# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from shopify-spy.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-23).

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: POST https://shopify-spy.agentdiet.dev/v1/guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: shopify-spy.agentdiet.dev
- Website: https://shopify-spy.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/shopify-spy-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-82e21ccf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HwwUkRCZLlDo4i-e9yqUw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability shopify-spy-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-82e21ccf -d '<json body>'
```

Example prompt: Before you process this scraped product page, run it through the prompt-injection firewall to make sure there are no hidden jailbreak instructions embedded in the HTML: [paste content here].

## When to prefer this

Choose this endpoint when your AI agent pipeline consumes untrusted external content — scraped web pages, emails, third-party API responses, MCP tool outputs, or A2A messages — and you need a dedicated firewall step to neutralize hidden prompt injections before the content reaches your LLM. Prefer it over generic content filtering when the threat model is specifically adversarial prompt injection or jailbreak payloads embedded in otherwise legitimate-looking text.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely long payloads may hit size limits or time out
- Ambiguous or benign-looking injections may not be detected with 100% accuracy
- Payment failure (402) if x402 micropayment is not properly attached
- Malformed HTML that the scanner cannot parse may return partial results

## How this service works

Scans untrusted web pages, emails, MCP responses, or A2A payloads for hidden prompt injections and returns sanitized text. (Live x402 v2, IETF MPP & MCP endpoint at https://shopify-spy.agentdiet.dev/v1/guard)

## Output

Returns a JSON object containing the sanitized version of the input text with any detected prompt injection or jailbreak content removed or flagged, along with detection metadata indicating whether threats were found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "text"
 ],
 "properties": {
  "text": {
   "type": "string",
   "minLength": 1,
   "description": "Untrusted text, HTML, or tool output to scan for hidden prompt injection or jailbreak payloads"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/shopify-spy-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-82e21ccf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from shopify-spy.agentdiet.dev](https://www.zero.xyz/host/shopify-spy.agentdiet.dev/llms.txt)