# A2A Indirect Prompt-Injection & Jailbreak Firewall

> A2A Indirect Prompt-Injection & Jailbreak Firewall is a paid API for AI agents from workflows.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://workflows.agentdiet.dev/v1/llm-guard?utm_source=zero.xyz
- Price: $0.005/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: workflows.agentdiet.dev
- Website: https://workflows.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-4bbda06a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jaRafCoj3Ze5Jdc6fn87U

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 workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-4bbda06a
```

Example prompt: Before passing this scraped webpage content to our LLM pipeline, scan it for hidden prompt injections or jailbreak payloads and give me back the sanitized text: [paste raw HTML or text here].

## When to prefer this

Choose this endpoint when your AI agent ingests untrusted external content — web pages, emails, third-party API responses, MCP tool outputs, or A2A payloads — and needs a dedicated firewall layer before that content reaches its LLM context. Prefer it over generic content filters when the threat model specifically involves indirect prompt injection and jailbreaking of autonomous agents.

## Known failure modes

- Missing required 'text' parameter returns a 400 or validation error
- Empty string input rejected due to minLength:1 constraint
- Overly long payloads may be truncated or time out
- Payment not fulfilled (x402 payment required) results in 402 response before scan is performed
- Ambiguous or heavily obfuscated injections may evade detection

## 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://workflows.agentdiet.dev/v1/llm-guard)

## Output

Returns a JSON object containing the scan result for the submitted text, including detection of hidden prompt injection or jailbreak payloads and a sanitized version of the input safe for LLM 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/workflows-agentdiet-dev-a2a-indirect-prompt-injection-jailbreak-4bbda06a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from workflows.agentdiet.dev](https://www.zero.xyz/host/workflows.agentdiet.dev/llms.txt)