What is the key difference between Checker MCP and Kastell?

Checker MCP belongs to the Security category with local stdio execution, while Kastell belongs to the Security category with local stdio execution.

How do I install Checker MCP or Kastell in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are Checker MCP and Kastell free or paid?

Checker MCP operates under a Free / Open Source model (No auth required). Kastell operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Checker MCP lists 3 tools with 2 views and 0 GitHub stars. Kastell lists 6 tools with 4 views and 59 GitHub stars.

Can I use both Checker MCP and Kastell together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

Side-by-Side Model Context Protocol Comparison

Checker MCP vs Kastell

In-depth architectural comparison of the Checker MCP and Kastell MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

At a Glance & Executive Verdict

Checker MCP

Security · Local stdio

Quality: 56/100 (Good) | Auth: No auth required

Kastell

Security · Local stdio

Quality: 63/100 (Good) | Auth: No auth required

Verdict Summary: Choose Checker MCP if you need specialized Security tools running via a local process. Choose Kastell if your workspace requires Security integration with local subprocess execution. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose Checker MCP when:

You need dedicated capabilities in the Security domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
Primary tools included: check_domain, list_checks, explain_check.

Explore Checker MCP Details

Choose Kastell when:

You need dedicated capabilities in the Security domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
Primary tools included: Server security audits with remediation, SSH hardening and fail2ban setup, UFW firewall management.

Explore Kastell Details

Feature & Specification Comparison

Specification	Checker MCP OksigeniaSL Security	Kastell kastelldev Security
Summary	Domain security & privacy checker: 17 live checks (SPF, DMARC, DKIM, DNSSEC, TLS, CAA, security headers) scored 0-100 with remediation. Local-first, zero telemetry. In the official MCP Registry as com.oksigenia/checker-mcp; npm @oksigenia/checker-mcp.	Server security auditing and hardening toolkit. 413 security checks across 29 categories (SSH, Firewall, Docker, TLS, HTTP Headers), CIS/PCI-DSS/HIPAA compliance mapping, 19-step production hardening, fleet management, and forensic evidence collection. Supports Hetzner, DigitalOcean, Vultr, and Linode. 13 MCP tools.
Category & Scope

Tools & Capabilities Breakdown

Checker MCP Tools (3)

check_domain

Scan a domain or URL and return a scored report from real live checks.

list_checks

List every check grouped by category, with the reason each one matters.

explain_check

Explain a single check by id, why it matters, and how to remediate a failure.

Kastell Tools (6)

Server security audits with remediation

SSH hardening and fail2ban setup

UFW firewall management

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

Checker MCP Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "oksigeniasl-checker-mcp": {
      "command": "npx",
      "args": [
        "-y",
        "@oksigenia/checker-mcp"
      ]
    }
  }
}

Kastell Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "kastelldev-kastell": {
      "command": "npx",
      "args": [
        "-y",
        "kastell"
      ]
    }
  }
}

Frequently Asked Questions

Checker MCP is categorized under Security and uses a local stdio subprocess. In contrast, Kastell belongs to Security using local stdio subprocess. Select Checker MCP when you need capabilities focused on security and Kastell when you require tools for security.

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