leakage-check

leakage-check is a command for Claude Code from yeaight7/agent-powerups. It costs 10 tokens per session (220 once invoked), scanned A, original, Apache-2.0.

A command that checks machine-learning preprocessing and data-splitting code for target leakage. Target leakage means that information about the answer accidentally enters the model's inputs.

In plain words
What is it for?
Use it to audit scalers, encoders, imputers, train-validation-test splits, and features that reveal the target.
Why use it?
It catches unsafe transformations and features that can make test results falsely high, such as fitting a scaler on all data before splitting it.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter.

Part of the machine-learning-ops plugin — 7 skills, 4 commands, 3 agents shipped together

Good fit Use it to audit scalers, encoders, imputers, train-validation-test splits, and features that reveal the target.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/yeaight7/agent-powerups/leakage-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/yeaight7/agent-powerups

Made for: Claude Code.

Or install machine-learning-ops, the plugin that ships this one along with the rest of its 7 skills, 4 commands, 3 agents.

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 leakage-check

README.md
[![agentmods](https://agentmods.dev/badge/commands/yeaight7/agent-powerups/leakage-check/github.svg)](https://agentmods.dev/commands/yeaight7/agent-powerups/leakage-check)
Your own site
<a href="https://agentmods.dev/commands/yeaight7/agent-powerups/leakage-check"><img src="https://agentmods.dev/badge/commands/yeaight7/agent-powerups/leakage-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 leakage-check

Your own site · 80×15
<a href="https://agentmods.dev/commands/yeaight7/agent-powerups/leakage-check"><img src="https://agentmods.dev/badge/commands/yeaight7/agent-powerups/leakage-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 220 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 $0.00010 $0.00220
Opus 5.5 $0.00004 $0.00088
Sonnet 5.5 $0.00002 $0.00044
Haiku 4.5 $0.00001 $0.00022

Measured 1mo ago against content hash 1bcf450eac10, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

leakage-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 1mo 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/machine-learning-ops/commands/leakage-check.md · 18 lines

What it actually says

Leakage Check Command

CRITICAL BEHAVIORAL RULES

  1. Hunt the Future: Target leakage occurs when information from the future (the target variable) sneaks into the training features.

Execution Steps

  1. Read the preprocessing and splitting code.
  2. Split First: Verify that the dataset is split into train/val/test before any global transformations are applied.
  3. Imputation Leakage: Verify that scalers, encoders, and imputers are fit ONLY on the training set, and transform is applied to train/val/test. If fit_transform is used on the entire dataset, flag it as a critical leakage error.
  4. Feature Leakage: Look for features that are direct proxies for the target (e.g., a "cancellation_date" feature when predicting churn).
  5. Output: Generate a Leakage Audit Report highlighting unsafe transformations and risky features.
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. 1mo ago First seen · 18 lines · 10 tokens per session scan A 1bcf450eac10

Subscribe to this mod's changes

leakage-check is a command published in the GitHub repository yeaight7/agent-powerups (6 stars, last pushed 19d ago), licensed Apache-2.0. It adds 10 tokens to every session and 220 once invoked, about $0.0000 per session on Opus 5.5. 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 2026-09-14.