# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from serp-extract.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown (last checked 2026-10-23).

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: POST https://serp-extract.agentdiet.dev/v1/tool-poisoning-shield?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: serp-extract.agentdiet.dev
- Website: https://serp-extract.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/serp-extract-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-87d823f1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Qk0MpgDgbocP7bGuOivTT

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 serp-extract-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-87d823f1 -d '<json body>'
```

Example prompt: Before you process this scraped web page content, run it through the prompt-injection firewall first to check for any hidden jailbreak instructions and give me back the sanitized version: '<html>...untrusted content here...</html>'

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — web pages, emails, tool responses, or A2A payloads — and you need an automated, per-call firewall to strip or flag hidden prompt injection and jailbreak attempts before that content reaches your LLM. Prefer this over manual filtering when operating in adversarial environments or when your agent interacts with untrusted third-party MCP servers or A2A agents.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely large payloads may exceed input size limits
- False negatives possible — novel or obfuscated injection patterns may not be detected
- Service unavailable (503) if the underlying firewall model is overloaded
- Payment required (402) if USDC balance is insufficient for the $0.005 per-call fee

## 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://serp-extract.agentdiet.dev/v1/tool-poisoning-shield)

## Output

Returns a JSON object containing the sanitized version of the input text with detected prompt injection or jailbreak content removed or flagged, along with detection metadata indicating whether threats were 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/serp-extract-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-87d823f1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from serp-extract.agentdiet.dev](https://www.zero.xyz/host/serp-extract.agentdiet.dev/llms.txt)