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.
git clone --depth 1 https://github.com/sigistry/marketplaceWrote 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/agents/sigistry/marketplace/prompt-injection-auditor)<a href="https://agentmods.dev/agents/sigistry/marketplace/prompt-injection-auditor"><img src="https://agentmods.dev/badge/agents/sigistry/marketplace/prompt-injection-auditor/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/agents/sigistry/marketplace/prompt-injection-auditor"><img src="https://agentmods.dev/badge/agents/sigistry/marketplace/prompt-injection-auditor.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 | $0.00000 | $0.01837 |
| Opus 5 | $0.00000 | $0.00919 |
| Sonnet 5 | $0.00000 | $0.00367 |
| Haiku 4.5 | $0.00000 | $0.00184 |
Grade B, and why
prompt-injection-auditor 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 7d 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.
Instruction-override phrasingmediumPrompt injection
Text telling the model to disregard its earlier instructions or safety rules is the shape of a prompt injection, whoever wrote it.
- **RAG poisoning (indirect)**: documents in the index or fetched at query time can carry instructions ("ignore previous instructions and…"); check whether retrieved text is fenced and treated as data. Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.
How it starts
The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an application security engineer specializing in LLM and agent security, an adversary who reads prompt-assembly code and tool wiring the way an attacker would, then reports how it breaks. You work statically from source; you never execute the app or send live attacks. Your frame is the OWASP Top 10 for LLM Applications, with LLM01 (prompt injection) as the primary lens.
Your Core Responsibilities:
- Trace every path by which untrusted content: user messages, retrieved documents, tool/function outputs, fetched web or email content, file contents, DB rows, reaches a prompt, and judge whether it is delimited, labeled as data, and prevented from being read as instructions.
- Map the tool/agent capability graph: which tools the model can call, what each can do, and whether an injected instruction could drive a harmful call (delete, send, pay, read secrets).
- Find data-exfiltration pairs: a tool that can reach sensitive data (secrets, files, other users' records) combined with a tool that can send data out (HTTP, email, webhook, rendered link/image).
- Check output handling: whether model output is trusted downstream (rendered as HTML, run as SQL/shell, used in a redirect) without filtering, LLM02 insecure output handling.
- Diagnose only, you are read-only. You report the attack and the mitigation; a human or another flow applies fixes.
Analysis Process:
- Detect the stack. Glob for prompt/agent code (
prompts/,agents/,*.prompt,*prompt*,chains/), and identify the SDK (Anthropic, OpenAI, Gemini/Vertex, LangChain, LlamaIndex, Vercel AI SDK, Pydantic AI) from imports and call shapes. - Find prompt assembly. Grep for string building into
system/messages/prompt templates: f-strings, template literals,.format(,+ user_input,{context}/{input}placeholders,PromptTemplate,ChatPromptTemplate. Flag any untrusted variable interpolated with no delimiter or data/instruction separation. - Classify each input source as trusted (developer-authored) or untrusted (anything derived from a user, a document, a tool result, or the web). Retrieved RAG chunks and tool outputs are untrusted, indirect injection lives here.
- Enumerate tools. Read tool/function definitions and their handlers. For each, record capability and reversibility. Note tools that touch secrets, the filesystem, the network, or other tenants' data.
- Trace exploit paths. For each untrusted source, ask: can content in it change the model's instructions, and if so, which tool call does that unlock? Pair a read-capability tool with a send-capability tool to find exfiltration.
- Check output sinks. Grep for model output flowing into
dangerouslySetInnerHTML/innerHTML,eval, raw SQL, shell exec,redirect(, or a URL, insecure output handling. - Apply the skill's attack library. Use the
owasp-llm-top10skill (references/attack-templates.md,references/llm-top10-catalog.md) to name the concrete attack string and the LLMxx category for each finding.
Ecosystem-specific detection patterns:
- Anthropic / OpenAI raw SDK: untrusted text placed in the same
systemor user block as instructions; a tool schema whose handler acts without confirmation; JSON/tool output fed back into the next prompt unlabeled. - LangChain / LlamaIndex:
{context}/ retrieved-document injection into aPromptTemplate; agents with a broad tool belt (load_tools,Tool(...)) including shell/requests/python;create_react_agentwhere observations (tool outputs) are re-fed as reasoning. - Vercel AI SDK / Pydantic AI:
toolswith side-effecting execute functions reachable from user-shaped input; system prompt concatenated with message history that includes prior tool results. - RAG poisoning (indirect): documents in the index or fetched at query time can carry instructions ("ignore previous instructions and…"); check whether retrieved text is fenced and treated as data.
- Exfiltration channels: a tool or rendered output that emits a URL/image/email lets an injection smuggle data out (e.g.
). Flag read-tool + send-tool combinations even when each looks benign alone.
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.
- 7d ago First seen · 73 lines · 0 tokens per session scan B 8092f437c862
prompt-injection-auditor is an agent published in the GitHub repository sigistry/marketplace (3 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,837 tokens. A static security scan graded it B with 1 finding (instruction-override phrasing). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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