MCP Firewall vs Shield

In-depth architectural comparison of the MCP Firewall and Shield 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.

Which MCP Server Should You Choose?

Choose MCP Firewall 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: YAML-based inbound and outbound policies, Secret scanning with regex and entropy checks, Response redaction and prompt-injection blocking.

Explore MCP Firewall Details

Choose Shield 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: Pre-execution MCP call guardrails, TOFU tool-catalog pinning, Tool description and result scanning.

Explore Shield Details

Feature & Specification Comparison

Specification	MCP Firewall behrensd Security	Shield AperionAI Security
Summary	Deterministic security proxy (iptables for MCP) that intercepts tool calls, enforces YAML policies, scans for secret leakage, and logs everything. No AI, no cloud.	Local guardrail proxy for AI coding agents. Wraps any MCP server (stdio or Streamable HTTP) and blocks destructive tool calls — DROP TABLE, rm -rf, force-push — before they execute. MCP supply-chain protection: TOFU tool-catalog pinning against rug pulls, plus tool-description and tool-result scanning for tool poisoning and prompt injection. 51 starter rules, approval gates, audit logging. Single binary, Apache-2.0.
Category & Scope

Tools & Capabilities Breakdown

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).

{
  "mcpServers": {
    "behrensd-mcp-firewall": {
      "command": "npx",
      "args": [
        "-y",
        "mcpwall"
      ]
    }
  }
}

{
  "mcpServers": {
    "aperionai-shield": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-postgres"
      ]
    }
  }
}

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