# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from preflight.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://preflight.agentdiet.dev/v1/indirect-injection-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-b7b7e892
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xceZUa8mVS8akcrSdgckf

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 preflight-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-b7b7e892 -d '<json body>'
```

Example prompt: Before you process this webpage I just scraped, run it through the prompt injection firewall to check for any hidden instructions or jailbreak attempts embedded in the text and give me the sanitized version.

## When to prefer this

Choose this endpoint when your AI agent is consuming untrusted external content — scraped web pages, inbound emails, third-party API responses, MCP tool outputs, or A2A messages — and you need a dedicated firewall layer to detect and neutralize hidden prompt injections or jailbreak attempts before they reach your LLM. Prefer this over generic content filters when you specifically need protection against adversarial AI-targeting attacks rather than general spam or malware.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely long payloads may be truncated or rejected
- Novel obfuscation techniques may evade detection (false negatives)
- Non-text binary content may not parse correctly
- Service unavailable returns 503; retry with Idempotency-Key to avoid double-billing
- Payment failure via x402 returns 402 and blocks execution

## 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://preflight.agentdiet.dev/v1/indirect-injection-guard)

## Output

Returns an object containing the sanitized version of the input text with prompt injections removed or neutralized, along with detection signals indicating whether injection or jailbreak content was found and what was stripped or flagged.

## 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/preflight-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-b7b7e892/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)