vpn-access-control

vpn-access-control is a skill for Claude Code, Codex from LuuOW/meridian-mcp. It costs 54 tokens per session (2,482 once invoked), scanned A, original, MIT.

A set of rules for limiting access to services on a VPS, or virtual private server, so that selected ports and domains are reachable only through a VPN. It coordinates the server firewall, Docker's network rules, and nginx.

In plain words
What is it for?
Use it to protect host services and Docker containers, restrict individual domains, and provide on/off access aliases for VPN-gated deployments.
Why use it?
It closes access paths that a firewall alone may miss, especially ports exposed by Docker, while keeping public parts of a site available.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it to protect host services and Docker containers, restrict individual domains, and provide on/off access aliases for VPN-gated deployments.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/luuow/meridian-mcp/vpn-access-control
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add LuuOW/meridian-mcp --skill vpn-access-control
Clone the repo
git clone --depth 1 https://github.com/LuuOW/meridian-mcp

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for vpn-access-control

README.md
[![agentmods](https://agentmods.dev/badge/skills/luuow/meridian-mcp/vpn-access-control/github.svg)](https://agentmods.dev/skills/luuow/meridian-mcp/vpn-access-control)
Your own site
<a href="https://agentmods.dev/skills/luuow/meridian-mcp/vpn-access-control"><img src="https://agentmods.dev/badge/skills/luuow/meridian-mcp/vpn-access-control/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for vpn-access-control

Your own site · 80×15
<a href="https://agentmods.dev/skills/luuow/meridian-mcp/vpn-access-control"><img src="https://agentmods.dev/badge/skills/luuow/meridian-mcp/vpn-access-control.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,482 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00054 $0.02482
Opus 5 $0.00027 $0.01241
Sonnet 5 $0.00011 $0.00496
Haiku 4.5 $0.00005 $0.00248

Measured 7d ago against content hash 85521307fe46, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

vpn-access-control scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -m 3 http://45.9.190.170:6333 # should time out / connection refused
skills/vpn-access-control/SKILL.md · 233 lines

How it starts

The opening of the file, as written. The whole thing — 233 lines — stays where its author put it; the contents beside it link to each section on GitHub.

vpn-access-control

Access control pattern for VPS deployments where internal services must be reachable only from a WireGuard tunnel while the public site stays open. Three layers must be coordinated: UFW (for PM2/host processes), DOCKER-USER iptables chain (for Docker-exposed ports), and nginx snippets (for domain-level restrictions).

Why UFW Alone Is Not Enough

Docker bypasses UFW by writing directly to iptables nat PREROUTING rules. A port bound 0.0.0.0:6333 in a Docker compose file is reachable from the internet even if UFW has no rule for 6333. You must also lock the DOCKER-USER chain.

UFW rules     → protect host-process ports (PM2, systemd services)
DOCKER-USER   → protect Docker-exposed ports (all docker compose `ports:`)
nginx snippet → protect domains at the HTTP layer (optional, defence-in-depth)

DOCKER-USER Lock

# Block all external non-VPN traffic reaching Docker containers
iptables -I DOCKER-USER -i eth0 '!' -s 10.0.0.0/24 -j DROP

# Verify
iptables -L DOCKER-USER -n --line-numbers
# Expected:
# 1  DROP  0  --  !10.0.0.0/24  0.0.0.0/0
# 2  ACCEPT 0  --  172.16.0.0/12  0.0.0.0/0   (Docker internal — must be present)
# 3  ACCEPT 0  --  0.0.0.0/0    0.0.0.0/0    ctstate RELATED,ESTABLISHED

# Remove the lock
iptables -D DOCKER-USER -i eth0 '!' -s 10.0.0.0/24 -j DROP

Note: The -i eth0 flag scopes the rule to the external interface. Without it, you also block Docker-internal traffic. Use ip link to verify your interface name (eth0, ens3, enp3s0 — it varies by VPS provider).

UFW — VPN-Only Port Rules

# Enable UFW safely — allow SSH first or you lock yourself out
ufw allow 22/tcp     comment "SSH"
ufw allow 443        comment "WireGuard"
ufw allow 80/tcp     comment "HTTP"
ufw allow 8082/tcp   comment "nginx public site"
ufw --force enable

# Restrict a port to VPN subnet only
ufw allow from 10.0.0.0/24 to any port 4401 proto tcp comment "VPN-only :4401"

# Restore a port to public
ufw delete allow from 10.0.0.0/24 to any port 4401 proto tcp
ufw allow 4401/tcp

# Check result
ufw status verbose

Read the full file on GitHub · 233 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 233 lines · 54 tokens per session scan A 85521307fe46

Subscribe to this mod's changes

vpn-access-control is a skill published in the GitHub repository LuuOW/meridian-mcp (0 stars, last pushed yesterday), licensed MIT. It adds 54 tokens to every session and 2,482 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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