# A2A Indirect Prompt-Injection & Jailbreak Firewall

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

## Facts

- Endpoint: POST https://mesh.agentdiet.dev/v1/guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: mesh.agentdiet.dev
- Website: https://mesh.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-f5333907
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YAKghNo_WrrqFogr6k7hp

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 mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-f5333907 -d '<json body>'
```

Example prompt: Before you process that scraped webpage, run the raw HTML through the prompt-injection firewall and give me back the sanitized version — I don't want any hidden instructions slipping into your context.

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests content from untrusted external sources — scraped web pages, inbound emails, third-party API responses, MCP tool outputs, or A2A messages — and you need a dedicated, purpose-built firewall to detect and neutralize hidden prompt injection or jailbreak payloads before they reach your LLM context. Prefer this over generic content moderation APIs when the threat model is specifically adversarial instructions targeting AI agents rather than harmful user-facing content.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Extremely large payloads may time out or be rejected
- Payment not included or invalid x402 credentials returns a 402 Payment Required error
- Malformed request body returns a 400 Bad Request
- Service unavailable returns a 503 error

## 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://mesh.agentdiet.dev/v1/guard)

## Output

Returns a JSON object containing the scan result for the submitted text, including whether prompt injection or jailbreak content was detected and a sanitized version of the input text safe for agent consumption.

## 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/mesh-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-firewall-f5333907/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mesh.agentdiet.dev](https://www.zero.xyz/host/mesh.agentdiet.dev/llms.txt)