prompt-rejector

prompt-rejector is a plugin for Claude Code from revsmoke/promptrejectormcp. Its manifest loads nothing; the 1 skill, 1 MCP server it bundles cost 75 tokens per session together, scanned A, original, ISC.

A plugin that screens prompts, skill files, and MCP tool descriptions for security risks using configurable reasoning models.

In plain words
What is it for?
Use it to review prompts, agent skills, and MCP tools for prompt-injection and related security concerns.
Why use it?
It helps detect unsafe or manipulative instructions before they influence an AI agent.

Plugin for Claude Code

Written for Claude Code: a Claude Code plugin manifest.

Good fit Use it to review prompts, agent skills, and MCP tools for prompt-injection and related security concerns.

Compare 6 plugins from other repositories ↓
Install in Claude Code
/plugin marketplace add revsmoke/promptrejectormcp
/plugin install prompt-rejector
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/revsmoke/promptrejectormcp

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 prompt-rejector

README.md
[![agentmods](https://agentmods.dev/badge/plugins/revsmoke/promptrejectormcp/prompt-rejector/github.svg)](https://agentmods.dev/plugins/revsmoke/promptrejectormcp/prompt-rejector)
Your own site
<a href="https://agentmods.dev/plugins/revsmoke/promptrejectormcp/prompt-rejector"><img src="https://agentmods.dev/badge/plugins/revsmoke/promptrejectormcp/prompt-rejector/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 prompt-rejector

Your own site · 80×15
<a href="https://agentmods.dev/plugins/revsmoke/promptrejectormcp/prompt-rejector"><img src="https://agentmods.dev/badge/plugins/revsmoke/promptrejectormcp/prompt-rejector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured The manifest loads nothing itself; its 1 skill, 1 MCP server cost 75 tokens a session between them.
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.
Security

Grade A, and why

prompt-rejector 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 yesterday.

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/prompt-rejector/.claude-plugin/plugin.json · 18 lines

What it actually says

{
  "name": "prompt-rejector",
  "version": "1.2.0",
  "description": "Screen prompts, skills and MCP tools with TypeSafe judgments and configurable reasoning models.",
  "author": {
    "name": "Bryan Rice"
  },
  "homepage": "https://github.com/revsmoke/promptrejectormcp",
  "repository": "https://github.com/revsmoke/promptrejectormcp",
  "license": "ISC",
  "keywords": [
    "security",
    "mcp",
    "prompt-injection",
    "typesafe"
  ]
}
Contents

What it installs

The manifest is a name and a version. 1 skill, 1 MCP server travel with it, and installing the plugin installs all of them — 75 tokens a session between them. Each is measured on its own page, and each can be installed alone.

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. yesterday First seen · 18 lines scan A 4393f00df03b

Subscribe to this mod's changes

prompt-rejector is a plugin published in the GitHub repository revsmoke/promptrejectormcp (2 stars, last pushed today), licensed ISC. 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 2026-09-21.

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