cordon

cordon is a plugin for Gemini CLI from ilyautov/cordon. Its token cost is not measured, scanned A, original, MIT.

A boundary layer for handling untrusted content before it reaches an agent's actions. It records where information came from and keeps tool calls within the stated intent.

In plain words
What is it for?
Use it when an agent reads external or untrusted content and may then call tools or take actions. It is intended for controlling information flow and action boundaries.
Why use it?
Agents may receive instructions or data from sources that should not control their actions. This reduces the risk of hidden instructions changing what the agent does.

Plugin for Gemini CLI

Written for Gemini CLI: a Gemini CLI extension manifest.

Good fit Use it when an agent reads external or untrusted content and may then call tools or take actions. It is intended for controlling information flow and action boundaries.

Compare 6 plugins from other repositories ↓
Install with agentmods
npx agentmods add plugins/ilyautov/cordon/gemini-extension
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/ilyautov/cordon

Made for: Gemini CLI.

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 cordon

README.md
[![agentmods](https://agentmods.dev/badge/plugins/ilyautov/cordon/gemini-extension/github.svg)](https://agentmods.dev/plugins/ilyautov/cordon/gemini-extension)
Your own site
<a href="https://agentmods.dev/plugins/ilyautov/cordon/gemini-extension"><img src="https://agentmods.dev/badge/plugins/ilyautov/cordon/gemini-extension/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 cordon

Your own site · 80×15
<a href="https://agentmods.dev/plugins/ilyautov/cordon/gemini-extension"><img src="https://agentmods.dev/badge/plugins/ilyautov/cordon/gemini-extension.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 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 original No closer match found in the catalogue.
Security

Grade A, and why

cordon 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.

gemini-extension.json · 6 lines

What it actually says

{
  "name": "cordon",
  "version": "0.5.0",
  "description": "A deterministic layer between untrusted content and agent actions: it removes the hidden layer, remembers where data came from, and keeps calls inside the boundaries of the intent."
}
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 · 6 lines scan A 5c7ef20c85a7

Subscribe to this mod's changes

cordon is a plugin published in the GitHub repository ilyautov/cordon (2 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 2026-09-11.