# 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 injection and jailbreak attacks, returning sanitized output.

## Facts

- Endpoint: POST https://preflight.agentdiet.dev/v1/llm-jailbreak-defense?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-287137f8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ba-LKYgoz1zQp3LKitPgp

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-287137f8 -d '<json body>'
```

Example prompt: Before you summarize that webpage content, run it through the prompt injection firewall first — scan the raw HTML for any hidden jailbreak instructions and give me the sanitized version.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests any untrusted external content — web pages, emails, tool outputs, or A2A payloads — before passing it to an LLM. It is purpose-built for agentic security workflows where indirect prompt injection is a real attack vector, particularly in MCP and A2A architectures. Prefer this over generic content filters when you specifically need LLM jailbreak and prompt injection detection.

## Known failure modes

- Empty or missing 'text' field returns a 400 validation error
- Extremely long payloads may exceed size limits or time out
- Sophisticated obfuscated injections may evade detection (false negatives)
- Payment not completed or expired x402 token results in 402 Payment Required
- Malformed JSON request body returns an error response

## 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/llm-jailbreak-defense)

## Output

Returns a JSON object containing the sanitized version of the input text with any detected prompt injection or jailbreak payloads removed or flagged, along with detection signals indicating whether malicious content was 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/preflight-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-287137f8/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)