Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add rules/dasomel/oh-my-cursor/karpathy-guidelinesgit clone --depth 1 https://github.com/dasomel/oh-my-cursorWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/rules/dasomel/oh-my-cursor/karpathy-guidelines)<a href="https://agentmods.dev/rules/dasomel/oh-my-cursor/karpathy-guidelines"><img src="https://agentmods.dev/badge/rules/dasomel/oh-my-cursor/karpathy-guidelines.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00019 | $0.00484 |
| Opus 5 | $0.00010 | $0.00242 |
| Sonnet 5 | $0.00004 | $0.00097 |
| Haiku 4.5 | $0.00002 | $0.00048 |
Grade A, and why
karpathy-guidelines scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Karpathy Guidelines
Coding discipline inspired by Andrej Karpathy's principles.
Core Principles
1. Think Before Coding
- Understand the problem completely before writing any code
- If you can't explain the approach in plain language, you're not ready to code
- 10 minutes of thinking saves 2 hours of debugging
2. Simplicity Above All
- The best code is code you didn't write
- Every line of code is a liability — minimize it
- If a junior developer can't understand it, it's too complex
- Choose boring technology over clever solutions
3. Surgical Changes
- Change the minimum needed to solve the problem
- Don't "clean up" code around your change
- Don't refactor while fixing bugs
- One PR, one purpose
4. Verify Everything
- Don't trust your assumptions — run the code
- Write the test that would have caught this bug
- If you can't test it, you can't ship it
- "It works on my machine" is not verification
5. Read More Code Than You Write
- Read the existing code before changing it
- Understand why the code is the way it is
- The previous developer might have had a good reason
- Chesterton's Fence: don't remove something until you understand why it's there
Anti-Patterns to Avoid
- Resume-Driven Development — using fancy tech to learn it, not because it's needed
- Premature Abstraction — "we might need this later" (you won't)
- Config-Driven Everything — hardcode first, extract config only when needed
- Framework Tourism — switching frameworks instead of solving the actual problem
Decision Framework
Before writing code, ask:
- Can I solve this without code? (config change, removal, documentation)
- Can I solve this with less code? (simpler algorithm, existing library)
- Will someone else understand this in 6 months?
- Am I solving the actual problem or a hypothetical one?
Rules
- Delete code whenever possible — less is more
- Prefer explicit over implicit
- Prefer flat over nested
- Prefer simple over clever
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 62 lines · 19 tokens per session scan A ad0b039d4414
karpathy-guidelines is a cursor rule published in the GitHub repository dasomel/oh-my-cursor (2 stars, last pushed 6mo ago), licensed MIT. It adds 19 tokens to every session and 484 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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