What is kastell-plugin?

A plugin for managing and securing cloud servers, including provisioning, security audits, hardening, backups, and fleet management.

Use it to manage servers on Hetzner, DigitalOcean, Vultr, and Linode, audit their security, apply hardening, create backups, and manage multiple servers.

It helps operators handle server setup and security work across several cloud providers from one set of tools.

kastell-plugin — Plugin by kastelldev

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.

Claude Code

/plugin marketplace add kastelldev/kastell

agentmods

npx agentmods add plugins/kastelldev/kastell/kastell-plugin

Clone the repo

git clone --depth 1 https://github.com/kastelldev/kastell

Made for: Claude Code.

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

kastell-plugin 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.

kastell-plugin/.claude-plugin/plugin.json · 21 lines

What it actually says

{
  "name": "kastell",
  "version": "2.3.0",
  "description": "Autonomous server security and infrastructure management. First-party MCP tools for cloud server provisioning, security auditing, hardening, backup, and fleet management across Hetzner, DigitalOcean, Vultr, and Linode.",
  "author": {
    "name": "kastelldev"
  },
  "homepage": "https://kastell.dev",
  "repository": "https://github.com/kastelldev/kastell",
  "keywords": [
    "server",
    "security",
    "infrastructure",
    "mcp",
    "audit",
    "hardening",
    "vps",
    "cloud"
  ]
}

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.

yesterday First seen · 21 lines scan A 124f7b80a358

Subscribe to this mod's changes

kastell-plugin is a plugin published in the GitHub repository kastelldev/kastell (59 stars, last pushed 16d ago), licensed Apache-2.0. 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 2026-08-30.

DevOps and cloud Productivity Security automation cli coolify docker hetzner vps

kastell-plugin

Getting it into your agent

Grade A, and why

Nothing flagged

What it actually says

What this file has done since we first saw it

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