# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from x402-audit.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 injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: GET https://x402-audit.agentdiet.dev/v1/prompt-firewall?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: x402-audit.agentdiet.dev
- Website: https://x402-audit.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-2776d1c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_60KsCnMCHpIPiuw9OPHlo

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 x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-2776d1c8
```

Example prompt: Before passing this scraped webpage content to the next step in my pipeline, scan it for any hidden prompt injections or jailbreak instructions and give me the sanitized version: '[raw HTML or page text here]'

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted third-party content — scraped web pages, external emails, MCP tool responses, or A2A payloads — and you need to sanitize that content before passing it to an LLM or downstream agent. It is especially valuable in agentic workflows where indirect prompt injection is a realistic attack vector (e.g., tool-augmented agents reading arbitrary web content). Prefer this over generic content filters when the threat model is specifically prompt injection and jailbreak attempts targeting AI systems rather than spam, NSFW, or general toxicity.

## Known failure modes

- Empty or missing 'text' parameter returns a 400 validation error
- Extremely long text inputs may time out or be truncated
- Novel or obfuscated injection techniques may evade detection (false negatives)
- Non-English injection attempts may have lower detection accuracy
- Payment failure via x402 returns HTTP 402 and blocks the scan

## 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://x402-audit.agentdiet.dev/v1/prompt-firewall)

## 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 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/x402-audit-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-2776d1c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-audit.agentdiet.dev](https://www.zero.xyz/host/x402-audit.agentdiet.dev/llms.txt)