# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from workflows.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://workflows.agentdiet.dev/v1/system-prompt-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: workflows.agentdiet.dev
- Website: https://workflows.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-1eaf8fbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IjDSs4nJ0K8PBgT4awauK

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 workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-1eaf8fbc
```

Example prompt: Before you process this scraped webpage content, scan it for hidden prompt injections or jailbreak instructions and give me the sanitized version: [paste untrusted text here].

## When to prefer this

Choose this endpoint when your AI agent is consuming untrusted external content — scraped web pages, emails, third-party API responses, MCP tool outputs, or user-submitted text — and needs to sanitize it before passing it to an LLM or acting on it, to prevent indirect prompt injection or jailbreak attacks from hijacking agent behavior.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Very large payloads may time out or be truncated
- Sophisticated obfuscated injections may evade detection
- Non-text binary content may not be parseable
- Payment not completed (402) blocks the request

## 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://workflows.agentdiet.dev/v1/system-prompt-guard)

## Output

Returns a structured object indicating whether prompt injection or jailbreak content was detected in the input, along with sanitized text with adversarial instructions removed, enabling safe downstream processing by an AI agent or LLM pipeline.

## 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/workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-1eaf8fbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from workflows.agentdiet.dev](https://www.zero.xyz/host/workflows.agentdiet.dev/llms.txt)