karpathy-check

karpathy-check is a command for Claude Code from athola/claude-night-market. It costs 28 tokens per session (578 once invoked), scanned A, original, MIT.

A pre-flight command that checks a proposed coding task against four principles: think first, keep it simple, make focused edits, and verify the goal.

In plain words
What is it for?
Use it before implementation to receive a PASS, NEEDS CLARIFICATION, or REWORK verdict for a task.
Why use it?
It helps reveal hidden assumptions, overcomplicated plans, unrelated changes, and missing proof that the work is complete.

Command for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the imbue plugin — 5 commands, 1 agent shipped together

Good fit Use it before implementation to receive a PASS, NEEDS CLARIFICATION, or REWORK verdict for a task.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/athola/claude-night-market/karpathy-check
Install

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.

Clone the repo
git clone --depth 1 https://github.com/athola/claude-night-market

Made for: Claude Code.

Or install imbue, the plugin that ships this one along with the rest of its 5 commands, 1 agent.

Wrote 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.

agentmods badge for karpathy-check

README.md
[![agentmods](https://agentmods.dev/badge/commands/athola/claude-night-market/karpathy-check/github.svg)](https://agentmods.dev/commands/athola/claude-night-market/karpathy-check)
Your own site
<a href="https://agentmods.dev/commands/athola/claude-night-market/karpathy-check"><img src="https://agentmods.dev/badge/commands/athola/claude-night-market/karpathy-check/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for karpathy-check

Your own site · 80×15
<a href="https://agentmods.dev/commands/athola/claude-night-market/karpathy-check"><img src="https://agentmods.dev/badge/commands/athola/claude-night-market/karpathy-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 28 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 578 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00028 $0.00578
Opus 5 $0.00014 $0.00289
Sonnet 5 $0.00006 $0.00116
Haiku 4.5 $0.00003 $0.00058

Measured 8d ago against content hash acba201b12a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

karpathy-check 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 8d 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.

plugins/imbue/commands/karpathy-check.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Karpathy Check

A four-question pre-flight gate adapted from observations on common LLM coding pitfalls. Loads the imbue:karpathy-principles skill and walks each principle as a checkable question.

Usage

# Run as an inline pre-flight before starting work
/imbue:karpathy-check

# Pass a task description to anchor the check
/imbue:karpathy-check Add rate limiting to the signup endpoint

What It Does

  1. Loads Skill(imbue:karpathy-principles).
  2. Walks the four-question battery:
    • Think Before Coding: did I list assumptions, or guess silently?
    • Simplicity First: would a senior engineer call this overcomplicated?
    • Surgical Changes: does every changed line trace to the request?
    • Goal-Driven Execution: can I prove this is done with a check, not a feeling?
  3. For each question, captures the answer and any blockers.
  4. Outputs a verdict: PASS, NEEDS CLARIFICATION, or REWORK.

Verdict Semantics

  • PASS: all four answered concretely. Begin implementation.
  • NEEDS CLARIFICATION: at least one assumption or ambiguity needs the user's input. Surface the question, do not guess.
  • REWORK: the plan as drafted will violate one or more principles. Reshape before starting.

When to Use

  • Before any non-trivial implementation
  • When converting a vague request into a verifiable plan
  • During code review, applied to your own diff
  • When a task feels "too easy" (often a sign of hidden assumptions)

When NOT to Use

  • Trivial typos and one-line fixes
  • Throwaway scripts and exploratory spikes
  • Documentation-only changes
  • Production fires where the failing test wait is too long

See modules/tradeoff-acknowledgment.md in the skill for the full boundary discussion.

  • Skill(imbue:karpathy-principles) - the underlying four-principle synthesis
  • Skill(imbue:scope-guard) - worthiness scoring before the four-question gate
  • Skill(imbue:proof-of-work) - Iron Law TDD enforcement after the gate clears
  • /imbue:justify - post-implementation audit using the same principles in reverse

Read the full file on GitHub · 80 lines

Changes

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.

  1. 8d ago First seen · 80 lines · 28 tokens per session scan A acba201b12a2

Subscribe to this mod's changes

karpathy-check is a command published in the GitHub repository athola/claude-night-market (337 stars, last pushed yesterday), licensed MIT. It adds 28 tokens to every session and 578 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 2026-09-03.