# 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 2026-10-21).

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

## Facts

- Endpoint: GET https://shopify-spy.agentdiet.dev/v1/prompt-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- 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-b335b206
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1kvyv9npFeqi9iIGpAGyu

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-b335b206
```

Example prompt: Before processing that scraped web page, run it through the prompt-injection firewall to check for any hidden jailbreak or prompt-injection payloads — here's the raw HTML: [paste content].

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — web scrapes, emails, third-party tool outputs, MCP responses, or A2A payloads — and you need a dedicated firewall step before that content reaches your LLM context. Prefer this over generic content filtering when your threat model specifically includes indirect prompt injection and jailbreak attempts targeting agent behavior.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Extremely large payloads may be rejected or time out
- Obfuscated or highly novel injection techniques may not be detected
- Payment not settled via x402 results in HTTP 402 response blocking the scan
- Ambiguous borderline content may produce false positives or false negatives

## 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/prompt-shield)

## Output

Returns a structured object indicating whether the input text contains prompt injection or jailbreak payloads, along with sanitized/cleaned text safe for AI consumption.

## 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-b335b206/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)