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 skills add UnboundCompute/security-agent-skills --skill hunting-server-side-and-edge-side-includesgit clone --depth 1 https://github.com/UnboundCompute/security-agent-skillsWrote 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.
[](https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-server-side-and-edge-side-includes)<a href="https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-server-side-and-edge-side-includes"><img src="https://agentmods.dev/badge/skills/unboundcompute/security-agent-skills/hunting-server-side-and-edge-side-includes/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.
<a href="https://agentmods.dev/skills/unboundcompute/security-agent-skills/hunting-server-side-and-edge-side-includes"><img src="https://agentmods.dev/badge/skills/unboundcompute/security-agent-skills/hunting-server-side-and-edge-side-includes.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00193 | $0.02089 |
| Opus 5.5 | $0.00077 | $0.00836 |
| Sonnet 5.5 | $0.00039 | $0.00418 |
| Haiku 4.5 | $0.00019 | $0.00209 |
Grade A, and why
hunting-server-side-and-edge-side-includes 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hunting server-side and edge-side includes: when a directive is reflected
Two different tiers can turn reflected text into an executed directive. On the origin, a server with server-side includes enabled scans documents for directives and will read a file or run a command when it finds one, so untrusted input reflected into such a document and interpreted as a directive becomes file disclosure or command execution. At the edge, a cache, content-delivery network, or reverse proxy may parse edge-side include tags in responses and act on them, fetching a URL, splicing a fragment, or reading a request variable, so a reflected tag becomes server-side request forgery into the internal network, a poisoned shared cache, or a page that copies the victim's cookie back to the attacker. The edge variant is insidious: the application developer never wrote include handling and cannot see it in the origin code, because a separate tier performs it. You find both by locating reflection into processed documents and determining which processor sits in the path.
When to use
- Untrusted input is reflected into a page, template, or fragment served by an include-capable server.
- A cache, content-delivery network, or reverse proxy in front of the origin may parse edge-side includes.
- Response surfaces (headers, error pages, cached fragments) echo input into documents processed downstream.
Scope check
Test include injection only against systems you own or are authorized to assess, on non-production infrastructure, because a confirming directive can read server files, reach internal services, or poison a cache shared by other users. Prefer benign, observable probes over destructive commands, and coordinate before touching a shared cache. If you can't name the authorization, stop.
The loop
- Establish that an include processor is actually in the path first. Determine whether the origin has server-side includes enabled for the served document type, or whether a downstream cache, delivery network, or proxy parses edge-side include tags. This is the false-positive killer: if no processor interprets includes, reflected directive text is inert markup and there is no bug. Name the processor and the tier that runs it before treating any reflection as a lead.
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.
- 1mo ago First seen · 141 lines · 193 tokens per session scan A 802c1d988ca1
hunting-server-side-and-edge-side-includes is a skill published in the GitHub repository UnboundCompute/security-agent-skills (5 stars, last pushed 1mo ago), licensed MIT. It adds 193 tokens to every session and 2,089 once invoked, about $0.0008 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 2026-09-05.
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