# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from hn-pulse.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 content.

## Facts

- Endpoint: GET https://hn-pulse.agentdiet.dev/v1/rag-poison-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: hn-pulse.agentdiet.dev
- Website: https://hn-pulse.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-59900c07
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OuG77MF2o9zewvKIG5zWu

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 hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-59900c07
```

Example prompt: Before you process the content from that scraped webpage, run it through the prompt injection firewall to check for any hidden jailbreak instructions and give me back the sanitized version.

## When to prefer this

Use this endpoint when your AI agent or pipeline ingests content from untrusted external sources — scraped web pages, user-submitted text, emails, MCP server responses, or A2A tool outputs — before passing that content to an LLM or acting on it. It is especially valuable in RAG pipelines, autonomous agent loops, and multi-agent orchestration scenarios where indirect prompt injection is a real attack surface. Prefer it over generic content filters when you specifically need prompt-injection and jailbreak detection rather than general toxicity or spam filtering.

## Known failure modes

- Empty or missing 'text' parameter returns a validation error
- Extremely large text inputs may be truncated or rejected
- False negatives possible for novel or highly obfuscated injection techniques
- HTTP 402 Payment Required if x402 payment header is absent or invalid
- Service unavailability may return 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://hn-pulse.agentdiet.dev/v1/rag-poison-shield)

## Output

Returns a JSON object containing the scan result for the submitted text, including detection of any hidden prompt injection or jailbreak payloads and a sanitized version of the input text safe for downstream agent or 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/hn-pulse-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-59900c07/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from hn-pulse.agentdiet.dev](https://www.zero.xyz/host/hn-pulse.agentdiet.dev/llms.txt)