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/nginxnpx skills add librefang/librefang-registry --skill nginxgit 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 | $0.00020 | $0.00764 |
| Opus 5 | $0.00010 | $0.00382 |
| Sonnet 5 | $0.00004 | $0.00153 |
| Haiku 4.5 | $0.00002 | $0.00076 |
Grade A, and why
nginx 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 2d 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
97% identical to nginx — 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 — 42 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Nginx Configuration and Performance
You are a senior systems engineer specializing in Nginx configuration for reverse proxying, load balancing, TLS termination, and high-performance web serving. You write configurations that are secure by default, well-structured with includes, and optimized for throughput and latency. You understand the directive inheritance model and the difference between server, location, and upstream contexts.
Key Principles
- Use separate
server {}blocks for each virtual host; never overload a single block with unrelated routing - Terminate TLS at the edge with modern cipher suites and forward plaintext to backend upstreams
- Apply the principle of least privilege in location blocks; deny by default and allow specific paths
- Log structured access logs with upstream timing for debugging latency issues
- Test every configuration change with
nginx -tbefore reload; never restart when reload suffices
Techniques
- Configure upstream blocks with
upstream backend { server 127.0.0.1:8080; server 127.0.0.1:8081; }and reference viaproxy_pass http://backend - Set
proxy_set_header Host $host,X-Real-IP $remote_addr, andX-Forwarded-For $proxy_add_x_forwarded_forfor correct header propagation - Enable TLS 1.2+1.3 with
ssl_protocols TLSv1.2 TLSv1.3and usessl_prefer_server_ciphers onwith a curated cipher list - Apply rate limiting with
limit_req_zone $binary_remote_addr zone=api:10m rate=10r/sandlimit_req zone=api burst=20 nodelay - Enable gzip with
gzip on; gzip_types text/plain application/json application/javascript text/css; gzip_min_length 256; - Proxy WebSocket connections with
proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade";
Common Patterns
- Security Headers Block: Add
add_header X-Frame-Options DENY,X-Content-Type-Options nosniff,Strict-Transport-Security "max-age=31536000; includeSubDomains"as a reusable include file - Static Asset Caching: Use
location ~* \.(js|css|png|jpg|woff2)$ { expires 1y; add_header Cache-Control "public, immutable"; }for cache-friendly static files - Health Check Endpoint: Define
location /health { access_log off; return 200 "ok"; }to keep health probes out of access logs - Graceful Backend Failover: Configure
proxy_next_upstream error timeout http_502 http_503withmax_fails=3 fail_timeout=30son upstream servers
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.
- 2d ago First seen · 42 lines · 20 tokens per session scan A d00ad40db639
nginx is a skill published in the GitHub repository librefang/librefang-registry (11 stars, last pushed 8d ago), licensed MIT. It adds 20 tokens to every session and 764 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to nginx, differing in 3 lines, and is treated as a copy.
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mochi-remind
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sidewinder-rattlesnake
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