# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from email-verify.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 injection and jailbreak attacks, returning sanitized output.

## Facts

- Endpoint: GET https://email-verify.agentdiet.dev/v1/prompt-injection-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: email-verify.agentdiet.dev
- Website: https://email-verify.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/email-verify-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-466278d1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kExnPw8l3DHyF5cdXekm7

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 email-verify-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-466278d1
```

Example prompt: Before you summarize this webpage I just scraped, run it through the prompt injection firewall first — I want to make sure there are no hidden adversarial instructions embedded in the HTML that could hijack your behavior.

## When to prefer this

Choose this endpoint when your AI agent is about to process untrusted external content — scraped web pages, user-submitted text, emails, third-party API responses, or A2A messages — and you need a dedicated security layer to detect and strip prompt injection or jailbreak payloads before they reach your LLM. It is especially valuable in agentic pipelines where indirect prompt injection via the environment (websites, tool outputs, external documents) is a known attack vector.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely long payloads may time out or be truncated
- Obfuscated or novel injection techniques may evade detection
- Non-English or encoded injections may reduce detection accuracy
- Service unavailability returns a 402 or 5xx error if payment or server issues occur

## 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://email-verify.agentdiet.dev/v1/prompt-injection-shield)

## Output

Returns an object indicating whether prompt injection or jailbreak content was detected in the submitted text, along with sanitized output that has had any adversarial instructions removed or neutralized, enabling safe downstream processing by AI agents.

## 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/email-verify-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-466278d1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from email-verify.agentdiet.dev](https://www.zero.xyz/host/email-verify.agentdiet.dev/llms.txt)