stdio-shellguard

stdio-shellguard is an MCP server for Claude Code, Codex, Cursor from studiomeyer-io/mcp-stdio-shellguard. Its token cost is not measured, scanned A, original, MIT.

A local security layer for MCP servers that communicate over standard input and output. MCP is a way for an AI agent to use external tools; this add-on checks shell commands and blocks some remote-code-execution risks.

In plain words
What is it for?
Use it to guard local MCP stdio servers, audit command syntax with its AST tool, and block detected RCE attempts.
Why use it?
It adds checks against shell injection and unsafe code before an MCP server can carry out commands.

MCP server for Claude CodeCodexCursor

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.

agentmods
npx agentmods add mcp/studiomeyer-io/mcp-stdio-shellguard/stdio-shellguard
Clone the repo
git clone --depth 1 https://github.com/studiomeyer-io/mcp-stdio-shellguard

Made for: Claude Code, Codex, Cursor.

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 stdio-shellguard

README.md
[![agentmods](https://agentmods.dev/badge/mcp/studiomeyer-io/mcp-stdio-shellguard/stdio-shellguard.svg)](https://agentmods.dev/mcp/studiomeyer-io/mcp-stdio-shellguard/stdio-shellguard)
Your own site
<a href="https://agentmods.dev/mcp/studiomeyer-io/mcp-stdio-shellguard/stdio-shellguard"><img src="https://agentmods.dev/badge/mcp/studiomeyer-io/mcp-stdio-shellguard/stdio-shellguard.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. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

stdio-shellguard 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 3d 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.

server.json · 10 lines

What it actually says

{
  "stdio-shellguard": {
    "command": "npx",
    "args": [
      "-y",
      "mcp-stdio-shellguard"
    ],
    "env": {}
  }
}
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. 3d ago First seen · 10 lines scan A 8bc0a9dd7ffd

Subscribe to this mod's changes

stdio-shellguard is an MCP server published in the GitHub repository studiomeyer-io/mcp-stdio-shellguard (0 stars, last pushed 12d ago), licensed MIT. Its token cost is not measured: an MCP server costs its tool schemas, not its config file. 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 2026-08-31.