Karpathy Guidelines

A preventive thinking discipline for code implementation. Activates before and during code writing to block the most common mistakes LLMs make when generating code.

This is not about performance (that's rob-pike) or debugging (that's systematic-debugging). This is about the act of writing code itself — reading before writing, changing only what's asked, verifying instead of assuming, and defining what "done" means before starting.

Hard Gates

These rules have no exceptions.

1. Read before you write. Do not modify a file you haven't read. Do not modify a function without understanding the callers. Do not modify a module without understanding its role.
2. Scope to the request. Change what was asked. Nothing more. No "while I'm here" improvements, no opportunistic refactoring, no adding features that weren't requested.
3. Verify, don't assume. If you think a function does X, read it. If you think a type has field Y, check it. If you think a test covers scenario Z, find it. Assumptions are the primary source of LLM coding errors.
4. Define success before starting. Before writing any code, state what "done" looks like in concrete, verifiable terms. If you can't define it, you don't understand the task yet.

When To Use