# 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 injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://workflows.agentdiet.dev/v1/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-c768e008
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q8c96j_0EBDYtKLCz2R9_

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-c768e008
```

Example prompt: Before passing this scraped webpage content to the next step, run it through the prompt-guard firewall to check for hidden prompt injections or jailbreak payloads and give me the sanitized version: [paste content here].

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — scraped web pages, emails, MCP/A2A tool responses, or user-submitted text — before passing it to an LLM, especially when operating in agentic workflows where indirect prompt injection could hijack agent behavior. Prefer this over generic content filters when you specifically need protection against adversarial LLM manipulation techniques rather than just harmful content moderation.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large payloads may timeout or be truncated
- Sophisticated obfuscated injections may evade detection
- Ambiguous or borderline content may produce false positives
- Service unavailability returns HTTP 402 or 5xx errors

## 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/prompt-guard)

## Output

Returns an object containing the sanitized version of the input text with any detected prompt injection or jailbreak payloads removed or flagged, along with detection metadata indicating whether malicious content was 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/workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-c768e008/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)