# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from mcp-security.agentdiet.dev, paid per call via MPP, $0.005/call, status unknown.

Scans untrusted text, HTML, emails, MCP responses, or A2A payloads for hidden prompt injections and jailbreak attempts, returning sanitized output.

## Facts

- Endpoint: POST https://mcp-security.agentdiet.dev/v1/mcp-security?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Activations on Zero: 0
- Provider: mcp-security.agentdiet.dev
- Website: https://mcp-security.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/mcp-security-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-ba9b90b3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_s0Mi7BS4hwUUjBjPhJqNJ

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 mcp-security-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-ba9b90b3 -d '<json body>'
```

Example prompt: Before you process this scraped webpage content, run it through the prompt injection firewall to make sure there are no hidden jailbreak instructions embedded in the text: [paste HTML or text here].

## When to prefer this

Choose this endpoint when your AI agent pipeline ingests untrusted external content — web pages, emails, third-party API responses, or A2A/MCP payloads — and you need to sanitize that content before passing it to an LLM. It is especially valuable in agentic workflows where indirect prompt injection is a realistic attack vector. Prefer this over manual filtering when you need automated, scalable detection purpose-built for LLM security contexts.

## Known failure modes

- Empty or missing 'text' field returns a validation error
- Extremely large payloads may time out or hit size limits
- Sophisticated obfuscated injections may evade detection (false negatives)
- Payment not attached or invalid x402 credentials result in 402 Payment Required
- Malformed JSON body returns a 400 Bad Request

## 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://mcp-security.agentdiet.dev/v1/mcp-security)

## Output

Returns a JSON object containing the sanitized version of the input text and flags indicating whether prompt injection or jailbreak content was detected, allowing the calling agent to safely use the cleaned output or reject the payload.

## 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/mcp-security-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-ba9b90b3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-security.agentdiet.dev](https://www.zero.xyz/host/mcp-security.agentdiet.dev/llms.txt)