A tool that maps a device's MAC address, its network hardware identifier, to the company that registered it. It uses the IEEE OUI registry, a public list of hardware-vendor prefixes.

Looking up a vendor from a MAC address, finding registered address prefixes for a vendor, and viewing database statistics.

It helps identify unfamiliar devices when a network scan shows only hardware addresses instead of names.

oui-lookup — Skill for Claude Code and Codex by cheenu1092-oss/netmcp

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo

git clone --depth 1 https://github.com/cheenu1092-oss/netmcp

agentmods

npx agentmods add skills/cheenu1092-oss/netmcp/oui-lookup

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/cheenu1092-oss/netmcp/oui-lookup/github.svg)](https://agentmods.dev/skills/cheenu1092-oss/netmcp/oui-lookup)

Your own site

<a href="https://agentmods.dev/skills/cheenu1092-oss/netmcp/oui-lookup"><img src="https://agentmods.dev/badge/skills/cheenu1092-oss/netmcp/oui-lookup/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/cheenu1092-oss/netmcp/oui-lookup"><img src="https://agentmods.dev/badge/skills/cheenu1092-oss/netmcp/oui-lookup.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 450 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. 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	$0.00055	$0.00450
Opus 5.5	$0.00022	$0.00180
Sonnet 5.5	$0.00011	$0.00090
Haiku 4.5	$0.00006	$0.00045

Measured 2mo ago against content hash 7a1b10e505be, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

oui-lookup scanned grade A with 0 findings 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.

The scan reads SKILL.md. This mod also ships 4 executable files (scripts/install-mcp.sh, scripts/lookup.sh, scripts/search.sh, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/oui-lookup/SKILL.md · 61 lines

What it actually says

OUI Lookup — IEEE MAC Address Vendor Resolution

CLI Usage (Quick & Easy)

Simple bash wrapper scripts for direct command-line use:

cd ./skills/oui-lookup/scripts

# Lookup a MAC address
./lookup.sh AA:BB:CC:DD:EE:FF

# Search for vendor by name
./search.sh "Cisco"

# Get database statistics
./stats.sh

MCP Server Setup

# Ensure the database exists
node SKILL_DIR/../../packages/oui-lookup/scripts/update-oui-db.js

# Run as MCP server
node SKILL_DIR/../../packages/oui-lookup/src/index.js

# Or install into Claude Code config
./scripts/install-mcp.sh

Tools Available

`oui_lookup` — Resolve MAC to vendor

Input: Any MAC format (AA:BB:CC:DD:EE:FF, AA-BB-CC, AABBCC) Returns: Vendor name, address, country

`oui_search` — Search by vendor name

Input: Vendor name query (e.g. "Cisco", "Apple") Returns: All matching OUI prefixes (up to limit)

`oui_stats` — Database statistics

Returns: Total entries, unique vendors, top 20 vendors by OUI count

Data Source

IEEE Standards Association OUI registry: standards-oui.ieee.org/oui/oui.txt Updated by running npm run update-db in the package directory. 50K+ entries.

Examples

"What vendor made the device at MAC AA:BB:CC:11:22:33?" → oui_lookup
"How many OUI prefixes does Cisco own?" → oui_search with query "Cisco"
"What are the top device manufacturers by registered MACs?" → oui_stats

Files

What ships with it

4 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 · 61 lines · 55 tokens per session scan A 7a1b10e505be

Subscribe to this mod's changes

oui-lookup is a skill published in the GitHub repository cheenu1092-oss/netmcp (0 stars, last pushed 18d ago), licensed MIT. It adds 55 tokens to every session and 450 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Hardware and IoT

oui-lookup next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
oui-lookupcheenu1092-oss/netmcp	Skill	0	18d ago	MIT	A	55	Claude Code, Codex
gke-compute-classesgoogle/skills	Skill	22k	yesterday	Apache-2.0	A	83	Claude Code, Codex
jetson-diagnosticNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	30	Claude Code, Codex
holoscan-install-wheelNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	34	Claude Code, Codex
offensive-z-waveSnailSploit/Claude-Red	Skill	10k	25d ago	MIT	A	113	Claude Code, Codex
doca-socket-relayNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	A	236	Claude Code, Codex
hsb-flashNVIDIA/skills	Skill	3.9k	yesterday	Apache-2.0	B	94	Claude Code