# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from sec-intel.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 injection and jailbreak attacks, returning sanitized text.

## Facts

- Endpoint: POST https://sec-intel.agentdiet.dev/v1/system-prompt-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: sec-intel.agentdiet.dev
- Website: https://sec-intel.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/sec-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-7d113071
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1EYu_fHvU8y0Kvgz8i6mi

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 sec-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-7d113071 -d '<json body>'
```

Example prompt: Before processing this scraped webpage content, run it through the prompt injection firewall to check for any hidden instructions or jailbreak payloads trying to hijack you, and give me the sanitized version if it's safe.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — web pages, emails, third-party API responses, MCP tool outputs, or user-submitted text — and you need a dedicated security layer to detect and neutralize indirect prompt injection and jailbreak attempts before the content reaches your LLM. Prefer this over ad-hoc prompt hardening when operating autonomous A2A or MCP agent chains where a compromised upstream tool could redirect agent behavior.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely large payloads may exceed size limits or time out
- Obfuscated or novel injection techniques may evade detection
- Payment failure via x402 returns 402 with payment requirements
- Service unavailability returns 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://sec-intel.agentdiet.dev/v1/system-prompt-guard)

## Output

Returns a structured object containing the scan verdict (whether injection or jailbreak payloads were detected) and sanitized text with any malicious instructions stripped or neutralized, allowing safe downstream processing by the agent.

## 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/sec-intel-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-7d113071/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sec-intel.agentdiet.dev](https://www.zero.xyz/host/sec-intel.agentdiet.dev/llms.txt)