A home-network monitoring tool that finds devices, scans their open ports, tracks changes over time, measures internet traffic, and shows which websites each device contacts.

Use it to inventory devices, investigate exposed ports, compare the network with an earlier state, check total internet usage, and inspect DNS requests from individual devices.

It replaces several separate checks with one view of what is connected to your home network and what those devices are doing. A saved baseline makes new or missing devices easier to spot.

netmon — Skill for Claude Code by larsboes/Axon

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 larsboes/Axon --skill netmon

Clone the repo

git clone --depth 1 https://github.com/larsboes/Axon

Made for: Claude Code.

Or install home-automation, the plugin that ships this one along with the rest of its 10 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/larsboes/axon/netmon/github.svg)](https://agentmods.dev/skills/larsboes/axon/netmon)

Your own site

<a href="https://agentmods.dev/skills/larsboes/axon/netmon"><img src="https://agentmods.dev/badge/skills/larsboes/axon/netmon/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/larsboes/axon/netmon"><img src="https://agentmods.dev/badge/skills/larsboes/axon/netmon.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 174 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,541 The whole file, excluding the scripts and references it only reads on demand.

Security scan B 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.

Model	Per session	Once invoked
Fable 5.1	$0.00174	$0.01541
Opus 5.5	$0.00070	$0.00616
Sonnet 5.5	$0.00035	$0.00308
Haiku 4.5	$0.00017	$0.00154

Measured 2mo ago against content hash 116858019add, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

netmon scanned grade B 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 2mo 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

Pi.** Install it first (`sudo apt install nmap`, or `brew install nmap` on macOS) — the tool

Packs/home-automation/skills/netmon/SKILL.md · 100 lines

How it starts

The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.

netmon

Network visibility from wherever you run it — especially after isolating IoT onto its own VLAN. scan/ports/baseline/diff need only nmap + the Python stdlib and no credentials. traffic reads the Fritz!Box over TR-064 (credentials from Bitwarden at runtime). dns/egress read a resolver's query log over SSH. Nothing is pinned to one house.

Configuration

Non-secret config lives in the committed axon-overlay overlay (config/home-assistant.vars, resolved via $AXON_HOME_ROOT, falling back to the active deployment overlay). The one secret comes from Bitwarden at runtime.

What	Source	Default
Subnet to scan	`--subnet` / `$NETMON_SUBNET` / `NETMON_SUBNET` in `home-assistant.vars`	auto-derived from the primary interface as a `/24`
SSH target (dns/egress)	`$NETMON_SSH` / `NETMON_SSH` in `home-assistant.vars`	none — required for `dns`/`egress`
Resolver container	`$NETMON_DNS_CONTAINER`	`dnsmasq`
Fritz!Box host + user (traffic)	`FRITZBOX_HOST` / `FRITZBOX_USERNAME` in `home-assistant.vars`	none — required for `traffic`
Fritz!Box password (traffic)	Bitwarden item `$NETMON_BW_ITEM`, secret field `FRITZBOX_PASSWORD`	`home-assistant/netmon`

For subnet and SSH the env var wins if set, else the overlay config, else (subnet only) auto-derivation; the --subnet flag overrides everything. The bw item holds only the secret FRITZBOX_PASSWORD — the non-secret FRITZBOX_HOST/FRITZBOX_USERNAME live in home-assistant.vars (same split and shape as the fritz skill). Provision the password via Axon setup-secret.sh.

Run

# Inventory + drift (no credentials)
scripts/netmon scan                       # live hosts + MAC + vendor
scripts/netmon ports 10.0.0.45            # open ports on one host (default --top-ports 100)
scripts/netmon baseline                    # save the known-good snapshot
scripts/netmon diff                        # new / missing hosts since baseline

# WAN throughput (needs bw + fritzconnection)
export BW_SESSION=$(bw unlock --raw)
scripts/netmon traffic

# DNS egress (needs $NETMON_SSH)
export NETMON_SSH=user@resolver-host
scripts/netmon dns                         # top domains, all clients
scripts/netmon egress 10.0.0.128           # one device's external domains

Read the full file on GitHub · 100 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

2mo ago First seen · 100 lines · 174 tokens per session scan B 116858019add

Subscribe to this mod's changes

netmon is a skill published in the GitHub repository larsboes/Axon (1 stars, last pushed 1mo ago), licensed MIT. It adds 174 tokens to every session and 1,541 once invoked, about $0.0007 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Analytics and metrics Security agent-skills ai-agents bazel claude integration-platform local-first

netmon next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
netmonlarsboes/Axon	Skill	1	1mo ago	MIT	B	174	Claude Code
ligandmpnnaipoch/open-science	Skill	5.5k	today	Apache-2.0	A	100	Claude Code, Codex
evo2aipoch/open-science	Skill	5.5k	today	Apache-2.0	A	83	Claude Code, Codex
create-agentPM-Shawn/Abu-Cowork	Skill	419	3d ago	Apache-2.0	A	13	Claude Code
content-monitorCoWork-OS/CoWork-OS	Skill	537	today	MIT	A	16	Claude Code, Codex
llm-wikiCoWork-OS/CoWork-OS	Skill	537	today	MIT	A	27	Claude Code, Codex
simplifyCoWork-OS/CoWork-OS	Skill	537	today	MIT	A	24	Claude Code, Codex

netmon

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade B, and why

Asks for rootmediumPrivilege escalation

How it starts

netmon

Configuration

Run

What ships with it

What this file has done since we first saw it

netmon compared with skills from other repositories