and side effects before editing, with no code changes until the map is manually approved.
If you’re vibe coding on an old repo, paste this before your agent touches a single line. Opus 5.5, GPT-6 Astra, Grok Bot, doesn’t matter. Make it map the codebase first. “Before we change anything, map this entire codebase. Trace every piece of code this task and session will touch, what depends on it, and what breaks if it changes. Flag any dead code, hidden side effects, and literally anything you're guessing about that's not proven by code reads and specific lines. No code edits until I approve the map manually.” Most agent mistakes in legacy code start with skimming. Save this prompt.