Kastell
Run 413-point server security audits and hardening guidance across Hetzner, DigitalOcean, Vultr, and Linode fleets from your agent.
Overview
Kastell is a MCP server for the Ship phase that runs 413 server security checks and fleet hardening across four cloud providers.
What is this MCP server?
- 413 automated server security checks in the published server description
- Fleet management and hardening across 4 cloud providers: Hetzner, DigitalOcean, Vultr, Linode
- Optional per-provider API tokens via HETZNER_TOKEN, DIGITALOCEAN_TOKEN, VULTR_TOKEN, LINODE_TOKEN
- npm stdio package identifier kastell (v1.14.0) for MCP hosts
- Agent-driven audits for indie builders running multi-VPS infrastructure without a dedicated SecOps hire
- 413 server security checks per server description
- MCP package version 1.14.0 (npm identifier kastell)
Community signal: 52 GitHub stars.
What problem does it solve?
Spinning up cheap VPS fleets is easy for solopreneurs, but nobody has time to manually verify hundreds of security settings on every box.
Who is it for?
Indie SaaS founders managing multiple Linux servers on Hetzner, DO, Vultr, or Linode who want agent-assisted baseline audits before go-live.
Skip if: Builders on serverless-only platforms with no VM API tokens, or teams needing formal compliance attestations without human review.
What do I get? / Deliverables
After registering Kastell with provider tokens, your agent can audit and guide hardening across your cloud servers from one MCP surface.
- Agent-invokable security audit results across configured cloud accounts
- Hardening-oriented follow-ups aligned to the 413-check catalog claim
- Repeatable fleet audit workflow before ship and after infra changes
Recommended MCP Servers
Journey fit
How it compares
Cloud VM security audit MCP, not an application SAST skill or generic infrastructure provisioner.
Common Questions / FAQ
Who is Kastell for?
Solo builders and tiny teams operating Linux fleets on supported clouds who want MCP-driven security audits and hardening hints.
When should I use Kastell?
Use it in ship/security before launch, after provisioning new servers, or when hardening SSH, firewall, and exposure settings across a fleet.
How do I add Kastell to my agent?
Install the npm kastell MCP package (stdio), set optional HETZNER_TOKEN, DIGITALOCEAN_TOKEN, VULTR_TOKEN, and/or LINODE_TOKEN env vars, then add the server in your MCP client config.