What is the key difference between Emilia Protocol and Kastell?

Emilia Protocol belongs to the Security category with local stdio execution, while Kastell belongs to the Security category with local stdio execution.

How do I install Emilia Protocol 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 Emilia Protocol and Kastell free or paid?

Emilia Protocol 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?

Emilia Protocol lists 3 tools with 4 views and 617 GitHub stars. Kastell lists 6 tools with 4 views and 59 GitHub stars.

Can I use both Emilia Protocol 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

Emilia Protocol vs Kastell

In-depth architectural comparison of the Emilia Protocol 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

Emilia Protocol

Security · Local stdio

Quality: 71/100 (Great) | Auth: No auth required

Kastell

Security · Local stdio

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

Verdict Summary: Choose Emilia Protocol 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 Emilia Protocol 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: ep_guard_action, ep_check_signoff, ep_verify_receipt.

Explore Emilia Protocol 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	Emilia Protocol emiliaprotocol Security	Kastell kastelldev Security
Summary	Human sign-off + trust receipts for AI agents: requires a named human's approval before an irreversible action (payment release, record change, deploy), then mints an offline-verifiable Ed25519 Trust Receipt. Also exposes trust profiles, receipt verification, disputes, and delegation. Apache-2.0; policy engine formally verified. Install: npx -y @emilia-protocol/mcp-server.	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.

Tools & Capabilities Breakdown

Emilia Protocol Tools (3)

ep_guard_action

Request authorization before an irreversible action: payments, wire transfers, fund releases, deletions, record or account changes, or sending messages with real-world effect. Submits the exact action for policy evaluation and human authorization. This MCP tool does not itself sit at the executor choke point: even after approval, the executor MUST match the returned action_hash and atomically consume the receipt before effect. If BLOCKED, poll ep_check_signoff with the receipt_id.

ep_check_signoff

Poll a pending authorization after ep_guard_action returns BLOCKED. Pass the receipt_id. Returns PENDING, APPROVED_PENDING_CONSUME, CONSUMED, or DENIED. Approval alone is not permission to execute: the executor must match action_hash and atomically consume the receipt at its own choke point.

ep_verify_receipt

Ask the configured EMILIA service to verify a stored trust receipt and report its hash and anchor status. Read-only, but not an offline verifier: the result is the service response for the supplied receipt_id.

Kastell Tools (6)

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).

Emilia Protocol Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "emiliaprotocol-emilia-protocol": {
      "command": "npx",
      "args": [
        "-y",
        "@emilia-protocol/mcp-server"
      ]
    }
  }
}

Kastell Configuration

mcpServers (Claude Desktop / Cursor)

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

Frequently Asked Questions

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

More alternatives to Emilia Protocol More alternatives to Kastell Security category hub