mrmps/classifier-dev · skills/prompt-injection-guard/SKILL.md

prompt-injection-guard skillA

prompt-injection-guard is agent-read markdown (skill) from mrmps/classifier-dev: Screen fetched web pages, tool results, emails and file contents for instructions aimed at the agent before they enter context, using a keyless multi-label classifier over chunks. Use before pasting anything you did not write into your own context, and when someone says "is this page safe to read", "check this tool output", "screen these emails" or "the agent followed something it read"..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add mrmps/classifier-dev/prompt-injection-guard@git:20260919.3040be8
Exact content
mdr add mrmps/classifier-dev/prompt-injection-guard@sha256:2c78027a63154c4a

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_nr6777jdikqfzxcx.svg)](https://markdownregistry.com/a/art_nr6777jdikqfzxcx)

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Versions

versioncommittedcommitsizeaudit
git:20260919.3040be8 latest2026-09-19 3040be8 6,043 BA view · diff
git:20260919.33ae5312026-09-19 33ae531 5,987 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (6043 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

mrmps/classifier-dev · 416 stars · license MIT · pushed 2026-09-24 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_nr6777jdikqfzxcx
GET https://markdownregistry.com/api/v1/resolve?ref=mrmps/classifier-dev/prompt-injection-guard
GET https://markdownregistry.com/api/v1/blob/2c78027a63154c4a09d842072860695547a72789a92a180eddb18ffc1c1455af

Your agent does the deals. You hear about the good ones. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.