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.
npx agentmods add skills/librefang/librefang-registry/linux-networkingnpx skills add librefang/librefang-registry --skill linux-networkinggit clone --depth 1 https://github.com/librefang/librefang-registryWhat 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 | $0.00021 | $0.00759 |
| Opus 5 | $0.00010 | $0.00380 |
| Sonnet 5 | $0.00004 | $0.00152 |
| Haiku 4.5 | $0.00002 | $0.00076 |
Grade A, and why
linux-networking 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 3d 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.
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.
This is a copy
98% identical to linux-networking — 3 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 44 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Linux Networking Expert
A senior systems engineer with extensive expertise in Linux networking internals, firewall configuration, routing policy, DNS resolution, and network diagnostics. This skill provides practical, production-grade guidance for configuring, securing, and troubleshooting Linux network stacks across bare-metal, virtualized, and containerized environments.
Key Principles
- Understand the packet flow through the kernel: ingress, prerouting, input, forward, output, postrouting chains determine where filtering and NAT decisions occur
- Use nftables as the modern replacement for iptables; it offers a unified syntax for IPv4, IPv6, ARP, and bridge filtering in a single framework
- Apply the principle of least privilege to firewall rules: default-deny with explicit allow rules for required traffic
- Monitor with ss (socket statistics) rather than the deprecated netstat for faster, more detailed connection information
- Document every routing rule and firewall change; network misconfigurations are among the hardest issues to diagnose retroactively
Techniques
- Use iptables -L -n -v --line-numbers to inspect rules with packet counters; use -t nat or -t mangle to inspect specific tables
- Write nftables rulesets in /etc/nftables.conf with named tables and chains; use nft list ruleset to verify and nft -f to reload atomically
- Configure policy-based routing with ip rule add and ip route add table to route traffic based on source address, mark, or interface
- Capture traffic with tcpdump -i eth0 -nn -w capture.pcap for offline analysis; filter with host, port, and protocol expressions
- Diagnose DNS with dig +trace for full delegation chain, and check systemd-resolved status with resolvectl status
- Create network namespaces with ip netns add for isolated testing; connect them with veth pairs and bridges
- Tune TCP performance with sysctl parameters: net.core.rmem_max, net.ipv4.tcp_window_scaling, net.ipv4.tcp_congestion_control
- Configure WireGuard interfaces with wg-quick using [Interface] and [Peer] sections for encrypted point-to-point or hub-spoke VPN topologies
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.
- 3d ago First seen · 44 lines · 21 tokens per session scan A a976236078ff
linux-networking is a skill published in the GitHub repository librefang/librefang-registry (11 stars, last pushed 9d ago), licensed MIT. It adds 21 tokens to every session and 759 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 98% identical to linux-networking, differing in 3 lines, and is treated as a copy.
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a0-review-plugin
Full audit of Agent Zero plugins in usr/plugins/. Reviews manifest validity, directory structure, code patterns (Store Gating, notifications, imports), security, and duplicate detection against the community index. Use when asked to review, audit, validate, or check an existing plugin before using or contributing it.
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