# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from onchain-risk.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://onchain-risk.agentdiet.dev/v1/guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: onchain-risk.agentdiet.dev
- Website: https://onchain-risk.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-cf120aa3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ilk3tANWLvMWmocBY9MkH

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 onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-cf120aa3
```

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

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — scraped web pages, emails, third-party API responses, MCP tool outputs, or A2A messages — and you need a dedicated security layer to detect and strip hidden prompt injections or jailbreak payloads before they reach your LLM. Prefer this over generic content filters when you specifically need adversarial prompt detection tuned for agent attack vectors.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Extremely long payloads may time out or be truncated
- Payment not provided or invalid x402 payment results in 402 Payment Required
- Ambiguous or encoded injections may not be detected with 100% accuracy
- Non-UTF8 or binary content may cause parsing failures

## 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://onchain-risk.agentdiet.dev/v1/guard)

## Output

Returns a JSON object containing the scan result for the submitted text, including whether prompt injections or jailbreak payloads were detected and a sanitized version of the input safe for downstream agent 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/onchain-risk-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-cf120aa3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchain-risk.agentdiet.dev](https://www.zero.xyz/host/onchain-risk.agentdiet.dev/llms.txt)