MCP Servers

behrensd/mcp-firewall

Name: behrensd/mcp-firewall
Author: Various

Deterministic security proxy for MCP tool calls — iptables for MCP

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Our verdict

Not reviewed yet

We have not reviewed behrensd/mcp-firewall yet

No one at Enterprise DNA has checked this listing against its sources. The description comes from public listings gathered automatically. Any fact below shows where it came from and when it was last checked.

How we review records

From the listing

About behrensd/mcp-firewall

A deterministic security proxy for MCP tool calls that enforces rules before forwarding or blocking requests. Inspired by iptables, it provides explicit rule-based control over which MCP tools can be invoked and by whom. Written in TypeScript, it runs as a middleware layer between the MCP client and server.

Best for

Developers needing a simple, deterministic firewall for MCP-based applications

Use cases

Restrict MCP tool access to authorized clients only
Audit and log all MCP tool invocations in deterministic order
Enforce rate limiting or tool allowlists/denylists

Notes

3 stars on GitHub. Last updated 2026-02-25.

Pros

Deterministic behavior with explicit rule sets
Lightweight and focused on a single security function
Familiar iptables-style syntax for developers

Cons

Niche tool with low community adoption (3 stars)
Requires understanding of MCP and iptables-like rule syntax
May not cover all MCP protocol edge cases or advanced threat patterns

Key facts

What we have checked

Days since the last commit: 36; Checked 26 Oct 2026GitHub
GitHub forks: 1; Checked 26 Oct 2026GitHub
GitHub stars: 5; Checked 26 Oct 2026GitHub
Open issues: 2; Checked 26 Oct 2026GitHub
Releases in the last 90 days: 0; Checked 26 Oct 2026GitHub

Each value shows when we last confirmed it and where it came from. Values we have not confirmed are left out, never guessed.

How to use

How to set it up

As the listing publishes it. We have not run this install.

Install

npx mcpwall -- npx -y @modelcontextprotocol/server-filesystem /path/to/dir

Tools exposed

not_under
response_contains
response_contains_regex
response_size_exceeds
log_only

Clients the listing names (not checked here)

Claude Code, Cursor, Windsurf, VS Code

Install

Add behrensd/mcp-firewall to your client

Not verified yet

Our lab has not run this server yet. "Config checked" on a client means the recipe matches that client's documented config format; it does not mean we ran it.

Claude Code

Config checked

Run in your terminal (runs on your computer)

claude mcp add --transport stdio behrensd-mcp-firewall -- npx -y mcpwall@0.1.2

Version 0.1.2 · From the Official MCP registry, read 24 Oct 2026 · Format checked against Claude Code's config docs

Claude Desktop

Config checked

Add to claude_desktop_config.json (runs on your computer)

{
  "mcpServers": {
    "behrensd-mcp-firewall": {
      "command": "npx",
      "args": [
        "-y",
        "mcpwall@0.1.2"
      ]
    }
  }
}

Version 0.1.2 · From the Official MCP registry, read 24 Oct 2026 · Format checked against Claude Desktop's config docs

Cursor

Config checked

Add to .cursor/mcp.json (runs on your computer)

{
  "mcpServers": {
    "behrensd-mcp-firewall": {
      "command": "npx",
      "args": [
        "-y",
        "mcpwall@0.1.2"
      ]
    }
  }
}

Version 0.1.2 · From the Official MCP registry, read 24 Oct 2026 · Format checked against Cursor's config docs

VS Code

Config checked

Add to .vscode/mcp.json (runs on your computer)

{
  "servers": {
    "behrensd-mcp-firewall": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mcpwall@0.1.2"
      ]
    }
  }
}

Version 0.1.2 · From the Official MCP registry, read 24 Oct 2026 · Format checked against VS Code's config docs

Codex

Config checked

Add to ~/.codex/config.toml (runs on your computer)

[mcp_servers.behrensd-mcp-firewall]
command = "npx"
args = ["-y", "mcpwall@0.1.2"]

Version 0.1.2 · From the Official MCP registry, read 24 Oct 2026 · Format checked against Codex's config docs

ChatGPT: ChatGPT connects only to remote servers that need no API key.

Recipes come from the server's entry in the official MCP registry. Check the package name before you run it, and keep keys out of shared files.

Works with

What behrensd/mcp-firewall connects to

5 clients, each with how we know and when we checked.

Works with	Type	How we know	Checked
Claude Code	Client	Install recipe matches the client's documented formatRuns locally, version 0.1.2Config checked	24 Oct 2026Claude Code docs
Claude Desktop	Client	Install recipe matches the client's documented formatRuns locally, version 0.1.2Config checked	24 Oct 2026Claude Desktop docs
Cursor	Client	Install recipe matches the client's documented formatRuns locally, version 0.1.2Config checked	24 Oct 2026Cursor docs
VS Code	Client	Install recipe matches the client's documented formatRuns locally, version 0.1.2Config checked	24 Oct 2026VS Code docs
Codex	Client	Install recipe matches the client's documented formatRuns locally, version 0.1.2Config checked	24 Oct 2026Codex docs

Health and security

Is behrensd/mcp-firewall looked after, and what do its setup files show

Health score

37 out of 100

Does someone look after this repository? It does not say the code is good or safe. Worked out from GitHub signals checked 26 Oct 2026. How it is worked out

Part	Points	What we saw
Recent activity	29.5 of 30	Last push 36 days ago
Releases	0 of 15	0 releases in 90 days
Issue replies	Not counted	The latest check has no issue response reading (fewer than 3 measured issues, or issues switched off)
Maintainer	0 of 15	Owned by a single user
Official source	0 of 20	Community server

Sources

Where this comes from

GitHubRegistry
Checked 26 Oct 2026 · Days since the last commit, GitHub forks, GitHub stars, Open issues, Releases in the last 90 days

A source shows what was published when we checked it. It does not certify security, performance or a working installation. Read our method.

Changelog

What changed

No changes recorded yet. Releases, price changes and deprecations appear here, with their dates, once we track them for this record.

Pairs with

Other entries in the index that connect to this one. Click through to see the chain.

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