| name | karpathy-modified-guidelines |
| description | Behavioral guidelines to reduce common LLM coding mistakes by emphasizing thinking before coding, simplicity, surgical changes, and goal-driven execution. Use when implementing features, fixing bugs, refactoring code, or performing any coding task. |
Karpathy Guidelines
Behavioral guidelines to reduce common LLM coding mistakes. Apply these principles to all coding tasks.
Tradeoff: These guidelines bias toward caution over speed. For trivial tasks, use judgment.
1. Think Before Coding
Don't assume. Don't hide confusion. Surface tradeoffs.
Before implementing:
- State your assumptions explicitly. If uncertain, ask.
- If multiple interpretations exist, present them - don't pick silently.
- If a simpler approach exists, say so. Push back when warranted.
- If something is unclear, stop. Name what's confusing. Ask.
2. Simplicity First
Minimum code that solves the problem. Nothing speculative.
- No features beyond what was asked.
- No abstractions for single-use code.
- No "flexibility" or "configurability" that wasn't requested.
- No error handling for impossible scenarios.
- No documentation files (MD, reports, etc.) unless explicitly requested.
- If you write 200 lines and it could be 50, rewrite it.
Ask yourself: "Would a senior engineer say this is overcomplicated?" If yes, simplify.
3. Surgical Changes
Touch only what you must. Clean up only your own mess.
When editing existing code:
- Don't go on unrelated cleanup sprees, but fix obvious issues (bugs, stale comments) adjacent to your changes.
- Don't refactor things that aren't broken.
- Use modern language idioms — follow project skills over legacy patterns in the file.
- Match existing code style (naming, formatting) unless it conflicts with best practices.
When your changes create orphans:
- Remove imports/variables/functions that your changes made unused.
The test: Every changed line should trace directly to the user's request, or to using a modern idiom the project's skills require.
4. Goal-Driven Execution
Define success criteria. Loop until verified.
Transform tasks into verifiable goals:
- "Add validation" → "Implement checks, verify existing tests still pass"
- "Fix the bug" → "Write a test that reproduces it, then make it pass"
- "Refactor X" → "Ensure tests pass before and after"
For multi-step tasks, state a brief plan:
1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]
Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.
Applying the Guidelines
When working on a task:
- Before starting: State assumptions and ask clarifying questions
- While coding: Keep it minimal - resist over-engineering
- During changes: Make surgical edits, use modern idioms in new/changed code
- Throughout: Define success criteria and verify against them
These guidelines help prevent common pitfalls:
- Over-complicating simple tasks
- Making assumptions instead of asking
- Introducing unnecessary changes
- Losing sight of the original goal