# 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 injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://email-verify.agentdiet.dev/v1/prompt-firewall?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-97d6cc0a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RbNnxLklz0v3bLSQxv37O

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-97d6cc0a
```

Example prompt: Before you process that scraped web page content, run it through the prompt injection firewall to check for any hidden jailbreak instructions or embedded prompt manipulation — here's the raw HTML text to scan.

## When to prefer this

Choose this endpoint when your AI agent needs to process content from untrusted external sources — scraped web pages, forwarded emails, third-party API or MCP tool responses, or A2A payloads — before passing them to an LLM. It is specifically designed for the indirect prompt injection threat vector where malicious instructions are hidden inside external content rather than typed directly by a user. Prefer this over generic content filters when the threat model is LLM manipulation rather than spam or NSFW content.

## Known failure modes

- Missing or empty 'text' parameter returns a 400 validation error
- Extremely long text inputs may be truncated or time out
- Novel or obfuscated injection patterns may evade detection
- Non-text binary content may not be parsed correctly
- Payment not completed (x402) results in 402 Payment Required response

## 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-firewall)

## Output

Returns a JSON object containing the scan result for the submitted text, including detection of any hidden prompt injection payloads or jailbreak attempts and a sanitized version of the input text safe for further LLM processing.

## 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-97d6cc0a/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)