cache-tax

cache-tax is a plugin for Claude Code from karanb192/claude-code-hooks. Its token cost is not measured, scanned A, original, MIT.

The comeback price of a cold prompt cache, shown before you pay it. A UserPromptSubmit guard warns (or refuses once) when your next message will re-write a lapsed 1-hour cache at up to 80x the read rate, a SessionStart hook prices a stale resume, and the same script is a one-line status line segment with the minutes…

Plugin for Claude Code

Written for Claude Code: UserPromptSubmit hook event.

Install in Claude Code
/plugin marketplace add karanb192/claude-code-hooks/plugin install cache-tax
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/karanb192/claude-code-hooks

Made for: Claude Code.

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 cache-tax

README.md
[![agentmods](https://agentmods.dev/badge/plugins/karanb192/claude-code-hooks/cache-tax.svg)](https://agentmods.dev/plugins/karanb192/claude-code-hooks/cache-tax)
Your own site
<a href="https://agentmods.dev/plugins/karanb192/claude-code-hooks/cache-tax"><img src="https://agentmods.dev/badge/plugins/karanb192/claude-code-hooks/cache-tax.svg" alt="Measured on agentmods" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Security

Grade A, and why

cache-tax 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 today.

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/cache-tax/.claude-plugin/plugin.json · 23 lines

What it actually says

{
  "name": "cache-tax",
  "description": "The comeback price of a cold prompt cache, shown before you pay it. A UserPromptSubmit guard warns (or refuses once) when your next message will re-write a lapsed 1-hour cache at up to 80x the read rate, a SessionStart hook prices a stale resume, and the same script is a one-line status line segment with the minutes left and the cold-comeback cost.",
  "version": "1.0.1",
  "author": {
    "name": "Karan Bansal",
    "url": "https://github.com/karanb192"
  },
  "homepage": "https://github.com/karanb192/claude-code-hooks",
  "license": "MIT",
  "keywords": [
    "claude-code",
    "hooks",
    "cost",
    "prompt-cache",
    "cache",
    "observability",
    "statusline",
    "userpromptsubmit",
    "sessionstart"
  ]
}
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. today First seen · 23 lines scan A ee10cc056abe

Subscribe to this mod's changes

cache-tax is a plugin published in the GitHub repository karanb192/claude-code-hooks (503 stars, last pushed yesterday), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-09-07.